The China Mobile, Huawei, and ZTE BNG Simple Control and User Plane Separation Protocol (S-CUSP)
draft-chz-simple-cu-separation-bng-protocol-02
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 8772.
|
|
|---|---|---|---|
| Authors | Shujun Hu , Donald E. Eastlake 3rd , Mach Chen , Fengwei Qin , Zhenqiang Li , Tee Mong Chua | ||
| Last updated | 2019-06-24 (Latest revision 2019-06-14) | ||
| Replaces | draft-cuspdt-rtgwg-cu-separation-bng-protocol | ||
| RFC stream | (None) | ||
| Formats | |||
| IETF conflict review | conflict-review-chz-simple-cu-separation-bng-protocol, conflict-review-chz-simple-cu-separation-bng-protocol, conflict-review-chz-simple-cu-separation-bng-protocol, conflict-review-chz-simple-cu-separation-bng-protocol, conflict-review-chz-simple-cu-separation-bng-protocol, conflict-review-chz-simple-cu-separation-bng-protocol | ||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | Became RFC 8772 (Informational) | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-chz-simple-cu-separation-bng-protocol-02
INTERNET-DRAFT S. Hu
Intended status: Informational China Mobile
D. Eastlake
Futurewei Technologies
M. Chen
Huawei Technologies
F. Qin
Z. Li
China Mobile
T. Chua
Singapore Telecommunications
Expires: December 22, 2019 June 23, 2019
The China Mobile, Huawei, and ZTE BNG
Simple Control and User Plane Separation Protocol (S-CUSP)
draft-chz-simple-cu-separation-bng-protocol-02
Abstract
To support Control Plane (CP) and User Plane (UP) Separation (CUPS)
for fixed network Broadband Network Gateway (BNG) service providers,
China Mobile, Huawei Technologies, and ZTE have developed a simple
CUPS control channel Protocol (S-CUSP).
This document is not an IETF standard and does not have IETF
consensus. It is presented here to make the S-CUSP specification
conveniently available to the Internet community to enable diagnosis
and interoperability.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Distribution of this document is unlimited. Comments should be sent
to the authors.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
Hu, et al [Page 1]
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The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html. The list of Internet-Draft
Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
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Table of Contents
1. Introduction...........................................6
2. Terminology............................................7
2.1. Implementation Requirement Keywords................7
2.2. Terms..............................................7
3. BNG CUPS Overview.....................................10
3.1. BNG CUPS Motivation...............................10
3.2. BNG CUPS Architecture Overview....................10
3.3. BNG CUPS Interfaces...............................12
3.3.1. Service Interface...............................13
3.3.2. Control Interface...............................14
3.3.3. Management Interface............................14
3.4. BNG CUPS Procedure Overview.......................14
4. S-CUSP Protocol Overview..............................18
4.1. Control Channel Related Procedures................18
4.1.1. S-CUSP Session Establishment....................18
4.1.2. Keep Alive......................................19
4.2. Node Related Procedures...........................20
4.2.1. UP Resource Report..............................20
4.2.2. Update BAS Function on Access Interface.........21
4.2.3. Update Network Routing..........................21
4.2.4. CGN Public IP Address Allocation................22
4.2.5. Data Synchronization between the CP and UP......23
4.3. Subscriber Session Related Procedures.............24
4.3.1. Create Subscriber Session.......................25
4.3.2. Update Subscriber Session.......................26
4.3.3. Delete Subscriber Session.......................27
4.3.4. Subscriber Session Events Report................27
5. S-CUSP Call Flows.....................................29
5.1. IPoE..............................................29
5.1.1. DHCPv4 Access...................................29
5.1.2. DHCPv6 Access...................................30
5.1.3. IPv6 SLAAC Access...............................32
5.1.4. DHCPv6 + SLAAC Access...........................33
5.1.5. DHCP Dual Stack Access..........................35
5.1.6. L2 Static Subscriber Access.....................37
5.2. PPPoE.............................................40
5.2.1. IPv4 PPPoE Access...............................40
5.2.2. IPv6 PPPoE Access...............................41
5.2.3. PPPoE Dual Stack Access.........................43
5.3. WLAN Access.......................................45
5.4. L2TP..............................................47
5.4.1. L2TP LAC Access.................................47
5.4.2. L2TP LNS IPv4 Access............................49
5.4.3. L2TP LNS IPv6 Access............................51
5.5. CGN (Carrier Grade NAT)...........................54
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Table of Contents (continued)
5.6. L3 Leased Line Access.............................55
5.6.1. Web Authentication..............................55
5.6.2. User Traffic Trigger............................57
5.7. Multicast Access..................................58
6. S-CUSP Message Formats................................60
6.1. Common Message Header.............................60
6.2. Control Messages..................................61
6.2.1. Hello Message...................................61
6.2.2. Keepalive Message...............................62
6.2.3. Sync_Request Message............................62
6.2.4. Sync_Begin Message..............................62
6.2.5. Sync_Data Message...............................63
6.2.6. Sync_End Message................................63
6.2.7. Update_Request Message..........................64
6.2.8. Update_Response Message.........................64
6.3. Event Message.....................................65
6.4. Report Message....................................66
6.5. CGN Messages......................................66
6.5.1. Addr_Allocation_Req Message.....................66
6.5.2. Addr_Allocation_Ack Message.....................66
6.5.3. Addr_Renew_Req Message..........................67
6.5.4. Addr_Renew_Ack Message..........................67
6.5.5. Addr_Release_Req Message........................67
6.5.6. Addr_Release_Ack Message........................67
6.6. Vendor Message....................................67
6.7 Error Message.......................................68
7. S-CUSP TLVs and Sub-TLVs..............................69
7.1. Common TLV Header.................................69
7.2. Basic Data Fields.................................70
7.3. Sub-TLV Format and Sub-TLVs.......................71
7.3.1. Name sub-TLVs...................................71
7.3.2. Ingress-CAR sub-TLV.............................72
7.3.3. Egress-CAR sub-TLV..............................72
7.3.4. If-Desc sub-TLV.................................73
7.3.5. IPv6 Address List sub-TLV.......................75
7.3.6. Vendor sub-TLV..................................75
7.4. The Hello TLV.....................................77
7.5. The Keep Alive TLV................................78
7.6. The Error Information TLV.........................79
7.7. BAS Function TLV..................................79
7.8. Routing TLVs......................................82
7.8.1. IPv4 Routing TLV................................82
7.8.2. IPv6 Routing TLV................................84
7.9. Subscriber TLVs...................................85
7.9.1. Basic Subscriber TLV............................86
7.9.2. PPP Subscriber TLV..............................88
7.9.3. IPv4 Subscriber TLV.............................89
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Table of Contents (continued)
7.9.4. IPv6 Subscriber TLV.............................90
7.9.5. IPv4 Static Subscriber Detect TLV...............91
7.9.6. IPv6 Static Subscriber Detect TLV...............93
7.9.7. L2TP-LAC Subscriber TLV.........................94
7.9.8. L2TP-LNS Subscriber TLV.........................95
7.9.9. L2TP-LAC Tunnel TLV.............................95
7.9.10. L2TP-LNS Tunnel TLV............................96
7.9.11. Update Response TLV............................97
7.9.12. Subscriber Policy TLV..........................98
7.9.13. Subscriber CGN Port Range TLV.................100
7.10. Device Status TLVs..............................100
7.10.1. Interface Status TLV..........................101
7.10.2. Board Status TLV..............................101
7.11. CGN TLVs........................................102
7.11.1. Address Allocation Request TLV................102
7.11.2. Address Allocation Response TLV...............103
7.11.3. Address Renewal Request TLV...................104
7.11.4. The Address Renewal Response TLV..............105
7.11.5. Address Release Request TLV...................106
7.11.6. The Address Release Response TLV..............106
7.12. Event TLVs......................................107
7.12.1. Subscriber Traffic Statistics TLV..............108
7.12.2. Subscriber Detection Result TLV...............109
7.13. Vendor TLV......................................110
8. Implementation Status................................112
8.1. Implementations..................................112
8.1.1. Huawei Technologies............................112
8.1.2. ZTE............................................113
8.1.3. H3C............................................113
8.2. Hackathon........................................113
8.3. EANTC Testing....................................114
9. Summary of Major S-CUSP Codepoints...................115
9.1. Message Types....................................115
9.2. TLV Types........................................115
9.3. TLV Operation Codes..............................117
9.4. Sub-TLV Types....................................118
9.5. Error Codes......................................118
10. IANA Considerations.................................120
11. Security Considerations.............................121
Contributors.............................................122
Normative References.....................................123
Informative References...................................124
Authors' Addresses.......................................126
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1. Introduction
A fixed network Broadband Network Gateway (BNG) is an Ethernet-
centric IP edge router, and the aggregation point for user traffic.
To provide centralized session management, flexible address
allocation, high scalability for subscriber management capacity, and
cost-efficient redundancy, the Control/User (CU) separated BNG
framework is described in [TR-384]. The CU separated service Control
Plane (CP), which is responsible for user access authentication and
setting forwarding entries in User Planes (UPs), can be virtualized
and centralized. The routing control and forwarding plane, i.e. the
BNG user plane (local), can be distributed across the infrastructure.
Other structures can also be supported such as both CP and UP being
virtual or both being physical.
This document specifies the Simple CU Separation BNG control channel
Protocol (S-CUSP) for communications between a BNG Control Plane (CP)
and a set of User Planes (UPs). S-CUSP is designed to be flexible
and extensible so as to easily allow for additional messages and data
items, should further requirements be expressed in the future.
This document is not an IETF standard and does not have IETF
consensus. S-CUSP was designed by China Mobile, Huawei Technologies,
and ZTE, it is presented here to make the S-CUSP specification
conveniently available to the Internet community to enable diagnosis
and interoperability.
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2. Terminology
This section specifies implementation requirement keywords and terms
used in this document. S-CUSP messages are described in this document
using Routing Backus-Naur Form (RBNF) as defined in [RFC5511].
2.1. Implementation Requirement Keywords
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2.2. Terms
This section specifies terms used in this document.
AAA: Authentication Authorization Accounting.
ACK: Acknowledgement message.
BAS: Broadband Access Server (BRAS, BNG).
BNG: Broadband Network Gateway. A broadband remote access server
(BRAS (BRoadband Access Server), B-RAS or BBRAS) routes traffic
to and from broadband remote access devices such as digital
subscriber line access multiplexers (DSLAM) on an Internet
Service Provider's (ISP) network. BRAS can also be referred to
as a Broadband Network Gateway (BNG).
BRAS: BRoadband Access Server (BNG).
CAR: Committed Access Rate.
CBS: Committed Burst Size.
CGN: Carrier Grade NAT.
Ci: Control Interface.
CIR: Committed Information Rate.
CoA: Change of Authorization.
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CP: Control Plane.
CP is a user control management component which supports the
management of the UP's resources such as the user entry and
forwarding policy.
CPE: Customer Premises Equipment.
CU: Control-plane / User-plane.
CUSP: Control and User plane Separation Protocol.
DEI: Drop Eligibility Indicator. A bit in a VLAN tag after the
priority and before the VLAN ID. (This bit was formerly the CFI
(Canonical Format Indicator).) [802.1Q]
DHCP: Dynamic Host Configuration Protocol [RFC2131].
dial-up: This refers to the initial connection messages when a new
user appears. The name is left over from when users literally
dialed up on a modem equipped phone line but herein is applied to
other initial connection techniques. Initial connection is
frequently indicated by the receipt of packets over PPPoE
[RFC2516] or IPoE.
EMS: Element Management System.
IPoE: IP over Ethernet.
L2TP: Layer 2 Tunneling Protocol [RFC2661].
LAC: L2TP Access Concentrator.
LNS: L2TP Network Server.
MAC: 48-bit Media Access Control address [RFC7042].
MANO: Management and Orchestration.
Mi: Management Interface.
MSS: Maximum Segment Size.
MRU: Maximum Receive Unit.
NAT: Network Address Translation [RFC3022].
ND: Neighbor Discovery.
NFV: Network Function Virtualization.
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NFVI: NFV Infrastructure
PBS: Peak Burst Size.
PD: Prefix Delegation.
PIR: Peak Information Rate.
PPP: Point to Point Protocol [RFC1661].
PPPoE: PPP over Ethernet [RFC2516].
RBNF: Routing Backus-Naur Form [RFC5511].
RG: Residential Gateway.
S-CUSP: Simple Control and User Plane Separation Protocol.
Si: Service Interface.
TLV: Type, Length, Value. See Sections 7.1 and 7.3.
UP: User Plane. UP is a network edge and user policy implementation
component. The traditional router's Control Plane and Forwarding
Plane are both preserved on BNG devices in the form of a user
plane.
URPF: Unicast Reverse Path Forwarding.
User: Equivalent to "customer" or "subscriber".
VRF: Virtual Routing and Forwarding.
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3. BNG CUPS Overview
3.1. BNG CUPS Motivation
The rapid development of new services, such as 4K TV, IoT, etc., and
increasing numbers of home broadband service users present some new
challenges for BNGs such as:
Low resource utilization: The traditional BNG acts as both a gateway
for user access authentication and accounting and an IP network's
Layer 3 edge. The mutually affecting nature of the tightly
coupled control plane and forwarding plane makes it difficult to
achieve the maximum performance of either plane.
Complex management and maintenance: Due to the large numbers of
traditional BNGs, configuring each device in a network is very
tedious when deploying global service policies. As the network
expands and new services are introduced, this deployment mode
will cease to be feasible as it is unable to manage services
effectively and rectify faults rapidly.
Slow service provisioning: The coupling of control plane and
forwarding plane, in addition to a distributed network control
mechanism, means that any new technology has to rely heavily on
the existing network devices.
To address these challenges for fixed networks, the framework for a
cloud-based BNG with Control Plane and User Plane (CU) separation is
described in [TR-384]. The main idea of CU separation is to extract
and centralize the user management functions of multiple BNG devices,
forming a unified and centralized Control Plane (CP). And the
traditional router's Control Plane and Forwarding Plane are both
preserved on BNG devices in the form of a User Plane (UP).
3.2. BNG CUPS Architecture Overview
The functions in a traditional BNG can be divided into two parts: one
is the user access management function, the other is the router
function. The user management function can be centralized and
deployed as a concentrated module or device, called the BNG Control
Plane (BNG-CP). The other functions, such as the router function and
forwarding engine, can be deployed in the form of the BNG User Plane
(BNG-UP).
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The following figure shows the architecture of CU separated BNG:
+------------------------------------------------------------------+
| Neighboring policy and resource management systems |
| |
| +-------------+ +-----------+ +---------+ +----------+ |
| |AAA Server| |DHCP Server| | EMS | | MANO | |
| +-------------+ +-----------+ +---------+ +----------+ |
+------------------------------------------------------------------+
+------------------------------------------------------------------+
| CU-separated BNG system |
| +--------------------------------------------------------------+ |
| | +----------+ +----------+ +------++------++-----------+ | |
| | | Address | |Subscriber| | AAA ||Access|| UP | | |
| | |management| |management| | || Mgt ||management | | |
| | +----------+ +----------+ +------++------++-----------+ | |
| | CP | |
| +--------------------------------------------------------------+ |
| |
| |
| |
| +---------------------------+ +--------------------------+ |
| | +------------------+ | | +------------------+ | |
| | | Routing control | | | | Routing control | | |
| | +------------------+ | ... | +------------------+ | |
| | +------------------+ | | +------------------+ | |
| | |Forwarding engine | | | |Forwarding engine | | |
| | +------------------+ UP | | +------------------+ UP| |
| +---------------------------+ +--------------------------+ |
+------------------------------------------------------------------+
Figure 1: Architecture of CU Separated BNG
As shown in Figure 1, the BNG Control Plane could be virtualized and
centralized, which provides benefits such as centralized session
management, flexible address allocation, high scalability for
subscriber management capacity, and cost-efficient redundancy, etc.
The functional components inside the BNG Service Control Plane can be
implemented as Virtual Network Functions (VNFs) and hosted in a
Network Function Virtualization Infrastructure (NFVI).
The User Plane Management module in the BNG Control Plane centrally
manages the distributed BNG User Planes (e.g. load balancing), as
well as the setup, deletion, and maintenance of channels between
Control Planes and User Planes. Other modules in the BNG control
plane, such as address management, AAA, etc., are responsible for the
connection with outside subsystems in order to fulfill those
services. Note that the User Plane SHOULD support both physical and
virtual network functions. For example, BNG user plane L3 forwarding
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related network functions can be disaggregated and distributed across
the physical infrastructure. And the other control plane and
management plane functions in the CU Separation BNG can be moved into
the NFVI for virtualization [TR-384].
The details of CU separated BNG's function components are as
following:
The Control Plane is responsible for the following:
1. Address management: unified address pool management and CGN
subscriber address traceability management.
2. AAA: This component performs Authentication, Authorization and
Accounting, together with RADIUS/DIAMETER. The BNG communicates
with the AAA server to check whether the subscriber who sent an
Access-Request has network access authority. Once the subscriber
goes online, this component together with the Service Control
component implement accounting, data capacity limitation, and QoS
enforcement policies.
3. Subscriber management: user entry management and forwarding
policy management.
4. Access management: process user dial-up packets, such as PPPoE,
DHCP, L2TP, etc.
5. UP management: management of UP interface status, and the setup,
deletion, and maintenance of channels between CP and UP.
The User Plane is responsible for the following:
1. Routing control functions: responsible for constructing routing
forwarding plane (e.g., routing, multicast, MPLS, etc.).
2. Routing and Service Forwarding plane functions: responsible
including traffic forwarding, QoS and traffic statistics
collection.
Subscriber detection: responsible for detecting whether a subscriber
is still online.
3.3. BNG CUPS Interfaces
To support the communication between the Control Plane and User
Plane, three interfaces are assumed. These are referred to as the
Service Interface (Si), Control Interface (Ci), and Management
Interface (Mi) as shown in Figure 2.
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+-----------------------------------+
| |
| BNG-CP |
| |
+--+--------------+--------------+--+
| | |
1. Service | 2. Control | 3. Management|
Interface | Interface | Interface |
(Si) | (Ci) | (Mi) |
| | |
| ___|___ |
| ___( )___ |
_|______( )______|_
( )
( Network/Internet )
(________ ________)
| (___ ___) |
| (_______) |
| | |
| | |
+--+--------------+--------------+--+
| |
| BNG-UP |
| |
+-----------------------------------+
Figure 2: Interfaces Between the CP and UP of the BNG
3.3.1. Service Interface
For a traditional BNG (without CU separation), the user dial-up
signals are terminated and processed by the control plane of a BNG.
When the CP and UP of a BNG are separated, there needs to be a way to
relay these signals between the CP and the UP.
The Service Interface (Si) is used to establish tunnels between the
CP and UP. The tunnels are responsible for relaying the PPPoE, IPoE,
and L2TP related control packets that are received from a Residential
Gateway (RG) over those tunnels. An appropriate tunnel type is VXLAN
[RFC7348].
The detailed definition of Si is out of scope for this document.
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3.3.2. Control Interface
The CP uses the Control Interface to deliver subscriber session
states, network routing entries, etc. to the UP (see Section 6.2.7)).
The UP uses this interface to report subscriber service statistics,
subscriber detection results, etc. to the CP (see Sections 6.3 and
6.4). A carrying protocol for this interface is specified in this
document.
3.3.3. Management Interface
NETCONF [RFC6241] is the protocol used on the Management Interface
between a CP and UP. It is used to configure the parameters of the
Control Interface, Service Interface, the Access interfaces and
QoS/ACL Templates. It is expected that implementations will make use
of existing YANG models where possible, but that new YANG models
specific to S-CUSP will need to be defined. The definitions of the
parameters are out of scope for this document.
3.4. BNG CUPS Procedure Overview
The following numbered sequences (Figure 3) gives a high level view
of the main BNG CUPS procedures.
RG UP CP AAA
| | | |
| |Establish S-CUSP Channel| |
| 1|<---------------------->| |
| | | |
| | Report Board | |
| | interface | |
| | information | |
| 2|------to CP via Ci----->| |
| | | |
| | Update BAS function | |
| 3| request / response | |
| |<-----on UP via Ci----->| |
| | | |
| | Update network routing | |
| | request / response | |
| 4|<------- via Ci-------->| |
| | | |
| Online Req | | |
5.1|-------------->| | |
| | Relay the Online Req | |
| 5.2|-----to CP via Si------>| Authentication|
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| | | Req/Rep |
| | 5.3|<------------->|
| | Send the Online Rep | |
| 5.4|<----to UP via Si-------| |
| Online Rep | | |
5.5|<--------------| | |
| | Create subscriber | |
| | session on UP | |
| 5.6|<--------via Ci-------->| |
| | | CoA Request |
| | 6.1|<--------------|
| | Update session on UP | |
| 6.2|<--------via Ci-------->| |
| | | CoA Response |
| | 6.3|-------------->|
| | | |
| Offline Req | | |
7.1|-------------->| | |
| | Relay the Offline Req | |
| 7.2|------to CP via Si----->| |
| | | |
| | Send the Offline Rep | |
| 7.3|<-----to UP via Si------| |
| Offline Rep | | |
7.4|<--------------| | |
| | Delete session on UP | |
| 7.5|<--------via Ci-------->| |
| | | |
| | Event report | |
| 8|---------via Ci-------->| |
| | | |
| | Data Synchronization | |
| 9|<--------via Ci-------->| |
| | | |
| | CGN Address Allocation | |
| 10|<--------via Ci-------->| |
| | | |
Figure 3: BNG CUPS Procedures Overview
1. S-CUSP session establishment: This is the first step of BNG CUPS
procedures. Once the Control Interface parameters are configured
on a UP. It will start to setup S-CUSP sessions with the
specified CPs. The detailed definition of S-CUSP session
establishment can be found in Section 4.1.1.
2. Board and interface report: Once the S-CUSP session is
established between the UP and a CP, the UP will report status
information on the boards and subscriber side interfaces of this
UP to the CP. A board can also be called a Line/Service Process
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Unit (LPU/SPU) card. The subscriber side interfaces refer to the
interfaces that connect the Acess Network nodes (e.g., OLT:
Optical Line Terminal, DSLAM: Digital Subscriber Line Access
Multiplexer, etc.). The CP can use this information to enable the
Broadband Access Service (BAS) function (e.g., IPoE, PPPoE, etc.)
on the specified interfaces. See Sections 4.2.1 and 7.10 for more
details on Resource reporting.
3. BAS (Broadband Access Service) function enable: To enable the BAS
function on the specified interfaces of a UP.
4. Subscriber network route advertisement: The CP will allocate one
or more IP address blocks to a UP. Each address block contains a
series of IP addresses. Those IP addresses will be allocated to
subscribers who are dialing up from the UP. To enable other nodes
in the network to learn how to reach the subscribers, the CP
needs to notify the UP to advertise to the network the routes
that can reach those IP addresses.
5. 5.1-5.6 is a complete call flow of a subscriber dial-up process.
When a UP receives a dial-up request, it will relay the request
packet to a CP through the Service Interface. The CP will parse
the request. If everything is OK, it will send an authentication
request to the AAA server to authenticate the subscriber. Once
the subscriber passes the authentication, the AAA server will
return a positive response to the CP. Then the CP will send the
dial-up response packet to the UP and the UP will forward the
response packet to the subscriber (RG). At the same time, the CP
will create a subscriber session on the UP, which enables the
subscriber to access the network. For different access types,
the process may be a bit different. But the high-level process is
similar. For each access type, the detail process can be found in
Section 5.
6. 6.1-6.3 is the sequence when updating an existing subscriber
session. The AAA server initiates a Change of Authorization (CoA)
and sends the CoA to the CP. The CP will then update the session
according to the CoA. See Section 4.3.2 for more detail on CP
messages updating UP tables.
7. 7.1-7.5 is the sequence for deleting an existing subscriber
session. When a UP receives an offline request, it will relay the
request to a CP through the Service Interface. The CP will send
back a response to the UP through the Service Interface. The UP
will then forward the offline response to the subscriber. Then
the CP will delete the session on the UP through the Control
Interface.
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8. Event reports include the following two parts (more detail can be
found in Section 4.3.4) Both are reported using the Event
message.
8.1. Subscriber Traffic Statistics Report
8.2. Subscriber Detection Result Report
9. Data synchronization: See Sections 4.2.5 for more detail on CP
and UP Synchronization.
10. CGN address allocation: See Sections 4.2.4 for more detail on CGN
Address Allocation.
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4. S-CUSP Protocol Overview
4.1. Control Channel Related Procedures
4.1.1. S-CUSP Session Establishment
A UP is associated with a CP and is controlled by that CP. In the
case of a hot-standby or cold-standby, a UP is associated with two
CPs, one called the Master CP and the other called the Standby CP.
The association between a UP and its CPs is implemented by dynamic
configuration.
Once a UP knows its CPs, the UP starts to establish S-CUSP sessions
with those CPs as shown in Figure 4.
UP CP
| |
| TCP Session Establishment |
|<------------------------------->|
| |
| HELLO (version, capability) |
|-------------------------------->|
| |
| HELLO (version, capability) |
|<--------------------------------|
| |
Figure 4: S-CUSP Session Establishment
The S-CUSP session establishment consists of two successive steps:
1. Establishment of a TCP [RFC793] connection (3-way handshake)
between the CP and the UP using a configured port from the
dynamic port range (49152-65535).
2. Establishment of a S-CUSP session over the TCP connection.
Once the TCP connection is established, the CP and the UP initialize
the S-CUSP session during which the version and Keepalive timers are
negotiated.
The version information (Hello TLV, see Section 7.4) is carried
within Hello messages (see Section 6.2.1). A CP can support multiple
versions, but a UP can only support one version. So, the version
negotiation is based on whether a version can be support by both the
CP and the UP. For a CP or UP, if a Hello message is received that
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does not indicate a version supported by both, a subsequent Hello
message with an Error Information TLV will be sent to the peer to
notify the peer of the "Version-Mismatch" error and the session
establishment phase fails.
Keepalive negotiation is performed by carrying a Keepalive TLV in the
Hello message. The Keepalive TLV includes a Keepalive timer and Dead
Timer field. The CP and UP have to agree on the Keepalive Timer and
Dead Timer. Otherwise, a subsequent Hello message with an Error
Information TLV will be sent to its peer and the session
establishment phase fails.
The S-CUSP session establishment phase fails if the CP or UP disagree
on the version and keepalive parameters or if one of the CP or UP
does not answer after the expiration of the Establishment timer.
When the S-CUSP session establishment fails, the TCP connection is
promptly closed. Successive retries are permitted but an
implementation SHOULD make use of an exponential back-off session
establishment retry procedure.
The S-CUSP session timer values that need to be configured are
summarized in the table below.
Timer Range in Default
Name seconds Value
------------- ------- -------
Establishment 1-32767 45
Keepalive 0-255 30
DeadTimer 1-32767 4 * Keepalive
4.1.2. Keep Alive
Once an S-CUSP session has been established, a UP or CP may want to
know that its S-CUSP peer is still available for use.
Each end of a S-CUSP session runs a Keepalive timer. It restarts the
timer every time it sends a message on the session. When the timer
expires, it sends a Keepalive message.
The ends of the S-CUSP session also run DeadTimers, and they restart
the timers whenever a message is received on the session. If one end
of the session receives no message after the DeadTimer expires, it
declares the session dead. The session will be closed.
The minimum value of the Keepalive timer is 1 second, and it is
specified in units of 1 second. The RECOMMENDED default value is 30
seconds. The timer may be disabled by setting it to zero.
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The recommended default for the DeadTimer is 4 times the value of the
Keepalive timer used by the remote peer. This implies there is
essentially no risk of TCP congestion due to excessive Keepalive
messages.
The Keepalive timer and DeadTimer are initially negotiated through
the Keepalive TLV carried in the Hello Message.
4.2. Node Related Procedures
4.2.1. UP Resource Report
Once an S-CUSP session has been established between a CP and an UP.
The UP reports the information of the Boards and access side
interfaces on this UP to the CP as shown in Figure 5. Report messages
are unacknowledged and are assumed to be delivered because the
session runs over TCP.
The CP can use that information to activate/enable the Broadband
Access Service (BAS) functions (e.g., IPoE, PPPoE, etc.) on the
specified interfaces.
In addition, the UP resource report may trigger a UP warm-standby
process. In the case of warm-standby, a failure on an UP may trigger
the CP to start a warm-standby process, by moving the on-line
subscriber sessions to a standby UP and then direct the affected
subscribers to access the Internet through the standby UP.
UP CP
| |
| Report Board Status |
|------to CP via Ci----->|
| |
| Report Interface Status|
|------to CP via Ci----->|
| |
Figure 5: UP Board and Interface Report
Board status information is carried in the Board Status TLV (Section
7.10.2) and Interface status information is carried in Interface
Status TLV (Section 7.10.1). Both Board and Interface Status TLVs are
carried in the Report Message (Section 6.4).
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4.2.2. Update BAS Function on Access Interface
Once the CP collects the interface status of a UP, it will
activate/de-activate/modify the BAS functions on specified interfaces
through the Update_Request and Update_Response message (Section 6.2)
exchanges carrying the BAS Function TLV (Section 7.7).
UP CP
| |
| Update BAS function |
| Request |
|<-----on UP via Ci-------|
| |
| Update BAS function |
| Response |
|------on UP via Ci------>|
| |
Figure 6: Update BAS Function
4.2.3. Update Network Routing
The CP will allocate one or more address blocks to a UP. Each address
block contains a series of IP addresses. Those IP addresses will be
allocated to subscribers who are dialing up to the UP. To enable the
other nodes in the network to learn how to reach the subscribers, the
CP needs to install the routes on the UP and notify the UP to
advertise the routes to the network.
UP CP
| |
| Subscriber network route|
| update request |
|<------- via Ci----------|
| |
| Subscriber network route|
| update response |
|-------- via Ci--------->|
| |
Figure 7: Update Network Routing
The subscriber network routing update request and response are
achieved through the Update Request and Response Message exchanges by
carrying the IPv4/IPv6 Routing Information TLVs (Section 7.8).
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4.2.4. CGN Public IP Address Allocation
The following sequences describe the CGN address management related
procedures. Three independent procedures are defined, one each for
CGN address allocation request/response, CGN address renewal
request/response, and CGN address release request/response.
CGN address allocation/renew/release procedures are designed for the
case where the CGN function is running on the UP. The UP has to map
the subscriber private IP addresses to a public IP addresses, and
such mapping is performed by the UP locally when a subscriber dials-
up. That means the UP has to ask for public IPv4 address blocks for
CGN subscribers from the CP.
In addition, when a public IP address is allocated to a UP, there
will be a lease time (e.g., one day). Before the lease time expires,
the UP can ask for renewal of the IP address lease from the CP. It is
achieved by the exchange of the Addr_Renew_Req and Addr_Renew_Ack
messages.
If the public IP address will not be used anymore, the UP SHOULD
release the address by sending an Addr_Release_Req message to the CP.
If the CP wishes to withdraw addresses that it has previously leased
to a UP, it uses the same procedures as above. The "Oper" code in
the IPv4/IPv6 Routing TLV (see Section 7.1) determines whether the
request is an update or withdraw.
The relevant messages are defined in Section 6.5.
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UP CP
| |
| CGN Address Allocation |
| Request |
1.1|-------- via Ci--------->|
| CGN Address Allocation |
| Response |
1.2|<------- via Ci----------|
| |
| CGN Address Renew |
| Request |
2.1|-------- via Ci--------->|
| CGN Address Renew |
| Response |
2.2|<------- via Ci----------|
| |
| CGN Address Release |
| Request |
3.1|-------- via Ci--------->|
| CGN Address Release |
| Response |
3.3|<------- via Ci----------|
| |
Figure 8: CGN Public IP Address Allocation
4.2.5. Data Synchronization between the CP and UP
For a CU separated BNG, the UP will continue to function using the
state that has been installed in it even if the CP fails or the
session between the UP and CP fails.
Under some circumstances it is necessary to synchronize state between
the CP and UP, for example if a CP fails and the UP is switched to a
different CP.
Synchronization includes two directions. One direction is from UP to
CP; in that case, the synchronization information is mainly about the
board/interface status of the UP. The other direction is from CP to
UP; in that case, the subscriber sessions, subscriber network routes,
L2TP tunnels, etc. will be synchronized to the UP.
The synchronization is triggered by a Sync_Request message, to which
the receiver will (1) reply with a Sync_Begin message to notify the
requester that synchronization will begin, and (2) then start the
synchronization using the Sync_Data message. When synchronization
finished, a Sync_End message will be sent.
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The following figure shows the process of data synchronization
between a UP and a CP.
UP CP
| |
| Synchronization Request |
|<------- via Ci----------|
| |
| Synchronization Begin |
|-------- via Ci--------->|
| |
| Board/Interface Report |
|-------- via Ci--------->|
| |
| Synchronization End |
|-------- via Ci--------->|
| |
1) Synchronization from UP to CP
UP CP
| |
| Synchronization Request |
|-------- via Ci--------->|
| |
| Synchronization Begin |
|<-------- via Ci---------|
| |
| Synchronizes |
|Subscriber Session States|
| Network Route Entries |
|<------- via Ci----------|
| |
| Synchronization End |
|<-------- via Ci---------|
| |
2) Synchronization from CP to UP
Figure 9: Data Synchronization
4.3. Subscriber Session Related Procedures
A subscriber session consists of a set of forwarding states,
policies, and security rules that are applied to the subscriber. It
is used for forwarding subscriber traffic in a UP. To initialize a
session on a UP, a set of hardware resource have to be allocated
(e.g., NP, TCAM etc.) to a session.
Subscriber session related procedures include subscriber session
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create, update, delete, and statistics report. The following sub-
sections give a high level view of the procedures.
4.3.1. Create Subscriber Session
The below sequence describes the DHCP IPv4 dial-up process, it is an
example that shows how a subscriber session is created. (An example
for IPv6 appears in Section 5.1.2.)
RG UP CP AAA
| | | |
| Online Request| | |
1|-------------->| | |
| |Relay the Online Request| |
| 2|-----to CP via Si------>| Authentication|
| | | Req/Rep |
| | 3|<------------->|
| | Create subscriber | |
| | session Request | |
| 4|<--------via Ci---------| |
| | | |
| | Create subscriber | |
| | session Response | |
| 5|---------via Ci-------->| |
| | | |
| | | Accounting |
| | 6|<------------->|
| | | |
| | Send Online Response | |
| 7|<----to UP via Si-------| |
| | | |
|Online Response| | |
12|<--------------| | |
| | | |
Figure 10: Subscriber Session Create
The request starts from an Online Request message (step 1) from the
RG (for example, a DHCP Discovery packet). When the UP receives the
Online Request from the RG, it will tunnel the Online Request to the
CP through the Service Interface (Step 2). The Service Interface is
implemented by a tunneling technology.
When the CP receives the Online Request from the UP, it will send an
authentication request to the AAA server to authenticate and
authorize the subscriber (step 3). When a positive reply is received
from the AAA sever, the CP starts to create a subscriber session for
the request. Relevant resources (e.g., IP address, bandwidth, etc.)
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will be allocated to the subscriber, policies and security rules will
be generated for the subscriber Then the CP sends a session create
request to the UP through the Control Interface (Ci) (step 4), and a
response is expected from the UP to confirm the creation (step 5).
Finally, the CP will notify the AAA server to start accounting (step
6). At the same time, an Online Response message (for example, a
DHCP Ack packet) will be sent to the UP through the Si (step 7). And
the UP will forward the Online Response to the RG (step 8).
This completes the subscriber online process.
4.3.2. Update Subscriber Session
The following numbered sequence shows the process of subscriber
session update.
UP CP AAA
| | COA Request |
| 1|<--------------|
| Session update Request | |
2|<--------via Ci---------| |
| | |
| Session update Response| |
3|---------via Ci-------->| |
| | COA Response |
| 4|-------------->|
| | |
Figure 11: Subscriber Session Update
When a subscriber session has been created on a UP, there may be
requirements to update the session with new parameters (e.g.,
Bandwidth, QoS, policies, etc.).
This procedure is triggered by a Change of Authorization (COA)
request message sent by the AAA server. The CP will update the
session on the UP according to the new parameters through the Control
Interface.
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4.3.3. Delete Subscriber Session
The below call flow shows generally how S-CUPS deals with a
subscriber offline request.
RG UP CP
| | |
|Offline Request | |
1|--------------->| |
| | Relay the Offline |
| | Request |
| 2|------to CP via Si----->|
| | |
| | Send the Offline |
| | Response |
| 3|<-----to UP via Si------|
|Offline Response| |
4|<---------------| |
| | Session delete |
| | Request |
| |<--------via Ci---------|
| | Session delete |
| | Response |
| |---------via Ci-------->|
| | |
Figure 12: Subscriber Session Delete
Similar to the session creation process, when a UP receives an
offline request from a RG, it will tunnel the request to a CP through
the Si.
When the CP receives the offline request, it will withdraw/release
the resources (e.g., IP address, bandwidth) that have been allocated
to the subscriber. Then, it sends a reply to the UP through the
Service Interface and the UP will forward the reply to the RG. At
the same time, it will delete all the status of the session on the UP
through the Ci.
4.3.4. Subscriber Session Events Report
UP CP
| |
| Statistic/Detect report|
|---------via Ci-------->|
| |
Figure 13: Events Report
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When a session is created on an UP, the UP will periodically report
statistics information and detect results of the session to the CP.
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5. S-CUSP Call Flows
The subsections below give an overview of various "dial-up"
interactions over the Service Interface followed by an overview of
the setting of various information in the UP by the CP using S-CUSP
over the Control Interface.
S-CUSP messages are described in this document using Routing Backus
Naur Form (RBNF) as defined in [RFC5511].
5.1. IPoE
5.1.1. DHCPv4 Access
The following sequence shows detailed procedures for DHCPv4 access.
RG UP CP AAA
| | | |
| DHCP Discovery| | |
1|-------------->| | |
| |Relay the DHCP Discovery| |
| 2|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 3|<------------->|
| | | |
| | Send the DHCP Offer | |
| 4|<----to UP vis Si-------| |
| DHCP Offer | | |
5|<--------------| | |
| DHCP Request | | |
6|-------------->| | |
| | Relay the DHCP Request| |
| 7|-----to CP via Si------>| |
| | | |
| | Create subscriber | |
| | session Request | |
| 8|<--------via Ci---------| |
| | Create subscriber | |
| | session Response | |
| 9|---------via Ci-------->| |
| | | Accounting |
| | 10|<------------->|
| | | |
| | Send DHCP ACK | |
| 11|<----to UP via Si-------| |
| | | |
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| DHCP ACK | | |
12|<--------------| | |
| | | |
Figure 14: DHCPv4 Access
Step 8 and 9 are implemented by the S-CUSP protocol.
When a subscriber is authenticated and authorized by the AAA server,
the CP will create a subscriber session on the UP. This is achieved
by sending an Update_Request message to the UP.
The format of the Update_Request message is shown as follows using
RBNF:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
The UP will reply with an Update_Response message, the format of the
Update_Response message is as follows:
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
5.1.2. DHCPv6 Access
The following sequence shows detailed procedures for DHCPv6 access.
RG UP CP AAA
| | | |
| Solicit | | |
1|-------------->| | |
| | Relay the Solicit | |
| 2|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 3|<------------->|
| | | |
| | Send the Advertise | |
| 4|<----to UP vis Si-------| |
| Advertise | | |
5|<--------------| | |
| | | |
| Request | | |
6|-------------->| | |
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| | Relay the Request | |
| 7|-----to CP via Si------>| |
| | | |
| | | |
| | Create subscriber | |
| | session Request | |
| 8|<--------via Ci-------->| |
| | | |
| | Create subscriber | |
| | session Response | |
| 9|---------via Ci-------->| |
| | | |
| | | Accounting |
| | 10|<------------->|
| | | |
| | Send Reply | |
| 11|<----to UP via Si-------| |
| | | |
| Reply | | |
12|<--------------| | |
| | | |
Figure 15: DHCPv6 Access
Steps 1-7 are a standard DHCP IPv6 access process. The subscriber
creation is triggered by a DHCP IPv6 request message. When this
message is received, it means that the subscriber has passed the AAA
authentication and authorization. Then the CP will create a
subscriber session on the UP. This is achieved by sending an
Update_Request message to the UP (Step 8).
The format of the Update_Request message is as follows:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
The UP will reply with an Update_Response message (Step 9). The
format of the Update_Response message is as follows:
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
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5.1.3. IPv6 SLAAC Access
The following flow shows the IPv6 SLAAC access process.
RG UP CP AAA
| | | |
| RS | | |
1|-------------->| | |
| | Relay the Router | |
| | Solicit (RS) | |
| 2|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 3|<------------->|
| | | |
| | Create subscriber | |
| | session Request | |
| 4|<--------via Ci---------| |
| | | |
| | Create subscriber | |
| | session Response | |
| 5|---------via Ci-------->| |
| | | |
| | Send Router Advertise | |
| | (RA) | |
| 6|<----to UP vis Si-------| |
| RA | | |
7|<--------------| | |
| | | |
| NS | | |
8|-------------->| | |
| | Relay the Neighbor | |
| | Solicit (NS) | |
| 9|-----to CP via Si------>| |
| | | |
| | | Accounting |
| | 10|<------------->|
| | | |
| | Send a Neighbor | |
| | Advertise (NA) | |
| 11|<----to UP via Si-------| |
| | | |
| NA | | |
12|<--------------| | |
| | | |
Figure 16: IPv6 SLAAC Access
It starts with a Router Solicit (RS) request from an RG that is
tunneled to the CP by the UP. After the AAA authentication and
authorization, the CP will create a subscriber session on the UP.
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This is achieved by sending an Update_Request message to the UP (step
4).
The format of the Update_Request message is as follows:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
The UP will reply with an Update_Response message (step 5), the
format of the Update_Response message is as follows:
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.1.4. DHCPv6 + SLAAC Access
The following call flow shows the DHCP IPv6 and SLAAC access process.
RG UP CP AAA
| | | |
| RS | | |
1|-------------->| | |
| | Relay the Router | |
| | Solicit (RA) | |
| 2|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 3|<------------->|
| | | |
| | Create subscriber | |
| | session Request | |
| 4|<--------via Ci---------| |
| | | |
| | Create subscriber | |
| | session Response | |
| 5|---------via Ci-------->| |
| | | |
| | Send Router Advertise | |
| | (RA) | |
| 6|<----to UP vis Si-------| |
| RA | | |
7|<--------------| | |
| | | |
|DHCPv6 Solicit | | |
8|-------------->| | |
| | Relay DHCPv6 Solicit | |
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| 9|-----to CP via Si------>| |
| | | |
| | Update subscriber | |
| | session Request | |
| 10|<--------via Ci---------| |
| | | |
| | Update subscriber | |
| | session Response | |
| 11|---------via Ci-------->| |
| | | |
| | | Accounting |
| | 12|<------------->|
| | | |
| | Send DHCPv6 Reply | |
| 13|<----to UP via Si-------| |
| | | |
| DHCPv6 Reply | | |
14|<--------------| | |
| | | |
Figure 17: DHCPv6 + SLAAC Access
When a subscriber passes AAA authentication, the CP will create a
subscriber session on the UP. This is achieved by sending an
Update_Request message to the UP (step 4).
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
The UP will reply with an Update_Response message (step 5). The
format of the Update_Response is as follows:
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
After receiving a DHCPv6 Solicit, the CP will update the subscriber
session by sending an Update_Request message with new parameters to
the UP (Step 10).
The format of the Update_Request message is as follows:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
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The UP will reply with an Update_Response message (step 11). The
format of the Update_Response is as follows:
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.1.5. DHCP Dual Stack Access
The following sequence is a combination of DHCP IPv4 and DHCP IPv6
access processes.
RG UP CP AAA
| | | |
| DHCP Discovery| | |
1|-------------->| | |
| |Relay the DHCP Discovery| |
| 2|-----to CP via Si------>| AAA |
| | | Req/Resp |
| | 3|<------------->|
| | | |
| | Send the DHCP Offer | |
| 4|<----to UP vis Si-------| |
| DHCP Offer | | |
5|<--------------| | |
| DHCP Request | | |
6|-------------->| | |
| | Relay the DHCP Request| |
| 7|-----to CP via Si------>| |
| | | |
| | Create subscriber | |
| | session Request | |
| 8|<--------via Ci-------->| |
| | Create subscriber | |
| | session Response | |
| 9|---------via Ci-------->| |
| | | Accounting |
| | 10|<------------->|
| | Send DHCP ACK | |
| 11|<----to UP via Si-------| |
| | | |
| DHCP ACK | | |
12|<--------------| | |
| RS | | |
13|-------------->| | |
| | Relay the Router | |
| | Solicit (RA) | |
| 14|-----to CP via Si------>| AAA |
| | | Req/Rep |
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| | 15|<------------->|
| | | |
| | Create subscriber | |
| | session Request | |
| 16|<--------via Ci---------| |
| | Create subscriber | |
| | session Response | |
| 17|---------via Ci-------->| |
| | | |
| | Send Router Advertise | |
| | (RA) | |
| 18|<----to UP vis Si-------| |
| RA | | |
19|<--------------| | |
| | | |
|DHCPv6 Solicit | | |
20|-------------->| | |
| | Relay DHCPv6 Solicit | |
| 21|-----to CP via Si------>| |
| | | |
| | Update subscriber | |
| | session Request | |
| 22|<--------via Ci---------| |
| | Update subscriber | |
| | session Response | |
| 23|---------via Ci-------->| |
| | | Accounting |
| | 24|<------------->|
| | Send DHCPv6 Reply | |
| 25|<----to UP via Si-------| |
| DHCPv6 Reply | | |
26|<--------------| | |
| | | |
Figure 18: DHCP Dual Stack Access
The DHCP dual stack access includes three sets of Update_Request /
Update_Response exchanges to create/update DHCPv4/v6 subscriber
session.
1. Create DHCPv4 session (step 8 and 9)
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
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<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
2. Create DHCPv6 session (step 16 and 17)
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
3. Update DHCPv6 session (step 22 and 23)
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.1.6. L2 Static Subscriber Access
L2 static subscriber access processes are as follows:
RG UP CP AAA
| | | |
| | Static Subscriber | |
| | Detection Req. | |
| 1|<-----to UP via Ci------| |
| | Static Subscriber | |
| | Detection Rep. | |
| 2|------to UP via Ci----->| |
| ARP/ND(REQ) | | |
3.1|<--------------| | |
| ARP/ND(ACK) | | |
3.2|-------------->| | |
| | Relay the ARP/ND | |
| 3.3|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 3.4|<------------->|
| | Create subscriber | |
| | session Request | |
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| 3.5|<--------via Ci---------| |
| | Create subscriber | |
| | session Response | |
| 3.6|---------via Ci-------->| |
| | | |
| ARP/ND(REQ) | | |
4.1|-------------->| | |
| | Relay the ARP/ND | |
| 4.2|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 4.3|<------------->|
| | Create subscriber | |
| | session Request | |
| 4.4|<--------via Ci---------| |
| | Create subscriber | |
| | session Response | |
| 4.5|---------via Ci-------->| |
| ARP/ND(ACK) | | |
4.6|<--------------| | |
| | | |
| IP Traffic | | |
5.1|-------------->| | |
| | Relay the IP Traffic | |
| 5.2|-----to CP via Si------>| AAA |
| | | Req/Rep |
| | 5.3|<------------->|
| | Create subscriber | |
| | session Request | |
| 5.4|<--------via Ci-------->| |
| | Create subscriber | |
| | session Response | |
| 5.5|---------via Ci-------->| |
| | | |
| ARP/ND(REQ) | | |
5.6|<--------------| | |
| ARP/ND(ACK) | | |
5.7|-------------->| | |
| | | |
Figure 19: L2 Static Subscriber Access
For L2 static subscriber access, the process starts with a CP
installing a static subscriber detection list on an UP. The list
determines which subscribers will be detected. This is implemented
by exchanging Update_Request and Update_Response messages between CP
and UP. The format of the messages are as follows:
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<Update_Request Message> ::= <Common Header>
<IPv4 Static Subscriber Detect TLVs>
<IPv6 Static Subscriber Detect TLVs>
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
For L2 Static subscriber access, there are three ways to trigger the
access process:
1. Triggered by UP (3.1-3.6): This assumes that the UP knows the IP
address, the access interface, and VLAN of the RG. The UP will
actively trigger the access flow by sending an ARP/ND packet to
the RG. If the RG is online, it will reply with an ARP/ND to the
UP. The UP will tunnel the ARP/ND to the CP through the Si. The
CP then triggers the authentication process. If the
authentication result is positive. The CP will create a
corresponding subscriber session on the UP.
2. Triggered by RG ARP/ND (4.1-4.6): Most of the process is same as
option 1 (triggered by UP). The difference is that the RG will
actively send the ARP/ND to trigger the process.
3. Triggered by RG IP traffic (5.1-5.7): This is for the case where
the RG has the ARP/ND information, but the subscriber session on
the UP is lost (e.g., due to failure on the UP, or the UP
restarted). That means the RG may keep sending IP packets to the
UP. The packets will trigger the UP to start a new access
process.
From a subscriber session point of view, the procedures and the
message formats for the above three cases are the same, as follows:
IPv4 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
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<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.2. PPPoE
5.2.1. IPv4 PPPoE Access
The following figure shows the IPv4 PPPoE access call flow.
RG UP CP AAA
| | | |
| PPPoE Disc | PPPoE Disc | |
1|<------------->|<---------via Si------->| |
| | | |
| PPP LCP | PPP LCP | |
2|<------------->|<---------via Si------->| |
| | | AAA |
| PPP PAP/CHAP | PPP PAP/CHAP | Req/Rep |
3|<------------->|<---------via Si------->|<------------->|
| | | |
| PPP IPCP | PPP IPCP | |
4|<------------->|<---------via Si------->| |
| | | |
| | Create subscriber | |
| | session Request | |
| 5|<--------via Ci---------| |
| | | |
| | Create subscriber | |
| | session Response | |
| 6|---------via Ci-------->| |
| | | |
| | | Accounting |
| | 7|<------------->|
| | | |
Figure 20: IPv4 PPPoE Access
From the above sequence, step 1-4 are the standard PPPoE call flow.
The UP is responsible for redirecting the PPPoE control packets to
the CP or RG. The PPPoE control packets are transmitted between the
CP and UP through the Si.
After the PPPoE call flow, if the subscriber passed the AAA
authentication and authorization, the CP will create a corresponding
session on the UP through the Ci. The formats of the messages are as
follows:
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<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
5.2.2. IPv6 PPPoE Access
The following figure describes the IPv6 PPPoE access call flow.
RG UP CP AAA
| | | |
| PPPoE Disc | PPPoE Disc | |
1|<------------->|<--------via Si-------->| |
| | | |
| PPP LCP | PPP LCP | |
2|<------------->|<---------via Si------->| |
| | | AAA |
| PPP PAP/CHAP | PPP PAP/CHAP | Req/Rep |
3|<------------->|<---------via Si------->|<------------->|
| | | |
| PPP IP6CP | PPP IP6CP | |
4|<------------->|<---------via Si------->| |
| | | |
| | Create subscriber | |
| | session Request | |
| 5|<--------via Ci---------| |
| | | |
| | Create subscriber | |
| | session Response | |
| 6|---------via Ci-------->| |
| | | |
| ND Negotiation| ND Negotiation | |
7|<------------->|<---------via Si------->| |
| | | |
| | Update subscriber | |
| | session Request | |
| 8|<--------via Ci---------| |
| | | |
| | Update subscriber | |
| | session Response | |
| 9|---------via Ci-------->| |
| | | |
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| | | Accounting |
| | 10|<------------->|
| | | |
| DHCPv6 | DHCPv6 | |
| Negotiation | Negotiation | |
7'|<------------->|<---------via Si------->| |
| | | |
| | Update subscriber | |
| | session Request | |
| 8'|<---------via Ci--------| |
| | | |
| | Update subscriber | |
| | session Response | |
| 9'|---------via Ci-------->| |
| | | |
| | | Accounting |
| | 10'|<------------->|
| | | |
Figure 21: IPv6 PPPoE Access
From the above sequence, steps 1-4 are the standard PPPoE call flow.
The UP is responsible for redirecting the PPPoE control packets to
the CP or RG. The PPPoE control packets are transmitted between the
CP and UP through the Si.
After the PPPoE call flow, if the subscriber passed the AAA
authentication and authorization, the CP will create a corresponding
session on the UP through the Ci. The formats of the messages are as
follows:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
Then, the RG will initialize a ND/DHCPv6 negotiation process with the
CP (see step 7 and 7'), after that, it will trigger an update (8-9,
8'-9') to the subscriber session. The formats of the update messages
are as follows:
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<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.2.3. PPPoE Dual Stack Access
The following figure shows a combination of IPv4 and IPv6 PPPoE
access call flow.
RG UP CP AAA
| | | |
|PPPoE Discovery| PPPoE Discovery | |
1|<------------->|<---------via Si------->| |
| | | |
| PPP LCP | PPP LCP | |
2|<------------->|<---------via Si------->| |
| | | AAA |
| PPP PAP/CHAP | PPP PAP/CHAP | Req/Rep |
3|<------------->|<---------via Si------->|<------------->|
| | | |
| PPP IPCP | PPP IPCP | |
4|<------------->|<---------via Si------->| |
| | | |
| | Create v4 subscriber | |
| | session Request | |
| 5|<--------via Ci---------| |
| | Create v4 subscriber | |
| | session Response | |
| 6|---------via Ci-------->| |
| | | Accounting |
| | 7|<------------->|
| PPP IP6CP | PPP IP6CP | |
4'|<------------->|<---------via Si------->| |
| | | |
| | Create V6 subscriber | |
| | session Request | |
| 5'|<--------via Ci---------| |
| | Create v6 subscriber | |
| | session Response | |
| 6'|---------via Ci-------->| |
| | | |
| ND Negotiation| ND Negotiation | |
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8|<------------->|<---------via Si------->| |
| | | |
| | Update v6 subscriber | |
| | session Request | |
| 9|<---------via Ci--------| |
| | Update v6 subscriber | |
| | session Response | |
| 10|---------via Ci-------->| |
| | | Accounting |
| | 7'|<------------->|
| DHCPv6 | DHCPv6 | |
| Negotiation | Negotiation | |
8'|<------------->|<---------via Si------->| |
| | | |
| | Update v6 subscriber | |
| | session Request | |
| 9'|<--------via Ci---------| |
| | | |
| | Update v6 subscriber | |
| | session Response | |
| 10'|---------via Ci-------->| |
| | | |
| | | Accounting |
| | 7"|<------------->|
| | | |
Figure 22: PPPoE Dual Stack Access
PPPoE dual stack is a combination of IPv4 PPPoE and IPv6 PPPoE
access. The process is as above. The formats of the messages are as
follows:
1. Create an IPv4 PPPoE subscriber session (5-6)
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
2. Create an IPv6 PPPoE subscriber session (5'-6')
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
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<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
3. Update the IPv6 PPPoE subscriber session (9-10, 9'-10')
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.3. WLAN Access
The following figure shows the WLAN access call flow.
RG UP CP AAA WEB Server
| | | | |
| DHCP | | | |
| Discovery | | | |
1|------------>| | | |
| | DHCP | | |
| | Discovery | | |
| 2|-----via Si---->| AAA | |
| | DHCP Offer |<-------->| |
| 3|<----via Si-----| | |
| DHCP Offer | | | |
4|<------------| | | |
| DHCP | | | |
| Request | | | |
5|------------>| | | |
| | DHCP Request | | |
| 6|-----via Si---->| | |
| | | | |
| | Create session | | |
| | Request | | |
| 7|<----via Ci-----| | |
| | Create session | | |
| | Response | | |
| 8|----via Ci----->| | |
| | | | |
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| | DHCP ACK | | |
| 9|<----via Si-----| | |
| | | | |
| DHCP ACK | | | |
10|<------------| | | |
| | | | |
| Subscriber | | | |
| HTTP Traffic| | | |
11|------------>|--> | | |
| | | WEB URL | | |
| Traffic | | Redirect | | |
| Redirection | | | | |
12|<------------|<-+ | | |
| | | |
| |
13|-----------------Redirect to Web server------------->|
| |
14|<----------------Push HTTP log-in page---------------|
| |
15|-----------------User Authentication---------------->|
| |
| | | Portal Interchange |
| | 16|<-------------------->|
| | | |
| | | AAA | |
| | | Req/Rep | |
| | 17|<-------->| |
| | | | |
| | Update session | | |
| | Request | | |
| 18|<----via Ci-----| | |
| | | | |
| | Update session | | |
| | Response | | |
| 19|-----via Ci---->| | |
| | | | |
Figure 23: WLAN Access
WLAN access starts with the DHCP dial-up process (steps 1-6), after
that the CP will create a subscriber session on the UP (steps 7-8).
The formats of the session creation messages are as follows:
IPv4 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
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<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
After step 10, the RG will be allocated an IP address and its first
HTTP packet will be redirected to a WEB server for subscriber
authentication (steps 11-17). After the WEB authentication, if the
result is positive, the CP will update the subscriber session by
using the following message exchanges:
IPv4 Case: <Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case: <Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.4. L2TP
5.4.1. L2TP LAC Access
RG UP(LAC) CP(LAC) AAA LNS
| | | | |
| PPPoE | PPPoE | | |
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| Discovery | Discovery | | |
1|<---------->|<---via Si--->| | |
| | | | |
| PPP LCP | PPP LCP | | |
2|<---------->|<---via Si--->| | |
| | | AAA | |
|PPP PAP/CHAP| PPP PAP/CHAP | Req/Rep| |
3|<---------->|<---via Si--->|<------>| |
| | | | |
| PPP IPCP | PPP IPCP | | |
4|<---------->|<---via Si--->| | |
| | | | |
| | L2TP tunnel | | |
| | negotiation | | |
| | SCCRQ/ | | |
| | SCCRP/ | | |
| | SCCCN | | |
| 5|<---via Si--->| | |
| | /\ |
| | || forward |
| | \/ |
| |<-----------via routing---------->|
| | |
| | L2TP session | | |
| | negotiation | | |
| | ICRQ/ | | |
| | ICRP/ | | |
| | ICCN | | |
| 6|<---via Si--->| | |
| | /\ |
| | || forward |
| | \/ |
| |<-----------via routing---------->|
| | |
| | Create | | |
| | subscriber | | |
| | session | | |
| | Request | | |
| 7|<---via Ci----| | |
| | | | |
| | Create | | |
| | subscriber | | |
| | session | | |
| | Response | | |
| 8|----via Ci--->| | |
| | | | |
| |
| PAP/CHAP (Triggered by LNS) |
9|<-----------------via routing?---------------->|
| |
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Figure 24: L2TP-LAC Access
Steps 1-4 are a standard PPPoE access process. After that the LAC-CP
starts to negotiate an L2TP session and tunnel with the LNS. After
the negotiation, the CP will create an L2TP LAC subscriber session on
the UP through the following messages:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<L2TP-LAC Subscriber TLV>
<L2TP-LAC Tunnel TLV>
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.4.2. L2TP LNS IPv4 Access
RG LAC UP(LNS) AAA CP(LNS)
| | | | |
| PPPoE | | | |
| Discovery | | | |
1|<---------->| | | |
| | | | |
| PPP LCP | | | |
2|<---------->| | |
| | AAA | |
|PPP PAP/CHAP| Req/Rep | |
3|<---------->|<--------------------->| |
| | |
| | |
| | L2TP tunnel | L2TP tunnel |
| | negotiation | negotiation |
| | SCCRQ/ | SCCRQ/ |
| | SCCRP/ | SCCRP/ |
| | SCCCN | SCCCN |
| 4|<------------>|<------via Si----->|
| | | |
| | L2TP session | L2TP session |
| | negotiation | negotiation |
| | ICRQ/ | ICRQ/ |
| | ICRP/ | ICRP/ |
| | ICCN | ICCN |
| 5|<------------>|<------via Si----->|
| | | |
| | | Create |
| | | subscriber |
| | | session |
| | | Request |
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| | 6|<-----via Ci-------|
| | | Create |
| | | subscriber |
| | | session |
| | | Response |
| | 7|------via Ci------>|
| |
| PAP/CHAP (Triggered by LNS) |
8|<--------------------------------------------->|
| |
| | | | AAA |
| | | | Req/Rep |
| | | 9|<-------->|
| | | |
| |
| PPP IPCP |
10|<--------------------------------------------->|
| |
| | | Update |
| | | subscriber |
| | | session |
| | | Request |
| | 11|<-----via Ci-------|
| | | Update |
| | | subscriber |
| | | session |
| | | Response |
| | 12|------via Ci------>|
| | | |
Figure 25: IPv4 L2TP-LNS Access
In this case, the BNG is running as an LNS and separated into LNS-CP
and LNS-UP. Steps 1-5 finish the normal L2TP dial-up process. When
the L2TP session and tunnel negotiations are finished, the LNS-CP
will create an L2TP LNS subscriber session on the LNS-UP. The format
of messages are as follows:
<Update_Request Message> ::= <Common Header>
<L2TP-LNS Subscriber TLV>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
<L2TP-LNS Tunnel TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
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After that, the LNS-CP will trigger an AAA authentication. If the
authentication result is positive, a PPP IPCP process will follow,
then the CP will update the session with the following message
exchanges:
<Update_Request Message> ::= <Common Header>
<L2TP-LNS Subscriber TLV>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
<L2TP-LNS Tunnel TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
5.4.3. L2TP LNS IPv6 Access
RG LAC UP(LNS) AAA CP(LNS)
| | | | |
| PPPoE | | | |
| Discovery | | | |
1|<---------->| | | |
| | | | |
| PPP LCP | | | |
2|<---------->| | |
| | AAA | |
|PPP PAP/CHAP| Req/Rep | |
3|<---------->|<--------------------->| |
| | |
| | |
| | L2TP tunnel | L2TP tunnel |
| | negotiation | negotiation |
| | SCCRQ/ | SCCRQ/ |
| | SCCRP/ | SCCRP/ |
| | SCCCN | SCCCN |
| 4|<------------>|<------via Si----->|
| | | |
| | L2TP session | L2TP session |
| | negotiation | negotiation |
| | ICRQ/ | ICRQ/ |
| | ICRP/ | ICRP/ |
| | ICCN | ICCN |
| 5|<------------>|<------via Si----->|
| | | |
| | | Create |
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| | | subscriber |
| | | session |
| | | Request |
| | 6|<-----via Ci-------|
| | | Create |
| | | subscriber |
| | | session |
| | | Response |
| | 7|------via Ci------>|
| |
| PAP/CHAP (Triggered by LNS) |
8|<--------------------------------------------->|
| |
| | | | AAA |
| | | | Req/Rep |
| | | 9|<-------->|
| | | | |
| |
| PPP IP6CP |
10|<--------------------------------------------->|
| |
| | | Update |
| | | subscriber |
| | | session |
| | | Request |
| | 11|<-----via Ci-------|
| | | Update |
| | | subscriber |
| | | session |
| | | Response |
| | 12|------via Ci------>|
| | | |
| | |
| ND negotiation | ND negotiation |
13|<------------------------->|<-----via Si------>|
| | |
| | | Update |
| | | subscriber |
| | | session |
| | | Request |
| | 14|<-----via Ci-------|
| | | Update |
| | | subscriber |
| | | session |
| | | Response |
| | 15|------via Ci------>|
| | | |
Figure 26: L2TP-LNS IPv6 Access
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Steps 1-12 are the same as L2TP and LNS IPv4 Access. Steps 1-5
finish the normal L2TP dial-up process. When the L2TP session and
tunnel negotiations are finished, the LNS-CP will create an L2TP LNS
subscriber session on the LNS-UP. The format of the messages is as
follows:
<Update_Request Message> ::= <Common Header>
<L2TP-LNS Subscriber TLV>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
<L2TP-LNS Tunnel TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
After that, the LNS-CP will trigger a AAA authentication. If the
authentication result is positive, a PPP IP6CP process will follow,
then the CP will update the session with the following message
exchanges:
<Update_Request Message> ::= <Common Header>
<L2TP-LNS Subscriber TLV>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
<L2TP-LNS Tunnel TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
Then, an ND negotiation will be triggered by the RG. After the ND
negotiation, the CP will update the session with the following
message exchanges:
<Update_Request Message> ::= <Common Header>
<L2TP-LAC Subscriber TLV>
<Basic Subscriber TLV>
<PPP Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
<L2TP-LNS Tunnel TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
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5.5. CGN (Carrier Grade NAT)
RG UP CP AAA
| | | |
| | Public Address Block | |
| | Allocation Request | |
| 1|<--------via Ci-------->| |
| | Public Address Block | |
| | Allocation Reply | |
| 2|---------via Ci-------->| |
| | | |
| Subscriber | | |
| access request| Subscriber | |
3|-------------->| access request | |
| 4|----------via Si------->| |
| | | AAA |
| | Subscriber | Req/Rep |
| Subscriber | access reply 5|<------------->|
| access reply 6|<---------via Si--------| |
7|<--------------| | |
| | | |
| | Create subscriber | |
| | session Request | |
| 8|<--------via Ci---------| |
| | | |
| | Create subscriber | |
| | session Response | |
| | (with NAT information) | |
| 9|---------via Ci-------->| |
| | | |
| | | Accounting |
| | | with source |
| | | information |
| | 10|<------------->|
| | | Public IP + |
| | | Port range |
| | | to Private IP|
| | | mapping |
| | | |
Figure 27: CGN Access
The first steps allocate one or more CGN address blocks to the UP
(steps 1-2). This is achieved by the following message exchanges
between CP and UP.
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<Addr_Allocation_Req Message> ::= <Common Header>
<Request Address Allocation TLV>
<Addr_Allocation_Ack Message> ::= <Common Header>
<Address Assignment Response TLV>
Steps 3-9 show the general dial-up process in the case of CGN mode.
The specific processes (e.g., IPoE, PPPoE, L2TP, etc.) are defined in
above sections.
If a subscriber is a CGN subscriber, once the subscriber session is
created/updated, the UP will report the NAT information to the CP.
This is achieved by carrying the "Subscriber CGN Port Range TLV" in
the Update_Response message.
5.6. L3 Leased Line Access
5.6.1. Web Authentication
RG UP CP AAA WEB Server
| | | | |
| User | | | |
| traffic | | | |
1|------------>| | | |
| | User | | |
| | traffic | | |
| 2|-----via Si---->| AAA | |
| | | Req/Rep | |
| | 3|<-------->| |
| | Create session | | |
| | Request | | |
| 4|<----via Ci-----| | |
| | | | |
| | Create session | | |
| | Response | | |
| 5|----via Ci----->| | |
| HTTP | | | |
| traffic | | | |
6|------------>| | | |
| | | | |
| Redirect to | | | |
| Web URL | | | |
7|<------------| | | |
| | | | |
| |
8|-----------------Redirected to Web server----------->|
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| |
9|<----------------Push HTTP Log-in page---------------|
| |
10|-----------------User Authentication---------------->|
| |
| | | Portal Interchange |
| | 11|<-------------------->|
| | | |
| | | AAA | |
| | | Req/Rep | |
| | 12|<-------->| |
| | | | |
| | | | |
| | Update session | | |
| | Request | | |
| 13|<----via Ci-----| | |
| | | | |
| | Update session | | |
| | Response | | |
| 14|----via Ci----->| | |
| | | | |
Figure 28: Web Authentication based L3 Leased Line Access
In this case, IP traffic from the RG will trigger the CP to
authenticate the RG by checking the source IP and the exchanges with
the AAA server. Once the RG passed the authentication, the CP will
create a corresponding subscriber session on the UP through the
following message exchanges:
IPv4 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
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Then, the HTTP traffic from the RG will be redirected to a WEB server
to finish the WEB authentication. Once the WEB authentication is
passed, the CP will trigger another AAA authentication. After the
AAA authentication, the CP will update the session with the following
message exchanges:
IPv4 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.6.2. User Traffic Trigger
RG UP CP AAA
| | | |
| | L3 access | |
| | control list | |
| 1|<----via Ci-----| |
| User | | |
| traffic | | |
2|------------>| | |
| | User | |
| | traffic | |
| 3|-----via Si---->| |
| | | AAA |
| | | Req/Rep |
| | 4|<-------->|
| | | |
| | Create session | |
| | Request | |
| 5|<----via Ci-----| |
| | Create session | |
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| | Response | |
| 6|----via Ci----->| |
| | | |
Figure 29: User Traffic Triggered L3 Leased Line Access
In this user traffic triggered case, the CP must install an access
control list on the UP, which is used by the UP to determine whether
an RG is legal or not. If the traffic is from a legal RG, it will be
redirected to the CP though the Si. The CP will trigger a AAA
interchange with the AAA server. After that, the CP will create a
corresponding subscriber session on the UP with the following message
exchanges:
IPv4 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case:
<Update_Request Message> ::= <Common Header>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
5.7. Multicast Access
RG UP CP AAA
| | | |
| User access | User access | AAA |
| request | request | Req/Rep |
1|<----------->|<----via Si---->|<-------->|
| | User | |
| | | |
| | | |
| | Create session | |
| | Request | |
| 2|<----via Ci---->| |
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| | | |
| | Create session | |
| | Response | |
| 3|----via Ci----->| |
| | | |
| Multicast | | |
| negotiation | | |
4|<----------->| | |
| | | |
Figure 30: Multicast Access
Multicast access starts with an user access request from the RG. The
request will be redirected to the CP by the Si. A follow-up AAA
interchange between the CP and the AAA server will be triggered.
After the authentication, the CP will create a multicast subscriber
session on the UP through the following messages:
IPv4 Case:
<Update_Request Message> ::= <Common Header>
<Multicast Group Information TLV>
<Basic Subscriber TLV>
<IPv4 Subscriber TLV>
<IPv4 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
[<Subscriber CGN Port Range TLV>]
IPv6 Case:
<Update_Request Message> ::= <Common Header>
<Multicast Group Information TLV>
<Basic Subscriber TLV>
<IPv6 Subscriber TLV>
<IPv6 Routing TLV>
[<Subscriber Policy TLV>]
<Update_Response Message> ::= <Common Header>
<Update Response TLV>
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6. S-CUSP Message Formats
An S-CUSP message consists of a common header followed by a variable-
length body consisting entirely of TLVs. Receiving an S-CUSP message
with an unknown message type or missing mandatory TLV MUST trigger an
Error message (see Section 6.7) or a response message with an Error
Information TLV (see Section 7.6).
Conversely, if a TLV is optional, the TLV may or may not be present.
Optional TLVs are indicated in the message formats shown in this
document by being enclosed in square brackets.
This section specifies the format of the common S-CUSP message header
and lists the defined messages.
Network byte order is used for all multi-byte fields.
6.1. Common Message Header
S-CUSP Common Message Header:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ver | Resv | Message-Type | Message-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Transaction-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6.1: S-CUSP Message Common Header
o Ver (4 bits): The major version of the protocol. This document
specifies version 1. Different major versions of the protocol
may have significantly different message structure and format
except that the Ver field will always be in the same place at
the beginning of each message. A successful S-CUSP session
depends on the CP and the UP both using the same major version
of the protocol.
o Resv (4 bits): Reserved. MUST be sent as zero and ignored on
receipt.
o Message-Type (8 bits): The set of message types specified in
this document is listed in Section 9.1.
o Message-Length (16 bits): Total length of the S-CUSP message
including the common header, expressed in number of bytes as an
unsigned integer.
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o Transaction ID (16 bits): This field is used to identify
requests. It is echoed back in any corresponding ACK / response
/ Error message. It is RECOMMENDED that a monotonically
increasing value be used in successive message and that value
wrap back to zero after 0xFFFF. The contents of this field is
an opaque value that the receiver MUST NOT use for any purpose
except to echo back in a corresponding response and,
optionally, for logging.
6.2. Control Messages
This document defines the following control messages:
Type Name Notes and TLVs that can be carried
---- ---- ------------------------------------
1 Hello Hello TLV, Keep-Alive TLV.
2 Keepalive A common header with the Keepalive message
type.
3 Sync_Request Synchronization request.
4 Sync_Begin Synchronization starts.
5 Sync_Data Synchronization data: TLVs specified in
Section 5.
6 Sync_End End synchronization.
7 Update_Request TLVs specified in Sections 7.6-7.9.
8 Update_Response TLVs specified in Sections 7.6-7.9.
6.2.1. Hello Message
Hello message is used for S-CUSP session establishment and version
negotiation. The detail of S-CUSP session establishment and version
negotiation can be found in Section 4.1.1.
The format of Hello message is as follows:
<Hello Message> ::= <Common Header>
<Hello TLV>
<Keepalive TLV>
[<Error Information TLV>]
The return code and negotiation result will be carried in the Error
Information TLV. They are listed as follows:
0: Success, version negotiation success.
1: Failure, malformed message received.
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2: One or more of the TLVs was not understood.
1001: The version negotiation fails. The S-CUSP session
establishment phase fails.
1002: The keepalive negotiation fails. The S-CUSP session
establishment phase fails.
1003: The establishment timer expires. session establishment
phase fails.
6.2.2. Keepalive Message
The Keepalive message is periodically sent by each end of an S-CUSP
session. It is used to detect whether the peer end is still alive.
The Keepalive procedures are defined Section 4.1.2.
The format of the Keepalive message is as follows:
<Keepalive Message> ::= <Common Header>
6.2.3. Sync_Request Message
The Sync_Request message is used to request synchronization from an
S-CUSP peer. Both CP and UP can request their peer to synchronize
data.
The format of the Sync_Request message is as follows:
<Sync_Request Message> ::= <Common Header>
A Sync_Request message may result in a Sync_Begin message from its
peer. The Sync_Begin message is defined in Section 6.2.4.
6.2.4. Sync_Begin Message
The Sync_Begin message is a reply to a Sync_Request message. It is
used to notify the synchronization requester whether the
synchronization can be started.
The format of Sync_Begin message is as follows:
<Sync_Begin Message> ::= <Common Header>
<Error Information TLV>
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The return codes are carried in the Error Information TLV. The codes
are listed below:
0: Success, be ready to synchronize.
1: Failure, malformed message received.
2: One or more of the TLVs was not understood.
2001: Synch-NoReady. The data to be synchronized is not ready.
2002: Synch-Unsupport. The data synchronization is not supported.
6.2.5. Sync_Data Message
The Sync_Data message is used to send data being synchronized between
the CP and UP. The Sync_Data message has the same function and
format as the Update_Request message. The difference is that there
is no ACK for a Sync_Data message. An error caused by the Sync_Data
message will result in a Sync_End message.
There are two scenarios:
Synchronization from UP to CP: Synchronize the resource data to
CP.
<Sync_Data Message> ::= <Common Header>
[<Resource Reporting TLVs>]
Synchronization from CP to UP: Synchronize all subscriber sessions
to UP. As for which TLVs should be carried, it depends on the
specific session data to be synchronized. This is equivalent to
create the specific session. Refer to Section 5 to see more
details.
<Sync_Data Message> ::= <Common Header>
[<User Routing TLVs>]
[<User Information TLVs>]
[<L2TP Subscriber TLVs>]
[<Subscriber CGN Port Range TLV>]
[<Subscriber Policy TLV>]
6.2.6. Sync_End Message
The Sync_End message is used to indicate the end of a synchronization
process. The format of a Sync_End message is as follows:
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<Sync_End Message> ::= <Common Header>
<Error Information TLV>
The return/error codes are listed as follows:
0: Success, synchronization finished.
1: Failure, malformed message received.
2: One or more of the TLVs was not understood.
6.2.7. Update_Request Message
The Update_Request message is a multi-task message, it can be used to
create, update, and delete subscriber sessions on a UP.
For session operations, the specific operation is controlled by the
"Oper" field of the carried TLVs. As defined in Section 7.1, the
"Oper" can be set to either "update" or "delete" when a TLV is
carried in an Update_Request message.
When the "Oper" set to update, it means to create or update a
subscriber session, if the "Oper" set to delete, it indicates to
delete a corresponding session on an UP.
The format of Update_Request message is as follows:
<Update_Request Message> ::= <Common Header>
[<User Routing TLVs>]
[<User Information TLVs>]
[<L2TP Subscriber TLVs>]
[<Subscriber CGN Port Range TLV>]
[<Subscriber Policy TLV>]
Each Update_Request message will result in an Update_Response message
that is defined in Section 6.2.8.
6.2.8. Update_Response Message
The Update_Response message is a response to an Update_Request
message. It is used to confirm the update request (or reject it in
the case of an error). The format of an Update_Response message is
as follows:
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<Update_Response Message> ::= <Common Header>
[<Subscriber CGN Port Range TLV>]
<Error Information TLV>
The return/error codes are carried in the Error Information TLV.
They are listed as follows:
0: Success.
1: Failure, malformed message received.
2: One or more of the TLVs was not understood.
3001(Pool-Mismatch): The corresponding address pool cannot be
found.
3002 (Pool-Full): The address pool is fully allocated and no
address segment is available.
3003 (Subnet-Mismatch): The address pool subnet cannot be found.
3004 (Subnet-Conflict): Subnets in the address pool have been
classified into other clients.
4001 (Update-Fail-No-Res): The forwarding table fails to be
delivered because the forwarding resources are insufficient.
4002 (QoS-Update-Success): The QoS policy takes effect.
4003 (QoS-Update-Sq-Fail): Failed to process the queue in the QoS
policy.
4004 (QoS-Update-CAR-Fail): Processing of the CAR in the QoS
policy fails.
4005 (Statistic-Fail-No-Res): Statistics processing failed due to
insufficient statistics resources.
6.3. Event Message
The Event message is used to report subscriber session traffic
statistics and detection information. The format of Event message is
as follows:
<Event Message> ::= <Common Header>
[<User Traffic Statistics Report TLV>]
[<User Detection Result Report TLV>]
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6.4. Report Message
The Report message is used to report board and interface status on a
UP. The format of Report message is as follows:
<Report Message> ::= <Common Header>
[<Board Status TLVs>]
[<Interface Status TLVs>]
6.5. CGN Messages
This document defines the following resource allocation messages:
Type Message Name TLV that is carried
---- ------------------- ------------------------
200 Addr_Allocation_Req Address Allocation Request
201 Addr_Allocation_Ack Address Allocation Response
202 Addr_Renew_Req Address Renewal Request
203 Addr_Renew_Ack Address Renewal Response
204 Addr_Release_Req Address Release Request
205 Addr_Release_Ack Address Release Response
6.5.1. Addr_Allocation_Req Message
The Addr_Allocation_Req message is used to request CGN address
allocation. The format of Addr_Allocation_Req message is as follows:
<Addr_Allocation_Req Message> ::= <Common Header>
<Address Allocation Request TLV>
6.5.2. Addr_Allocation_Ack Message
The Addr_Allocation_Ack message is a response to an
Addr_Allocation_Req message. The format of Addr_Allocation_Ack
message is as follows:
<Addr_Allocation_Ack Message> ::= <Common Header>
<Address Allocation Response TLV>
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6.5.3. Addr_Renew_Req Message
The Addr_Renew_Req message is used to request address renewal. The
format of Addr_Renew_Req message is as follows:
<Addr_Renew_Req Message> ::= <Common Header>
<Address Renewal Request TLV>
6.5.4. Addr_Renew_Ack Message
The Addr_Renew_Ack message is a response to an Addr_Renew_Req
message. The format of Addr_Renew_Req message is as follows:
<Addr_Renew_Ack Message> ::= <Common Header>
<Address Renewal Response TLV>
6.5.5. Addr_Release_Req Message
The Addr_Release_Req message is used to request address release. The
format of Addr_Release_Req message is as follows:
<Addr_Release_Req Message> ::= <Common Header>
<Address Release Request TLV>
6.5.6. Addr_Release_Ack Message
The Addr_Release_Ack message is a response to an Addr_Release_Req
message. The format of Addr_Release_Ack message is as follows:
<Addr_Release_Ack Message> ::= <Common Header>
<Address Release Response TLV>
6.6. Vendor Message
The Vendor message is, in conjunction with the vendor TLV and vendor
sub-TLV, can be used by vendors to extend the S-CUSP protocol. It's
message type is 11. If the receiver does not recognize the message,
an Error message will be returned to the sender.
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The format of the Vendor message is as follows:
<Vendor Message> ::= <Common Header>
<Vendor TLV>
[<any other TLVs as specified by the vendor>]
6.7 Error Message
The Error message is defined to return some critical error
information to the sender. If a receiver does not know the message
type of a received message, it MUST return an Error message to the
sender.
The format of the Error message is as below:
<Error Message> ::= <Common Header>
<Error Information TLV>
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7. S-CUSP TLVs and Sub-TLVs
This section specifies the following:
o the format of the TLVs that appear in S-CUSP messages,
o the format of the sub-TLVs that appear within the values of some
TLVs, and
o the format of some basic data fields that appear within TLVs or
sub-TLVs.
See Section 9 for a list of all defined TLVs and sub-TLVs.
7.1. Common TLV Header
S-CUSP messages consist of the common header specified in Section 6.1
followed by TLVs formatted as specified in this section.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Oper | TLV-Type | TLV-Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Value ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 32: Common TLV Header
o Oper (4 bits): For Message-Types that indicate an operation on a
data set, the Oper field is interpreted as Update, Delete, or
Reserved as specified in Section 9.3. For all other Message-Types,
the Oper field MUST be sent as zero and ignored on receipt.
o TLV-Type (12 bits): The Type of a TLV, that is the meaning and
format of the Value part, are determined by the TLV-Type of the
TLV. See Section 9.2.
o TLV-Length (2 bytes): The length of the Value portion of the TLV
in bytes as an unsigned integer.
o Value (variable length): This is the value portion of the TLV
whose size is given by TLV-Length. The value portion consists of
fields, frequently using one of the basic data field types (see
Section 7.2) and sub-TLVs (see Section 7.3).
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7.2. Basic Data Fields
This section specifies the binary format of several standard basic
data fields that are used within other data structures in this
specification.
o STRING: 0 to 255 octets. Will be encoded as a sub-TLV (see Section
7.3) to provide the length. The use of this data type in S-CUSP is
to provide convenient labels for use by network operators in
configuring and debugging their networks and interpreting S-CUSP
messages. These labels will not normally be seen by subscribers.
They are normally interpreted as ASCII [RFC20].
o MAC-Addr: 6 octets. Ethernet MAC Address [RFC7042].
o IPv4-Address: 8 octets. 4 octets of the IPv4 address value
followed by a 4 octet address mask in the format XXX.XXX.XXX.XXX.
o IPv6-Address: 20 octets. 16 octets of IPv6 address followed by a 4
octet integer n in the range of 0 to 128 which gives the address
mask as the one's complement of 2**(128-n) - 1.
o VLAN ID: 2 octets. As follows [802.1Q]:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PRI |D| VLAN-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
PRI: Priority. Default value 7.
D: Drop Eligibility Indicator (DEI). Default value 0.
VLAN-ID: Unsigned integer in the range 1-4094. (0 and 4095 are
not valid VLAN IDs [802.1Q].)
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7.3. Sub-TLV Format and Sub-TLVs
In some cases, the Value portion of a TLV, as specified above, can
contain one or more Sub-TLVs formatted as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...
Figure 33: Sub-TLV Header
o Type (2 bytes): The Type of a Sub-TLV, that is the meaning and
format of the Value part, are determined by the Type of the
TLV. Sub-TLV Types numbers have the same meaning regardless of
the TLV Type of the TLV within which the sub-TLV occurs. See
Section 9.4.
o Length (2 bytes): The length of the Value portion of the sub-
TLV in bytes as an unsigned integer.
o Value (variable length): This is the value portion of the sub-
TLV whose size is given by Length.
The sub-TLVs currently specified are defined in the following
subsections.
7.3.1. Name sub-TLVs
This document defines the following name sub-TLVs that are used to
carry the name of the corresponding object. The length of each of
these sub-TLV is variable from 1 to 255 octets. The value is of type
STRING padded with zeros octets to 4-octet alignment.
Type Sub-TLV Name Meaning
----- -------------------- -------------------
1 VRF-Name The name of a VRF
2 Ingress-QoS-Profile The name of an ingress QoS profile
3 Egress-QoS-Profile The name of an egress QoS profile
4 User-ACL-Policy The name of an ACL policy
5 Multicast-ProfileV4 The name of an IPv4 multicast profile
6 Multicast-ProfileV6 The name of an IPv6 multicast profile
7 NAT-Instance The name of a NAT instance
8 Pool-Name The name of an address pool
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7.3.2. Ingress-CAR sub-TLV
The Ingress-CAR sub-TLV indicates the authorized upstream Committed
Access Rate (CAR) parameters. The sub-TLV type of the Ingress-CAR
sub-TLV is 9 and the sub-TLV length is 16. The format is as shown in
Figure 34.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CIR (Committed Information Rate) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PIR (Peak Information Rate) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CBS (Committed Burst Size) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PBS (Peak Burst Size) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 34: Ingress-CAR sub-TLV
Where:
CIR (4 bytes): Guaranteed rate in bits/second.
PIR (4 bytes): Burst rate in bits/second.
CBS (4 bytes): The token bucket in bytes.
PBS (4 bytes): Burst token bucket in bytes.
These fields are unsigned integers. More details about CIR, PIR, CBS,
and PBS can be found in [RFC2698].
7.3.3. Egress-CAR sub-TLV
The Egress-CAR sub-TLV indicates the authorized downstream Committed
Access Rate (CAR) parameters. The sub-TLV type of the Egress-CAR sub-
TLV is 10 and its sub-TLV length is 16 octets. The format of the
value part is as defined below.
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CIR (Committed Information Rate) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PIR (Peak Information Rate) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CBS (Committed Burst Size) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PBS (Peak Burst Size) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 35: Egress-CAR sub-TLV
Where:
CIR (4 bytes): Guaranteed rate in bits/second.
PIR (4 bytes): Burst rate in bits/second.
CBS (4 bytes): The token bucket in bytes.
PBS (4 bytes): Burst token bucket in bytes.
These fields are unsigned integers. More details about CIR, PIR, CBS,
and PBS can be found in [RFC2698].
7.3.4. If-Desc sub-TLV
The If-Desc sub-TLV is defined to designate an interface. It is an
optional sub-TLV that may be carried in those TLVs that have an "if-
index" or "out-if-index" field. The If-Desc sub-TLV is used as a
local unique identifier within a BNG.
The sub-TLV type is 11 and the sub-TLV length is 12 octets. The
format depends on the If-Type. The format of the value part is as
follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Type (1-5)| Chassis | Slot |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Slot | Port Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Port Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
If-Desc sub-TLV (Physical Port)
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Type (6-7) | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Logic-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Port Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
If-Desc sub-TLV (Virtual Port)
Figure 36: If-Desc sub-TLV Formats
Where:
If-Type: 8 bits in length, indicates the type of an interface.
Following types are defined in this document:
0: Reserved
1: Fast Ethernet (FE)
2: GE
3: 10GE
4: 100GE
5: Eth-Trunk
6: Tunnel
7: VE
8-255: Reserved.
Chassis (8 bits): Identifies the chassis that the interface
belongs to.
Slot (16 bits): Identifies the slot that the interface belongs to.
Sub-slot (16 bits): Identifies the sub-slot the interface belongs
to.
Port Number (16 bits): An identifier of a physical port/interface
(e.g., If-Type: 1-5). It is locally significant within the
slot/sub-slot.
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Sub-port Number (32 bits): An identifier of the sub-port. Locally
significant within its "parent" port (physical or virtual).
Logic-ID (32 bits): An identifier of a virtual interface (e.g.,
If-Type: 6-7)
7.3.5. IPv6 Address List sub-TLV
The IPv6 Address List sub-TLV is used to convey one or more IPv6
addresses. It is carried in the IPv6 Subscriber TLV. The sub-TLV
type is 12, the sub-TLV length is variable.
The format of IPv6 Addresses sub-TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ IPv6 Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ IPv6 Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ... ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ IPv6 Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 37: IPv6 Address List sub-TLV
Where:
IP Address (IPv6-Address): Each IP Address is an IP-Address type,
carries an IPv6 address.
7.3.6. Vendor sub-TLV
The Vendor sub-TLV is intended to be used inside the value portion of
the Vendor TLV (Section 7.13). It provides a Sub-Type that
effectively extends the sub-TLV type in the sub-TLV header and
provides for versioning of vendor sub-TLVs.
The value part of the Vendor sub-TLV is formatted as follows:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type | Sub-Type-Version |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ value (other as specified by vendor) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 38: Vendor sub-TLV
Where:
The sub-TLV type: 13.
The sub-TLV length: variable.
Vendor-ID (4 bytes): Vendor ID as defined in RADIUS [RFC2865].
Sub-Type (2 bytes): Used by the Vendor to distinguish multiple
different sub-TLVs.
Sub-Type-Version (2 bytes): Used by the Vendor to distinguish
different versions of a Vendor Defined sub-TLV sub-Type.
value: as specified by the vendor.
Since Vendor code will be handling the sub-TLV after the Vendor ID
field is recognized, the remainder of the sub-TLV can be organized
however the vendor wants. But it desirable for a vendor to be able to
define multiple different vendor sub-TLVs and to keep track of
different versions of its vendor defined sub-TLVs. Thus, it is
RECOMMENDED that the vendor assign a Sub-Type value for each of that
vendor's sub-TLVs that is different from other Sub-Type values that
vendor has used. Also, when modifying a vendor defined sub-TLV in a
way potentially incompatible with a previous definition, the vendor
SHOULD increase the value it is using in the Sub-Type-Version field.
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7.4. The Hello TLV
The Hello TLV is defined to be carried in the Hello message for
version and capabilities negotiation. It indicates the S-CUSP sub-
version and capabilities supported. The format of Hello TLV is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| VerSupported |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Capabilities |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 39: Hello TLV
Where:
The TLV type is 100.
The TLV length is 12 octets.
The value field consists of three parts:
VerSupported: 32 bits in length. This is a bit map of the Sub-
Versions of the S-CUSP protocol that the sender supports. This
document specifies Sub-Version zero of Major Version 1, that
is, Version 1.0. The VerSupported field MUST be non-zero. The
VerSupported bits are numbered from 0 as the most significant
bit. Bit 0 indicates support of Sub-Version zero, bit 1
indicates support of Sub-Version one, etc.
Vendor-ID: 4 bytes in length. Vendor ID, as defined in RADIUS
[RFC2865].
Capabilities: 32 bits in length. Flags that indicate the
support of particular capabilities by the sender of the Hello.
No Capabilities are defined in this document and so
implementations will set this field to zero. The Capabilities
field of the Hello TLV MUST be checked before any other TLVs in
the Hello because capabilities defined in the future might
extend existing TLVs or permit new TLVs.
After the exchange of Hello messages, the CP and UP each perform a
logical AND of the Sub-Version supported by the CP and the UP and
separately perform a logical AND of the Capabilities bits fields for
the CP and the UP.
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If the result of the AND of the Sub-Versions supported is zero, then
no session can be established and the connection is torn down. If the
result of the AND of the Sub-Versions supported is non-zero, then the
session uses the highest Sub-Version supported by both the CP and UP.
For example, if one side supports Sub-Versions 1, 3, 4, and 5
(VerSupported = 0x5C000000) and the other side supports 2, 3, and 4
(VerSupported = 0x38000000) then 3 and 4 are the Sub-Versions in
common and 4 is the highest Sub-Version supported by both sides. So
Sub-Version 4 is used for the session that has been negotiated.
The result of the logical AND of the Capabilities bits will show what
additional capabilities both sides support. If this result is zero,
there are no such capabilities so none can be used during the
session. If this result is non-zero, it shows the additional
capabilities that can be used during the session. The CP and the UP
MUST NOT use a capability unless both advertise support.
7.5. The Keep Alive TLV
The Keep Alive TLV is defined to be carried in the Hello message. It
provides timing information for the keep alive feature. The format
of Hello TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Keepalive | DeadTimer | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 40: Keep Alive TLV
Where:
The TLV type: 102.
The value of length: 4 octets.
Keepalive (8 bits): Indicates the maximum period of time (in
seconds) between two consecutive S-CUSP messages sent by the
sender of the message containing this TLV as an unsigned integer.
The minimum value for the Keepalive is 1 second. When set to 0,
once the session is established, no further Keepalive messages are
sent to the remote peer. A RECOMMENDED value for the Keepalive
frequency is 30 seconds.
DeadTimer (8 bits in length): Specifies the amount of time as an
unsigned integer number of seconds after the expiration of which
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the S-CUSP peer can declare the session with the sender of the
Hello message to be down if no S-CUSP message has been received.
The DeadTimer SHOULD be set to 0 and MUST be ignored if the
Keepalive is set to 0. A RECOMMENDED value for the DeadTimer is 4
times the value of the Keepalive.
The Reserved bits MUST be sent as zero and ignored on receipt.
7.6. The Error Information TLV
The Error Information TLV is a common TLV that can be used in many
Response (e.g., Update_Response message) and ACK messages (e.g.,
Addr_Allocation_Ack message, etc.). It is used to convey the
information about an error in the received S-CUSP message. The
format of the Error Information TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message-Type | Reserved | TLV-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 41: Error Information TLV
Where:
The TLV type: 101.
The value of length: 8 octets.
Message-Type(1 byte): This parameter is the message type of the
message containing an error.
Reserved (1 byte): MUST be sent as zero and ignored on receipt.
TLV-Type (2 bytes): Indicates which TLV caused the error.
Error Code: 4 bytes in length. Indicate the specific Error Code
(see Section 9.5).
7.7. BAS Function TLV
The BAS Function TLV is used by a CP to control the access mode,
authentication methods, and other related functions of an interface
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on a UP.
The format of the BAS Function TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access-Mode | Auth-Method4 | Auth-Method6 | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-TLVs (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 42: BAS Function TLV
Where:
The TLV type: 1.
The value of length: variable.
If-Index: 4 bytes in length, a unique identifier of an interface
of a BNG.
Access-Mode: 1 byte in length, indicates the access mode of the
interface. This document defines following values:
0: Layer 2 subscriber;
1: Layer 3 subscriber;
2: Layer 2 leased line;
3: Layer 3 leased line;
4-255: Reserved.
Auth-Method4: 1 byte in length, for IPv4 scenario, it indicates
the authentication on this interface; this field is defined as a
bitmap, this document defines following values (other bits are
reserved and MUST be sent as zero and ignored on receipt):
0x1: PPPoE authentication;
0x2: DOT1X authentication;
0x4: Web authentication;
0x8: Web fast authentication;
0x10: Binding authentication.
Auth-Method6: 1 byte in length, for IPv6 scenario, it indicates
the authentication on this interface; this field is defined as a
bitmap, this document defines following values (other bits are
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reserved and MUST be sent as zero and ignored on receipt):
0x1: PPPoE authentication;
0x2: DOT1X authentication;
0x4: Web authentication;
0x8: Web fast authentication;
0x10: Binding authentication;
sub-TLVs:
The IF-Desc sub-TLV can be carried.
If-Desc sub-TLV: carries the interface information.
The flags field is defined as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ |Y|X|P|I|N|A|S|F|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 43: Interface Flags
Where:
F (IPv4 Trigger) bit: Indicates whether IPv4 packets can
trigger a subscriber to go online. 1: enabled, 0: disabled.
S (IPv6 Trigger) bit: Indicates whether IPv6 packets can
trigger a subscriber to go online. 1: enabled, 0: disabled.
A (ARP Trigger) bit: Indicates whether ARP packets can trigger
a subscriber to go online. 1: enabled, 0: disabled.
N (ND Trigger) bit: Indicates whether ND packets can trigger a
subscriber to go online. 1: enabled, 0: disabled.
I (IPoE-Flow-Check): Used for UP detection. IPoE 1: Enable
traffic detection. 0: Disable traffic detection.
P (PPP-Flow-Check) bit: Used for UP detection. PPP 1: Enable
traffic detection. 0: Disable traffic detection.
X (ARP-Proxy) bit: 1: The interface is enabled with ARP proxy
and can process ARP requests across different Port+VLANs. 0:
The ARP proxy is not enabled on the interface, and only the ARP
requests of the same Port+VLAN are processed.
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Y (ND-Proxy) bit: 1: The interface is enabled with ND proxy and
can process ND requests across different Port+VLANs. 0: The ND
proxy is not enabled on the interface, and only the ND requests
of the same Port+VLAN are processed.
MBZ: Reserved bits that MUST be sent as zero and ignored on
receipt.
7.8. Routing TLVs
Normally, after an S-CUSP session is established between a UP and a
CP, the CP will allocate one or more blocks of IP addresses to the
UP. Those IP addresses will be allocated to subscribers who will
dial-up to the UP. In order to make sure that other nodes within the
network learn how to reach those IP addresses, the CP needs to
install one or more routes that can reach those IP addresses on the
UP and notify the UP to advertise the routes to the network.
The Routing TLVs are used by a CP to notify a UP of the network
routing. They can be carried in the Update_Request message and
Sync_Data message.
7.8.1. IPv4 Routing TLV
The IPv4 Routing TLV is used to carry IPv4 network routing related
information.
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The format of the TLV value part is as below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Dest-Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next-Hop |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Out-If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cost |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Type | Reserved |A|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 44: IPv4 Routing TLV
Where:
The TLV Type: 7
The TLV Length: Variable
User-ID: 4 bytes in length. Carries the user identifier. This
field is filled with all Fs when a non-user route is delivered to
the UP.
Dest-Address (IPv4-Address type): Identifies the destination
address.
Next-Hop: (IPv4-Address type): Identifies the next hop address.
Out-If-Index (4 bytes): Indicates the interface index.
Cost (4 bytes): The cost value of the route.
Tag (4 bytes): The tag value of the route.
Route-Type (2 bytes): Indicates the route type. The options are
as follows:
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0: User host route
1: Radius authorization FrameRoute
2: Network segment route
3: Gateway route
4: Radius authorized IP route
5: L2TP LNS side user route
Advertise-Flag: 1 bit. Indicates whether the route should be
advertised by the UP. Following flags are defined:
0: Not advertised,
1: advertised.
sub-TLVs: The VRF-Name and/or If-Desc sub-TLVs can be carried.
VRF-Name sub-TLV: indicates which VRF the route belongs to.
If-Desc sub-TLV: carries the interface information.
The Reserved field MUST be sent as zero and ignored on receipt.
7.8.2. IPv6 Routing TLV
The IPv6 Routing TLV is used to carry IPv6 network routing
information.
The format of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ IPv6 Dest-Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ IPv6 Next-Hop ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Out-If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Cost |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Type | Reserved |A|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 45: IPv6 Routing TLV
Where:
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The TLV Type: 7
The TLV Length: Variable
User-ID: 4 bytes in length. Carries the user identifier. This
field is filled with all Fs when a non-user route is delivered to
the UP.
IPv6 Dest-Address (IPv6-Address type): Identifies the destination
address.
IPv6 Next-Hop: (IPv6-Address type): Identifies the next hop
address.
Out-If-Index (4 bytes): Indicates the interface index.
Cost (4 bytes): The cost value of the route.
Tag (4 bytes): The tag value of the route.
Route-Type: (2 bytes): Indicates the route type. The options are
as follows:
0: User host route
1: Radius authorization FrameRoute
2: Network segment route
3: Gateway route
4: Radius authorized IP route
5: L2TP LNS side user route
Advertise-Flag: 1 bit. Indicates whether the route should be
advertised by the UP. Following flags are defined:
0: Not advertised,
1: advertised.
sub-TLVs: If-Desc and VRF-Name sub-TLVs can be carried.
VRF-Name sub-TLV: Indicates the VRF to which the subscriber
belongs.
If-Desc sub TLV: carries the interface information.
The Reserved field MUST be sent as zero and ignored on receipt.
7.9. Subscriber TLVs
The Subscriber TLVs are defined for a CP to send the basic
information about a user to a UP.
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7.9.1. Basic Subscriber TLV
The Basic Subscriber TLV is used to carry the basic common
information for all kinds of access subscribers. It is carried in an
Update_Request message.
The format of the Basic Subscriber TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User MAC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User MAC | Oper ID | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Access Type |Sub-access Type| Account Type | Address Family|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| C-VID | P-VID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Detect Times | Detect Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 46: Basic Subscriber TLV
Where:
The TLV Type: 2.
The TLV Length: variable in length.
User-ID (4 bytes): The identifier of a subscriber.
Session-ID (4 bytes): Session ID of a PPPoE subscriber. Zero
means non-PPPoE subscriber.
User-Mac (MAC-Addr type): The MAC Address of a subscriber.
Oper-ID (1 byte): Indicates the ID of an operation performed by a
user. This field is carried in the response from the UP.
Reserved (1 byte): MUST be sent as zero and ignored on receipt.
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Access-Type (1 byte):
1: PPP access (PPP [RFC1661])
2: PPP over Ethernet over ATM access (PPPoEoA)
3: PPP over ATM access (PPPoA [RFC3336])
4: PPP over Ethernet access (PPPoE [RFC2516])
5: PPPoE over VLAN access (PPPoEoVLAN [RFC2516])
6: PPP over LNS access (PPPoLNS)
7: IP over Ethernet DHCP access (IPoE_DHCP)
8: IP over Ethernet EAP authentication access (IPoE_EAP)
9: IP over Ethernet Layer 3 access (IPoE_L3)
10: IP over Ethernet Layer 2 Static access (IPoE_L2_STATIC)
11: Layer 2 Leased Line access (L2_Leased_Line)
12: Layer 2 VPN Leased Line access (L2VPN_Leased_Line)
13: Layer 3 Leased Line access (L3_Leased_Line)
14: Layer 2 Leased line Sub-User access
(L2_Leased_Line_SUB_USER)
15: L2TP LAC tunnel access (L2TP_LAC)
16: L2TP LNS tunnel access (L2TP_LNS)
Sub-Access-Type (1 byte): Indicates whether PPP termination or PPP
relay is used.
0: Reserved
1: PPP Relay (for LAC)
2: PPP termination (for LNS)
Account-Type(1 byte):
0: Collects statistics on IPv4 and IPv6 traffic of terminals
independently.
1: Collects statistics on IPv4 and IPv6 traffic of terminals.
Address Family (1 byte)
1: IPv4
2: IPv6
3: dual stack
C-VID (VLAN-ID): Indicates the inner VLAN ID. The value 0
indicates that the VLAN ID is invalid. The default value of PRI
is 7, the value of DEI is 0, and the value of VID is 1~4094. The
PRI value can also be obtained by parsing terminal packets.
P-VID (VLAN-ID): Indicates the outer VLAN ID. The value 0
indicates that the VLAN ID is invalid. The format is the same as
that for C-VID.
Detect-Times (2 bytes): Number of detection timeout times. The
value 0 indicates that no detection is performed.
Detect-Interval (2 bytes): Detection interval in seconds.
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If-Index (4 bytes): Interface index.
Sub-TLVs: VRF-Name sub-TLV and If-Desc sub-TLV can be carried.
VRF-Name sub-TLV: Indicates the VRF to which the subscriber
belongs.
If-Desc sub-TLV: carries the interface information.
The Reserved field MUST be sent as zero and ignored on receipt.
7.9.2. PPP Subscriber TLV
The PPP Subscriber TLV is defined to carry PPP information of a User
from a CP to a UP. It will be carried in an Update_Request message
when PPPoE or L2TP access is used.
The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MSS | Reserved |M|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MRU | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Magic Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer Magic Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 47: PPP Subscriber TLV
Where:
The TLV type: 3.
The TLV length: 12 octets.
User-ID (4 bytes): The identifier of a subscriber.
MSS-Value (2 bytes): Indicates the MSS value (in bytes).
MSS-Enable (M) (1 bit): Indicates whether the MSS is enabled.
0: Disabled.
1: Enabled.
MRU (2 bytes): PPPoE local MRU (in bytes).
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Magic-Number (4 bytes): Local magic number in PPP negotiation
packets.
Peer-Magic-Number (4 bytes): Remote peer magic number.
The Reserved fields MUST be sent as zero and ignored on receipt.
7.9.3. IPv4 Subscriber TLV
The IPv4 Subscriber TLV is defined to carry IPv4 related information
for a BNG user. It will be carried in an Update_Request message when
IPv4 IPoE, or PPPoE access is used.
The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Gateway IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MTU | Reserved |U|E|W|P|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ VRF-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 48: IPv4 Subscriber TLV
Where:
The TLV type: 4.
The TLV length: variable.
User-ID (4 bytes): The identifier of a subscriber.
User-IPv4 (IPv4-Address): The IPv4 address of the subscriber.
Gateway-IPv4 (IPv4-Address): The gateway address of the
subscriber.
Portal Force (P) (1 bit ): Push advertisement, 0: off, 1: on.
Web-Force (W) (1 bit): Push IPv4 Web. 0: off, 1: on.
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Echo-Enable (E) (1 bit): UP returns ARP Req or PPP Echo. 0: off,
1: on.
IPv4-URPF (U) (1 bit): User Unicast Reverse Path Forwarding (URPF)
flag. 0: off, 1: on.
MTU 2 bytes MTU value. The default value is 1500.
VRF-Name Sub-TLV: Indicates the subscriber belongs to which VRF.
The Reserved field MUST be sent as zero and ignored on receipt.
7.9.4. IPv6 Subscriber TLV
The IPv6 Subscriber TLV is defined to carry IPv6 related information
for a BNG user. It will be carried in an Update_Request message when
IPv6 IPoE, or PPPoE access is used.
The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ User PD-Address (IPv6 Address List sub-TLV) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Gateway ND-Address (IPv6 Address List sub-TLV) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User IANA Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Interface ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Interface ID (cont.) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MTU | Reserved |U|E|W|P|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ VRF Name sub-TLV (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 49: IPv6 Subscriber TLV
Where:
The TLV type: 5.
The TLV length: variable.
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User-ID (4 bytes): The identifier of a subscriber.
User PD-Addresses (IPv6 Address List): Carries a list of Prefix
Delegation (PD) addresses of the subscriber.
User ND-Addresses (IPv6 Address List): Carries a list of Neighbor
Discovery (ND) addresses of the subscriber.
User IANA-Address (IPv6-Address): The IANA address of the
subscriber.
IPv6 Interface ID (8 bytes): The identifier of an IPv6 interface.
Portal Force 1 bit (P): Push advertisement, 0: off, 1: on.
Web-Force 1 bit (W): Push IPv6 Web, 0: off, 1: on.
Echo-Enable 1 bit (E): The UP returns ARP Req or PPP Echo. 0: off;
1: on.
IPv6-URPF 1 bit (U): User Reverse Path Forwarding (URPF) flag, 0:
off; 1: on.
MTU (2 bytes): The MTU value. The default value is 1500.
VRF-Name Sub-TLV: Indicates the VRF to which the subscriber
belongs.
The Reserved field MUST be sent as zero and ignored on receipt.
7.9.5. IPv4 Static Subscriber Detect TLV
The IPv4 Static Subscriber Detect TLV is defined to carry IPv4
related information for a static access subscriber. It will be
carried in an Update_Request message when IPv4 static access on a UP
needs to be enabled.
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The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| C-VID | P-VID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Gateway Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User MAC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User MAC (cont.) | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 50: IPv4 Static Subscriber TLV
Where:
The TLV type: 6.
The TLV length: variable.
If-Index (4 bytes): The interface index of the interface from
which the subscriber will dial-up.
C-VID (VLAN-ID): Indicates the inner VLAN ID. The value 0
indicates that the VLAN ID is invalid. A valid value is 1~4094.
P-VID (VLAN-ID): Indicates the outer VLAN ID. The value 0
indicates that the VLAN ID is invalid. The format is the same as
that of the C-VID. A valid value is 1~4094. For a single-layer
VLAN, set this parameter to PeVid.
User Address (IPv4-Addr): The user's IPv4 address.
Gateway Address (IPv4-Addr): The gateway's IPv4 Address.
User-MAC (MAC-Addr type): The MAC address of the subscriber.
Sub-TLVs: VRF-Name and If-Desc sub-TLVs may be carried.
VRF-Name sub-TLV: Indicates the VEF to which the subscriber
belongs.
If-Desc sub-TLV: Carries the interface information.
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The Reserved field MUST be sent as zero and ignored on receipt.
7.9.6. IPv6 Static Subscriber Detect TLV
The IPv6 Static Subscriber Detect TLV is defined to carry IPv6
related information for a static access subscriber. It will be
carried in an Update_Request message when needed to enable IPv6
static subscriber detection on a UP.
The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| C-VID | P-VID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ User Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Gateway Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User MAC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User MAC (cont.) | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 51: IPv6 Static Subscriber Detect TLV
Where:
The TLV type: 6.
The TLV length: variable.
If-Index (4 bytes): The interface index of the interface from
which the subscriber will dial-up.
C-VID (VLAN-ID): Indicates the inner VLAN ID. The value 0
indicates that the VLAN ID is invalid. A valid value is 1~4094.
P-VID (VLAN-ID): Indicates the outer VLAN ID. The value 0
indicates that the VLAN ID is invalid. The format is the same as
that the of C-VID. A valid value is 1~4094. For a single-layer
VLAN, set this parameter to PeVid.
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User Address (IPv6-Address type): The subscriber's IPv6 address.
Gateway Address (IPv6-Address type): The gateway's IPv6 Address.
User-MAC (MAC-Addr type): The MAC address of the subscriber.
sub-TLVs: VRF-Name and If-Desc sub-TLVs may be carried
VRF-Name Sub-TLV: Indicates the VRF to which the subscriber
belongs.
If-Desc sub-TLV: Carries the interface information.
The Reserved field MUST be sent as zero and ignored on receipt.
7.9.7. L2TP-LAC Subscriber TLV
The L2TP-LAC Subscriber TLV is defined to carry the related
information for a L2TP LAC access subscriber. It will be carried in
an Update_Request message when L2TP LAC access is used.
The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Tunnel ID | Local Session ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote Tunnel ID | Remote Session ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 52: L2TP-LAC Subscriber TLV
Where:
The TLV type: 11.
The TLV length: 12 octets.
User-ID (4 bytes): The identifier of a user/subscriber.
Local-Tunnel-ID (2 bytes): The local ID of the L2TP tunnel.
Local-Session-ID (2 bytes): The local session ID with the L2TP
tunnel.
Remote-Tunnel-ID (2 bytes): The remote ID of the L2TP tunnel.
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Remote-Session-ID (2 bytes): The remote session ID of the L2TP
tunnel.
7.9.8. L2TP-LNS Subscriber TLV
The L2TP-LNS Subscriber TLV is defined to carry the related
information for a L2TP LNS access subscriber. It will be carried in
an Update_Request message when L2TP LNS access is used.
The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Tunnel ID | Local Session ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote Tunnel ID | Remote Session ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 53: L2TP-LNS Subscriber TLV
Where:
The TLV type: 12.
The TLV length: 12 octets.
User-ID (4 bytes): The identifier of a user/subscriber.
Local-Tunnel-ID (2 bytes): The local ID of the L2TP tunnel.
Local-Session-ID (2 bytes): The local session ID with the L2TP
tunnel.
Remote-Tunnel-ID (2 bytes): The remote ID of the L2TP tunnel.
Remote-Session-ID (2 bytes): The remote session ID of the L2TP
tunnel.
7.9.9. L2TP-LAC Tunnel TLV
The L2TP-LAC Tunnel TLV is defined to carry the L2TP LAC tunnel
related information. It will be carried in the Update_Request
message when L2TP LAC access is used.
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The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Tunnel ID | Remote Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Tunnel Source Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Tunnel Destination Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ VRF Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 54: L2TP-LAC Tunnel TLV
Where:
The TLV type: 13.
The TLV length: variable.
Local-Tunnel-ID (2 bytes): The local ID of the L2TP tunnel.
Remote-Tunnel-ID (2 bytes): The remote ID of the L2TP tunnel.
Source-Port (2 bytes): The source UDP port number of an L2TP
subscriber.
Dest-Port (2 bytes): The destination UDP port number of an L2TP
subscriber.
Source-IP (IPv4/v6): The source IP address of the tunnel.
Dest-IP (IPv4/v6): The destination IP address of the tunnel.
VRF-Name Sub-TLV: The VRF name to which the L2TP subscriber tunnel
belongs.
7.9.10. L2TP-LNS Tunnel TLV
The L2TP-LNS Tunnel TLV is defined to carry the L2TP LNS tunnel
related information. It will be carried in the Update_Request
message when L2TP LNS access is used.
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The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Tunnel ID | Remote Tunnel ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Tunnel Source Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Tunnel Destination Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ VRF Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 55: L2TP-LNS Tunnel TLV
Where:
The TLV type: 14.
The TLV length: variable.
Local-Tunnel-ID (2 bytes): The local ID of the L2TP tunnel.
Remote-Tunnel-ID (2 bytes): The remote ID of the L2TP tunnel.
Source-Port (2 bytes): The source UDP port number of an L2TP
subscriber.
Dest-Port (2 bytes): The destination UDP port number of an L2TP
subscriber.
Source-IP (IPv4/v6): The source IP address of the tunnel.
Dest-IP (IPv4/v6): The destination IP address of the tunnel.
VRF-Name Sub-TLV: The VRF name to which the L2TP subscriber tunnel
belongs.
7.9.11. Update Response TLV
The Update Response TLV is used to return the operation result of an
update request. It is carried in the Update_Response message as a
response to the Update_Request message.
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The format of Update Response TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User-Trans-ID | Oper-Code | Oper-Result | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error-Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 56: Update Response TLV
Where:
The TLV type: 302.
The TLV length: 12.
User-ID (4 bytes): A unique identifier of an user/subscriber.
User-Trans-ID (1 byte): In the case of dual-stack access or when
modifying a session, User-Trans-ID is used to identify a user
operation transaction. It is used by the CP to correlate a
response to a specific request.
Oper-Code (1 byte): Operation code. 1: update, 2: delete.
Oper-Result (1 byte): Operation Result. 0: Success, Others:
Failure.
Error-Code (4 bytes): Operation failure cause code. for details,
see Section 9.5.
The Reserved field MUST be sent as zero and ignored on receipt.
7.9.12. Subscriber Policy TLV
The Subscriber Policy TLV is used to carry the policies that will be
applied to a subscriber. It is carried in the Update_Request
message.
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The format of the TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| I-Priority | E-Priority | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 57: User QoS Policy Information TLV
Where:
The TLV type: 6.
The TLV length: variable.
User-ID (4 bytes): The identifier of a user/subscriber.
Ingress-Priority (1 byte): Indicates the upstream priority. The
value range is 0~7.
Egress-Priority (1 byte): Indicates the downstream priority. The
value range is 0~7.
sub-TLVs: The sub-TLVs that are present can occur in any order.
Ingress-CAR sub-TLV: Upstream CAR.
Egress-CAR sub-TLV: Downstream CAR.
Ingress-QoS-Profile sub-TLV: Indicates the name of the QoS-
Profile profile in the upstream direction.
Egress-QoS-Profile Sub-TLV: Indicates the name of the QoS-
Profile profile in the downstream direction.
User-ACL-Policy Sub-TLV: All ACL user policies, including
v4ACLIN, v4ACLOUT, v6ACLIN, v6ACLOUT, v4WEBACL, v6WEBACL,
v4SpecialACL, and v6SpecialACL.
Multicast-Profile4 Sub-TLV: IPv4 multicast policy name.
Multicast-Profile6 Sub-TLV: IPv6 multicast policy name.
NAT-Instance Sub-TLV: Indicates the instance ID of a NAT user.
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The Reserved field MUST be sent as zero and ignored on receipt.
7.9.13. Subscriber CGN Port Range TLV
The Subscriber CGN Port Range TLV is used to carry the NAT public
address and port range. It will be carried in the Update_Response
message when CGN is used.
The format of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NAT-Port-Start | NAT-Port-End |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| NAT-Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 58: Subscriber CGN Port Range TLV
Where:
The TLV type: 15.
The TLV length: 12 octets.
User-ID (4 bytes): The identifier of a user/subscriber.
NAT-Port-Start (2 bytes): The start port number.
NAT-Port-End (2 bytes): The end port number.
NAT-Address (4 bytes): The NAT public network address.
7.10. Device Status TLVs
The TLVs in this section are for reporting Interface and Board level
information from the UP to the CP.
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7.10.1. Interface Status TLV
The Interface Status TLV is used to carry the status information of
an interface on a UP. It is carried in a Report message.
The format of the value part of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| If-Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MAC Address (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MAC Address (lower part) | Phy-State | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-TLVs (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 59: Interface Status TLV
Where:
The TLV type: 200.
The TLV length: variable.
If-Index (4 bytes): Indicates the interface index.
MAC-Address (MAC-Addr type): Interface MAC address.
Phy-State (1 byte): Physical status of the interface. 0: down, 1:
Up
MTU (4 bytes): Interface MTU value.
sub-TLVs: The If-Desc and VRF-Name sub-TLVs can be carried.
The Reserved field MUST be sent as zero and ignored on receipt.
7.10.2. Board Status TLV
The Board Status TLV is used to carry the status information of a
board on an UP. It is carried in a Report message.
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The format of Board Status TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Board-Type | Board-State | Reserved | Chassis |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Slot | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 60: Interface Resource TLV
Where:
The TLV type: 201.
The TLV length: 8 octets.
Chassis (1 byte): The chassis number of the Board.
Slot (1 byte): The slot number of the Board.
Sub-Slot (1 byte): The sub-slot number of the Board.
Board-Type (1 byte):
1: CGN Service Process Unit (SPU) board.
2: Line Process Unit (LPU) Board.
Board-State (1 byte):
0: Normal.
1: Abnormal.
The reserved field MUST be sent as zero and ignored on receipt.
7.11. CGN TLVs
7.11.1. Address Allocation Request TLV
The Address Allocation Request TLV is used to request address
allocation from CP. An address Pool-Name sub-TLV is carried to
indicate from which address pool to allocate addresses. The Address
Allocation Request TLV is carried in the Addr_Allocation_Req message.
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The format of the value part of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Pool-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 61: Address Allocation Request TLV
Where:
The TLV type: 400.
The TLV length: variable.
Pool-Name sub-TLV: Indicates from which Address pool to allocate
address.
7.11.2. Address Allocation Response TLV
The Address Allocation Response TLV is used to return the address
allocation result, it is carried the Addr_Allocation_Ack message.
The value part of the Address Allocation Response TLV is formatted as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Lease Time |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Addr and Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Addr and Mask continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error-Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Pool-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 62: Address Assignment Response TLV
Where:
The TLV type: 401.
The TLV length: variable.
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Lease Time (4 bytes): Duration of address lease in seconds.
IPv4 Addr and Mask (IPv4-Address type): The allocated IPv4
address.
Error-Code (4 bytes): Indicates success or an error.
0: Success.
1: Failure.
3001 (Pool-Mismatch): The corresponding address pool cannot be
found.
3002 (Pool-Full): The address pool is fully allocated and no
address segment is available.
Pool-Name sub-TLV: A Pool-Name sub-TLV to indicate from which
Address pool the address is allocated.
7.11.3. Address Renewal Request TLV
The Address Renewal Request TLV is used to request address renewal
from the CP. It is carried the Addr_Renew_Req message.
The format of this TLV value is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Pool-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 63: Address Renewal Request TLV
Where:
The TLV type: 402.
The TLV length: variable.
IPv4 Addr and Mask (IPv4-Addr): The IPv4 address to be renewed.
Pool Name sub-TLV: A Pool-Name sub-TLV to indicate from which
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Address pool to renew the address.
7.11.4. The Address Renewal Response TLV
The Address Renewal Response TLV is used to return the address
renewal result. It is carried in the Addr_Renew_Ack message.
The format of this TLV value is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error-Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Pool-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 64: Address Renewal Response TLV
Where:
The TLV type: 403.
The TLV length: variable.
Client-IP (IPv4-Address type): The renewed IPv4 address.
Error Code (4 bytes): Indicates success or an error:
0: Renew success.
1: Renew failed.
3001 (Pool-Mismatch): The corresponding address pool cannot be
found.
3002 (Pool-Full): The address pool is fully allocated and no
address segment is available.
3003 (Subnet-Mismatch): The address pool subnet cannot be
found.
3004 (Subnet-Conflict): Subnets in the address pool have been
assigned to other clients.
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Pool Name sub-TLV: A Pool-Name Sub-TLV to indicate from which
Address pool to renew the address.
7.11.5. Address Release Request TLV
The Address Release Request TLV is used to release an IPv4 address.
It is carried in the Addr_Release_Req message.
The value part of this TLV is formatted as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Pool-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 65: Address Release Request TLV
Where:
The TLV type: 404.
The TLV length: variable.
IPv4 Address and Mask (IPv4-Address type): The IPv4 address be
released.
Pool-Name sub-TLV: A Pool-Name Sub-TLV to indicate from which
Address pool to release the address.
7.11.6. The Address Release Response TLV
The Address Release Response TLV is used to return the address
release result. It is carried in the Addr_Release_Ack message.
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The format of this TLV is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Address and Mask continued |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error-Code |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Pool-Name sub-TLV ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 66: Address Renewal Response TLV
Where:
The TLV type: 405.
The TLV length: variable.
Client-IP (IPv4-Address type): The released IPv4 address.
Error-Code (4 bytes): Indicates success or an error.
0: Address release success.
1: Address release failed.
3001 (Pool-Mismatch): The corresponding address pool cannot be
found.
3003 (Subnet-Mismatch): The address cannot be found.
3004 (Subnet-Conflict): The address has been allocated to
another subscriber.
Pool-Name sub-TLV: A Pool-Name Sub-TLV to indicate from which
address pool to release the address.
7.12. Event TLVs
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7.12.1. Subscriber Traffic Statistics TLV
The Subscriber Traffic Statistics TLV is used to return the traffic
statistics of a user/subscriber. The format of this TLV is as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Statistics Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Packets (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Packets (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Bytes (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Bytes (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Loss Packets (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Loss Packets (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Loss Bytes (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Ingress Loss Bytes (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Packets (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Packets (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Bytes (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Bytes (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Loss Packets (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Loss Packets (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Loss Bytes (upper part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Egress Loss Bytes (lower part) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 67: Subscriber Traffic Statistics TLV
Where:
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The TLV type: 300.
The TLV length: 72 octets.
User-ID (4 bytes): The user/subscriber identifier.
Statistics-Type (4 bytes): Traffic type. It can be one of the
following options:
0: IPv4 traffic.
1: IPv6 traffic.
2: Dual stack traffic.
Ingress Packets (8 bytes): The number of the packets in upstream
direction.
Ingress Bytes (8 bytes): The bytes of the upstream traffic.
Ingress Loss Packets (8 bytes): The number of the lost packets in
upstream direction.
Ingress Loss Bytes (8 bytes): The bytes of the lost upstream
packets.
Egress Packets (8 bytes): The number of the packets in downstream
direction.
Egress Bytes (8 bytes): The bytes of the downstream traffic.
Egress Loss Packets (8 bytes): The number of the lost packets in
downstream direction.
Egress Loss Bytes (8 bytes): The bytes of the lost downstream
packets.
7.12.2. Subscriber Detection Result TLV
The Subscriber Detection Result TLV is used to return the detection
result of a subscriber. Subscriber detection is a function to detect
whether a subscriber is online or not. The result can be used by the
CP to determine how to deal with the subscriber session. (e.g.,
delete the session if detection failed).
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The format of this TLV value part is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| User-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Detect Type | Detect Result | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 68: Subscriber Detection Result TLV
Where:
The TLV type: 301.
The TLV length: 8 octets.
User-ID (4 bytes): A user/subscriber identifier.
Detect-Type (1 byte):
0: IPv4 detection.
1: IPv6 detection.
2: PPP detection.
Detect-Result (1 bytes):
0: Indicates that the detection is successful.
1: Detection failure. The UP needs report only when the
detection fails.
The Reserved field MUST be sent as zero and ignored on receipt.
7.13. Vendor TLV
The Vendor ID TLV occurs as the first TLV in the Vendor message
(Section 6.6). It provides a Sub-Type that effectively extends the
message type in the message header, provides for versioning of vendor
TLVs, and can accommodate sub-TLVs.
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The value part of the Vendor TLV is formatted as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Vendor ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sub-Type | Sub-Type-Version |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ sub-TLVs (optional) ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 69: Vendor TLV
Where:
The TLV type: 1024.
The TLV length: variable.
Vendor-ID (4 bytes): Vendor ID ass defined in RADIUS [RFC2865].
Sub-Type (2 bytes): Used by the Vendor to distinguish multiple
different vendor messages.
Sub-Type-Version (2 bytes): Used by the Vendor to distinguish
different versions of a Vendor Defined message sub-type.
Sub-TLVs (variable): Sub-TLVs as specified by the vendor.
Since Vendor code will be handling the TLV after the Vendor ID field
is recognized, the remainder of the TLV value can be organized
however the vendor wants. But it is desirable for a vendor to be able
to define multiple different vendor messages and to keep track of
different versions of its vendor defined messages. Thus, it is
RECOMMENDED that the vendor assign a Sub-Type value for each vendor
message that it defines different from other Sub-Type values that
vendor has used. Also, when modifying a vendor defined message in a
way potentially incompatible with a previous definition, the vendor
SHOULD increase the value it is using in the Sub-Type-Version field.
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8. Implementation Status
RFC Editor: Please remove this section before publication.
This section discusses the status of implementations that have
provided information and the testing of this protocol at the time of
posting of this Internet-Draft, and is based on the proposal in
[RFC7942] ("Improving Awareness of Running Code: The Implementation
Status Section"). The description of implementations in this section
is intended to assist in processing drafts to RFCs.
Please note that the listing of any individual implementation or test
results here does not imply endorsement by the RFC Editor or the
IETF. Furthermore, no effort has been spent to verify the
information presented here that was supplied by contributors. This
is not intended as, and must not be construed to be, a catalog of
available implementations or their testing or features. Readers are
advised to note that other implementations may exist.
According to [RFC7942], "this will allow reviewers ... to assign due
consideration to documents that have the benefit of running code,
which may serve as evidence of valuable experimentation and feedback
that have made the implemented protocols more mature.".
8.1. Implementations
Information on three S-CUSP implementations appears below.
8.1.1. Huawei Technologies
Name: Cloud-based BNG.
Maturity: Production.
Coverage: According to S-CUSP protocol.
Contact information:
Zhouyi Yu: yuzhouyi@huawei.com
Date: 2018-11-01
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8.1.2. ZTE
Name: ZXR10 V6000 vBRAS
Maturity: Production
Coverage: According to S-CUSP protocol.
Contact information:
Yong Chen: 10056167@zte.com.cn
Huaibin Wang: 10008729@zte.com.cn
Date: 2018-12-01
8.1.3. H3C
Name: CUSP protocol for BRAS Control Plane and User Plan
Separation
Maturity: Research
Coverage: According to S-CUSP protocol
Contact information: mengdan@h3c.com; liuhanlei@h3c.com
Date: 2019-1-30
8.2. Hackathon
Successful use of the protocol at the IETF-102 Hackathon, Montreal,
Quebec, in 2018.
Hackathon Project: Control Plane and User Plane Separation BNG
control channel Protocol (CUSP)
Champions: Zhenqiang Li, Michael Wang
Report: See
github.com/IETF-Hackathon/ietf102-project-presentations/blob/
master/IETF102-hackathon-presentation-CUSP.pptx
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8.3. EANTC Testing
EANTC (European Advanced Networking Test Center (www.eantc.de))
tested the Huawei implementation. Their summary was as follows:
"EANTC tested advanced aspects of the Cloud-based Broadband Network
Gateway (vBNG) with a focus on performance, scalability and high
availability with up to 20 Million emulated subscribers. The solution
performed very well across all test scenarios."
See report at
www.eantc.de/fileadmin/eantc/downloads/News/2018/EANTC-vBRAS-
phase2.pdf
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9. Summary of Major S-CUSP Codepoints
This section provides tables of the major S-CUSP codepoints,
particularly message types, TLV types, TLV operation codes, sub-TLV
types, and error codes. In most cases, references are provided to
relevant sections elsewhere in this document.
9.1. Message Types
Type Name Section of this document
------- ---------------- ------------------------
0 - Reserved
1 Hello 6.2.1.
2 Keepalive 6.2.2.
3 Sync_Request 6.2.3.
4 Sync_Begin 6.2.4.
5 Sync_Data 6.2.5.
6 Sync_End 6.2.6.
7 Update_Request 6.2.7.
8 Update_Response 6.2.8.
9 Report 6.4.
10 Event 6.3.
11 Vendor 6.6.
12 Error 6.7.
13-199 - Unassigned
200 Addr_Allocation_Req 6.5.1.
201 Addr_Allocation_Ack 6.5.2.
202 Addr_Renew_Req 6.5.3.
203 Addr_Renew_Ack 6.5.4.
204 Addr_Release_Req 6.5.5.
205 Addr_Release_Ack 6.5.6.
206-254 - Unassigned
255 - Reserved
9.2. TLV Types
Type Name Usage Description
------ ------------ --------------------------
0 reserved -
1 BAS Function Carries the BNG access
functions to be enabled or
disabled on specified
interfaces.
2 Basic Subscriber Carries the basic information
about a BNG subscriber.
3 PPP Subscriber Carries the PPP information
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about a BNG subscriber.
4 IPv4 Subscriber Carries the IPv4 address of a
BNG subscriber.
5 IPv6 Subscriber Carries the IPv6 address of a
BNG subscriber.
6 Subscriber Policy Carries the policy information
applied to a BNG subscriber.
7 IPv4 Routing Carries the IPv4 network
routing information.
8 IPv6 Routing Carries the IPv6 network
routing information.
9 IPv4 Static Subscriber Detect Carries the IPv4 static
subscriber detect information.
10 IPv6 Static Subscriber Detect Carries the IPv6 static
subscriber detect information.
11 L2TP-LAC Subscriber Carries the L2TP LAC
subscriber information.
12 L2TP-LNS Subscriber Carries the L2TP LNS
subscriber information.
13 L2TP-LAC-Tunnel Carries the L2TP LAC tunnel
subscriber information.
14 L2TP-LNS-Tunnel Carries the L2TP LNS tunnel
subscriber information.
15 Subscriber CGN Port Range Carries the public IPv4
address and related port range
of a BNG subscriber.
16-99 unassigned -
100 Hello Used for version and Keep
Alive timers negotiation.
101 Error Information Carried in the Ack of the
control message. Carries the
processing result, success, or
error.
102 Keep Alive Carried in the Hello message
for Keep Alive timers
negotiation.
103-199 unassigned -
200 Interface Status Interfaces status reported by
the UP including physical
interfaces, sub-interfaces,
trunk interfaces, and tunnel
interfaces.
201 Board Status Board information reported by
the UP including the board
type and in-position status.
202-299 unassigned -
300 Subscriber Traffic Statistics User traffic statistics.
301 Subscriber Detection Results User detection information.
302 Update Response The processing result of a
subscriber session update.
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303-299 unassigned -
400 Address Allocation Request Request address allocation.
401 Address Allocation Response Address allocation response.
402 Address Renewal Request Request for address lease
renewal.
403 Address Renewal Response Response to a request for
extending an IP address lease.
404 Address Release Request Request to release the
address.
405 Address Release Response Ack of a message releasing an
IP address.
406-1023 unassigned -
1024 Vendor As implemented by vendor.
1039-4095 unassigned -
9.3. TLV Operation Codes
TLV operation codes appear in the Oper field in the header of some
TLVs. See Section 7.1.
Code Operation
---- ----------
0 - reserved
1 Update
2 Delete
3-15 - unassigned
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9.4. Sub-TLV Types
See Section 7.3.
Type Name Section of this document
---- ------------------ ------------------------
0 - reserved
1 VRF Name 7.3.1.
2 Ingress-QoS-Profile 7.3.1.
3 Egress-QoS-Profile 7.3.1.
4 User-ACL-Policy 7.3.1.
5 Multicast-ProfileV4 7.3.1.
6 Multicast-ProfileV6 7.3.1.
7 Ingress-CAR 7.3.2.
8 Egress-CAR 7.3.3.
9 NAT-Instance 7.3.1.
10 Pool-Name 7.3.1.
11 If-Desc 7.3.4.
12 IPv6-Address List 7.3.5.
13 Vendor 7.3.6.
12-64534 - unassigned
65535 - reserved
9.5. Error Codes
Value Name Remarks
------- ------- --------
0 Success Success
1 Fail Malformed message received.
2 TLV-Unknown One or more of the TLVs was not
understood.
3 TLV-Length The TLV length is abnormal.
4-999 - unassigned Unassigned basic error codes.
1000 - reserved
1001 Version-Mismatch The version negotiation fails. Terminate.
The subsequent service processes
corresponding to the UP are suspended.
1002 Keepalive Error The keepalive negotiation fails.
1003 Timer Expires The establishment timer expired.
1004-1999 - unassigned Unassigned error codes for version
negotiation.
2000 - reserved
2001 Synch-NoReady The data to be smoothed is not ready.
2002 Synch-Unsupport The request for smooth data is not
supported.
2003-2999 - unassigned Unassigned data synchronization error
codes.
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3000 - reserved
3001 Pool-Mismatch The corresponding address pool cannot be
found.
3002 Pool-Full The address pool is fully allocated and no
address segment is available.
3003 Subnet-Mismatch The address pool subnet cannot be found.
3004 Subnet-Conflict Subnets in the address pool have been
classified into other clients.
3005-3999 - unassigned Unassigned error codes for address
allocation.
4000 - reserved
4001 Update-Fail-No-Res The forwarding table fails to be
delivered because the forwarding resources
are insufficient.
4002 QoS-Update-Success The QoS policy takes effect.
4003 QoS-Update-Sq-Fail Failed to process the queue in the QoS
policy.
4004 QoS-Update-CAR-Fail Processing of the CAR in the QoS
policy fails.
4005 Statistic-Fail-No-Res Statistics processing failed due to
insufficient statistics resources.
4006-4999 - unassigned forwarding table delivery error codes.
5000-4294967295 - reserved
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10. IANA Considerations
This document requires no IANA actions.
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11. Security Considerations
The Service, Control, and Management Interfaces between the CP and UP
might be across the general Internet or other hostile environment.
The ability of an adversary to block or corrupt messages or introduce
spurious messages on any one or more of these interfaces would give
the adversary the ability to stop subscribers from accessing network
services, disrupt existing subscriber sessions, divert traffic, mess
up accounting statistics, and generally cause havoc. Damage would not
necessarily be limited to one or a few subscribers but could disrupt
routing or deny service to one or more instances of the CP or
otherwise cause extensive interference. If the adversary knows the
details of the UP equipment and its forwarding rule capabilities, the
adversary may be able to cause a copy of all user data to be sent to
an address of the adversary's choosing, thus enabling eavesdropping.
Thus, appropriate protections MUST be implemented to provide
integrity, authenticity, and secrecy of traffic over those
interfaces. Whether such protection is used is a network operator
decision. See [RFC6241] for Management Interface / NETCONF security.
Security on the Service Interface is dependent on the tunneling
protocol used which is out of scope for this document. Security for
the Control Interface, over which the S-CUSP protocol flows, is
further discussed below.
S-CUSP messages do not provide security. Thus, if these messages are
exchanged in an environment where security is a concern, that
security MUST be provided by another protocol such as TLS 1.3
[RFC8446] or IPSEC. TLS 1.3 is the mandatory to implement protocol
for interoperability. However, such security protocols need not
always be used and lesser security precautions might be appropriate
because, in some cases, the communication between the CP and UP is in
a benign environment.
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Contributors
Zhouyi Yu
Huawei Technologies
Email: yuzhouyi@huawei.com
Chengguang Niu
Huawei Technologies
Email: chengguang.niu@huawei.com
Zitao Wang
Huawei Technologies
Email: wangzitao@huawei.com
Jun Song
Huawei Technologies
Email: song.jun@huawei.com
Dan Meng
H3C Technologies
No.1 Lixing Center
No.8 guangxun south street, Chaoyang District,
Beijing, 100102
China
Email: mengdan@h3c.com
Hanlei Liu
H3C Technologies
No.1 Lixing Center
No.8 guangxun south street, Chaoyang District,
Beijing, 100102
China
Email: hanlei_liu@h3c.com
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Normative References
[RFC20] Cerf, V., "ASCII format for network interchange", STD 80, RFC
20, DOI 10.17487/RFC0020, October 1969, <https://www.rfc-
editor.org/info/rfc20>.
[RFC793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793,
DOI 10.17487/RFC0793, September 1981, <https://www.rfc-
editor.org/info/rfc793>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI
10.17487/RFC2119, March 1997, <https://www.rfc-
editor.org/info/rfc2119>.
[RFC2661] Townsley, W., Valencia, A., Rubens, A., Pall, G., Zorn, G.,
and B. Palter, "Layer Two Tunneling Protocol "L2TP"", RFC
2661, DOI 10.17487/RFC2661, August 1999, <https://www.rfc-
editor.org/info/rfc2661>.
[RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson,
"Remote Authentication Dial In User Service (RADIUS)", RFC
2865, DOI 10.17487/RFC2865, June 2000, <https://www.rfc-
editor.org/info/rfc2865>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<https://www.rfc-editor.org/info/rfc6241>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119
Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May
2017, <https://www.rfc-editor.org/info/rfc8174>.
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Informative References
[802.1Q] IEEE, "IEEE Standard for Local and metropolitan area
networks / Bridges and Bridged Networks", IEEE Std
802.1Q-2014, 3 November 2013.
[RFC1661] Simpson, W., Ed., "The Point-to-Point Protocol (PPP)", STD
51, RFC 1661, DOI 10.17487/RFC1661, July 1994,
<https://www.rfc-editor.org/info/rfc1661>.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131,
DOI 10.17487/RFC2131, March 1997, <https://www.rfc-
editor.org/info/rfc2131>.
[RFC2516] Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,
and R. Wheeler, "A Method for Transmitting PPP Over
Ethernet (PPPoE)", RFC 2516, DOI 10.17487/RFC2516, February
1999, <https://www.rfc-editor.org/info/rfc2516>.
[RFC2698] Heinanen, J. and R. Guerin, "A Two Rate Three Color
Marker", RFC 2698, DOI 10.17487/RFC2698, September 1999,
<https://www.rfc-editor.org/info/rfc2698>.
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022, DOI
10.17487/RFC3022, January 2001, <https://www.rfc-
editor.org/info/rfc3022>
[RFC3336] Thompson, B., Koren, T., and B. Buffam, "PPP Over
Asynchronous Transfer Mode Adaptation Layer 2 (AAL2)", RFC
3336, DOI 10.17487/RFC3336, December 2002,
<https://www.rfc-editor.org/info/rfc3336>.
[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax Used
to Form Encoding Rules in Various Routing Protocol
Specifications", RFC 5511, DOI 10.17487/RFC5511, April
2009, <https://www.rfc-editor.org/info/rfc5511>.
[RFC7042] Eastlake 3rd, D. and J. Abley, "IANA Considerations and
IETF Protocol and Documentation Usage for IEEE 802
Parameters", BCP 141, RFC 7042, DOI 10.17487/RFC7042,
October 2013, <https://www.rfc-editor.org/info/rfc7042>.
[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
eXtensible Local Area Network (VXLAN): A Framework for
Overlaying Virtualized Layer 2 Networks over Layer 3
Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
<https://www.rfc-editor.org/info/rfc7348>.
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[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205, RFC
7942, DOI 10.17487/RFC7942, July 2016, <https://www.rfc-
editor.org/info/rfc7942>.
[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[TR-384] Broadband Forum, "Cloud Central Office Reference
Architectural Framework", BBF TR-384, 2018.
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Authors' Addresses
Shujun Hu
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing, Beijing 100053
China
Email: hushujun@chinamobile.com
Donald Eastlake, 3rd
Futurewei Technologies
1424 Pro Shop Court
Davenport, FL 33896
USA
Phone: +1-508-333-2270
Email: d3e3e3@gmail.com
Mach (Guoyi) Chen
Huawei Technologies
Huawei Bldg., No. 156 Beiqing Road
Beijing 100095 China
Email: mach.chen@huawei.com
Fengwei Qin
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing, Beijing 100053
China
Email: qinfengwei@chinamobile.com
Zhenqiang Li
China Mobile
32 Xuanwumen West Ave, Xicheng District
Beijing, Beijing 100053
China
Email: lizhenqiang@chinamobile.com
Hu, et al [Page 126]
INTERNET-DRAFT Simple BNG CUSP
Tee Mong Chua
Singapore Telecommunications Limited
31 Exeter Road, #05-04 Comcentre Podium Block
Singapore City 239732
Singapore
Email: teemong@singtel.com
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INTERNET-DRAFT Simple BNG CUSP
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described in the Simplified BSD License.
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