Network Working Group M. Boucadair, Ed.
Internet-Draft D. Binet
Intended status: Informational S. Durel
Expires: October 13, 2014 B. Chatras
France Telecom
T. Reddy
Cisco
B. Williams
Akamai, Inc.
B. Sarikaya
L. Xue
Huawei
April 11, 2014
Host Identification: Use Cases
draft-boucadair-intarea-host-identifier-scenarios-05
Abstract
This document describes a set of scenarios in which host
identification is problematic. The document does not include any
solution-specific discussion.
Status of This Memo
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This Internet-Draft will expire on October 13, 2014.
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Use Case 1: CGN . . . . . . . . . . . . . . . . . . . . . . . 4
4. Use Case 2: A+P . . . . . . . . . . . . . . . . . . . . . . . 4
5. Use Case 3: Application Proxies . . . . . . . . . . . . . . . 5
6. Use Case 4: Open Wi-Fi or Provider Wi-Fi . . . . . . . . . . 6
7. Use Case 5: Policy and Charging Control Architecture . . . . 7
8. Use Case 6: Cellular Networks . . . . . . . . . . . . . . . . 8
9. Use Case 7: Femtocells . . . . . . . . . . . . . . . . . . . 9
10. Use Case 8: Overlay Network . . . . . . . . . . . . . . . . . 10
11. Use Case 9: Emergency Calls . . . . . . . . . . . . . . . . . 12
12. Use Case 10: Traffic Detection Function . . . . . . . . . . . 13
13. Use Case 11: Fixed and Mobile Network Convergence . . . . . . 14
14. Synthesis . . . . . . . . . . . . . . . . . . . . . . . . . . 17
15. Privacy Considerations . . . . . . . . . . . . . . . . . . . 17
16. Security Considerations . . . . . . . . . . . . . . . . . . . 17
17. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18
18. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 18
19. Informative References . . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 20
1. Introduction
The goal of this document is to enumerate use cases which encounter
the issue of uniquely identifying a host among those sharing the same
IP address. Examples of encountered issues in those use cases are:
o Blacklist a misbehaving host without impacting all hosts sharing
the same IP address.
o Enforce a per-subscriber/per-UE policy (e.g., limit access to the
service based on some counters such as volume-based service
offering); enforcing the policy will have impact on all hosts
sharing the same IP address.
o If invoking a service has failed (e.g., wrong login/password), all
hosts sharing the same IP address may not be able to access that
service.
o Need to correlate between the internal address:port and external
address:port to generate and therefore to enforce policies.
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o Query a location server for the location of an emergency caller
based on the source IP address.
It is out of scope of this document to list all the encountered
issues as this is already covered in [RFC6269].
The following use cases are identified:
(1) Carrier Grade NAT (CGN) (Section 3)
(2) A+P (e.g., MAP ) (Section 4)
(3) Application Proxies (Section 5)
(4) Provider Wi-Fi (Section 6)
(5) Policy and Charging Architectures (Section 7)
(6) Cellular Networks (Section 8)
(7) Femtocells (Section 9)
(8) Overlay Networks (e.g., CDNs) (Section 10)
(9) Emergency Calls (Section 11)
(10) Traffic Detection Function (Section 12)
(11) Fixed and Mobile Network Convergence (Section 13)
The analysis of the use cases listed in this document indicates
several root causes for the host identification issue:
1. Presence of address sharing (NAT, A+P, application proxies,
etc.).
2. Use of tunnels between two administrative domains.
3. Combination of address sharing and presence of tunnels in the
path.
2. Scope
It is out of scope of this document to argue in favor or against the
use cases listed in the following sections. The goal is to identify
scenarios the authors are aware of and which share the same issue of
host identification.
This document does not include any solution-specific discussion.
This document can be used as a tool to design solution(s) mitigating
the encountered issues. Describing the use case allows to identify
what is common between the use cases and then would help during the
solution design phase.
The document does not elaborate whether explicit authentication is
enabled or not.
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3. Use Case 1: CGN
Several flavors of stateful CGN have been defined. A non-exhaustive
list is provided below:
1. NAT44 ([RFC6888], [I-D.tsou-stateless-nat44])
2. DS-Lite NAT44 [RFC6333]
3. NAT64 [RFC6146]
4. NPTv6 [RFC6296]
As discussed in [RFC6967], remote servers are not able to distinguish
between hosts sharing the same IP address (Figure 1).
+-----------+
| HOST_1 |----+
+-----------+ | +--------------------+ +------------+
| | |------| server 1 |
+-----------+ +-----+ | | +------------+
| HOST_2 |--| CGN |----| INTERNET | ::
+-----------+ +-----+ | | +------------+
| | |------| server n |
+-----------+ | +--------------------+ +------------+
| HOST_3 |-----+
+-----------+
Figure 1: CGN Reference Architecture
Some of the above referenced CGN use cases will be satisfied by
eventual completion of the transition to IPv6 across the Internet
(e.g., NAT64), but this is not true of all CGN use cases (e.g. NPTv6
[RFC6296]) for which some of the issues discussed in [RFC6269] will
be encountered (e.g., impact on geolocation [RFC6269]). Note, it is
not the intent of this document to advocate in favor or against
NPTv6, but to highlight the complications that may raise when
enabling such function.
4. Use Case 2: A+P
A+P [RFC6346][I-D.ietf-softwire-map][I-D.ietf-softwire-lw4over6]
denotes a flavor of address sharing solutions which does not require
any additional NAT function be enabled in the service provider's
network. A+P assumes subscribers are assigned with the same IPv4
address together with a port set. Subscribers assigned with the same
IPv4 address should be assigned non overlapping port sets. Devices
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connected to an A+P-enabled network should be able to restrict the
IPv4 source port to be within a configured range of ports. To
forward incoming packets to the appropriate host, a dedicated entity
called PRR (Port Range Router, [RFC6346]) is needed (Figure 2).
Similar to the CGN case, the same issue to identify hosts sharing the
same IP address is encountered by remote servers.
+-----------+
| HOST_1 |----+
+-----------+ | +--------------------+ +------------+
| | |------| server 1 |
+-----------+ +-----+ | | +------------+
| HOST_2 |--| PRR |----| INTERNET | ::
+-----------+ +-----+ | | +------------+
| | |------| server n |
+-----------+ | +--------------------+ +------------+
| HOST_3 |-----+
+-----------+
Figure 2: A+P Reference Architecture
5. Use Case 3: Application Proxies
This scenario is similar to the CGN scenario. Remote servers are not
able to distinguish hosts located behind the PROXY. Applying
policies on the perceived external IP address as received from the
PROXY will impact all hosts connected to that PROXY.
Figure 3 illustrates a simple configuration involving a proxy. Note
several (per-application) proxies may be deployed.
+-----------+
| HOST_1 |----+
+-----------+ | +--------------------+ +------------+
| | |------| server 1 |
+-----------+ +-----+ | | +------------+
| HOST_2 |--|PROXY|----| INTERNET | ::
+-----------+ +-----+ | | +------------+
| | |------| server n |
+-----------+ | +--------------------+ +------------+
| HOST_3 |-----+
+-----------+
Figure 3: Proxy Reference Architecture
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In the application proxy scenario, packets/connections must be
received by the proxy regardless of the IP address family in use.
The requirements of this use case are not satisfied by eventual
completion of the transition to IPv6 across the Internet.
6. Use Case 4: Open Wi-Fi or Provider Wi-Fi
In the context of Provider Wi-Fi (WLAN), a dedicated SSID can be
configured and advertised by the RG (Residential Gateway) for
visiting terminals. These visiting terminals can be mobile
terminals, PCs, etc.
Several deployment scenarios are envisaged:
1. Deploy a dedicated node in the service provider's network which
will be responsible to intercept all the traffic issued from
visiting terminals (see Figure 4). This node may be co-located
with a CGN function if private IPv4 addresses are assigned to
visiting terminals. Similar to the CGN case discussed in
Section 3, remote servers may not be able to distinguish visiting
hosts sharing the same IP address (see [RFC6269]).
2. Unlike the previous deployment scenario, IPv4 addresses are
managed by the RG without requiring any additional NAT to be
deployed in the service provider's network for handling traffic
issued from visiting terminals. Concretely, a visiting terminal
is assigned with a private IPv4 address from the IPv4 address
pool managed by the RG. Packets issued form a visiting terminal
are translated using the public IP address assigned to the RG
(see Figure 5). This deployment scenario induces the following
identification concerns:
* The provider is not able to distinguish the traffic belonging
to the visiting terminal from the traffic of the subscriber
owning the RG. This is needed to apply some policies such as:
accounting, DSCP remarking, black list, etc.
* Similar to the CGN case Section 3, a misbehaving visiting
terminal is likely to have some impact on the experienced
service by the subscriber owning the RG (e.g., some of the
issues are discussed in [RFC6269]).
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+-------------+
|Local_HOST_1 |----+
+-------------+ |
| |
+-------------+ +-----+ | +-----------+
|Local_HOST_2 |--| RG |-|--|Border Node|
+-------------+ +-----+ | +----NAT----+
| |
+-------------+ | | Service Provider
|Visiting Host|-----+
+-------------+
Figure 4: NAT enforced in a Service Provider's Node
+-------------+
|Local_HOST_1 |----+
+-------------+ |
| |
+-------------+ +-----+ | +-----------+
|Local_HOST_2 |--| RG |-|--|Border Node|
+-------------+ +-NAT-+ | +-----------+
| |
+-------------+ | | Service Provider
|Visiting Host|-----+
+-------------+
Figure 5: NAT located in the RG
7. Use Case 5: Policy and Charging Control Architecture
This issue is related to the framework defined in [TS23.203] when a
NAT is located between the PCEF (Policy and Charging Enforcement
Function) and the AF (Application Function) as shown in Figure 6.
The main issue is: PCEF, PCRF and AF all receive information bound to
the same UE( User Equipment) but without being able to correlate
between the piece of data visible for each entity. Concretely,
o PCEF is aware of the IMSI (International Mobile Subscriber
Identity) and an internal IP address assigned to the UE.
o AF receives an external IP address and port as assigned by the NAT
function.
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o PCRF is not able to correlate between the external IP address/port
assigned by the NAT (received from the AF) and the internal IP
address and IMSI of the UE (received from the PCEF).
+------+
| PCRF |-----------------+
+------+ |
| |
+----+ +------+ +-----+ +-----+
| UE |------| PCEF |---| NAT |----| AF |
+----+ +------+ +-----+ +-----+
Figure 6: NAT located between AF and PCEF
This scenario can be generalized as follows (Figure 7):
o Policy Enforcement Point (PEP, [RFC2753])
o Policy Decision Point (PDP, [RFC2753])
+------+
| PDP |-----------------+
+------+ |
| |
+----+ +------+ +-----+ +------+
| UE |------| PEP |---| NAT |----|Server|
+----+ +------+ +-----+ +------+
Figure 7: NAT located between PEP and Server
Note that an issue is encountered to enforce per-UE policies when the
NAT is located before the PEP function (see Figure 8):
+------+
| PDP |------+
+------+ |
| |
+----+ +------+ +-----+ +------+
| UE |------| NAT |---| PEP |----|Server|
+----+ +------+ +-----+ +------+
Figure 8: NAT located before PEP
8. Use Case 6: Cellular Networks
Cellular operators allocate private IPv4 addresses to mobile
terminals and deploy NAT44 function, generally co-located with
firewalls, to access to public IP services. The NAT function is
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located at the boundaries of the PLMN (Public Land Mobile Network).
IPv6-only strategy, consisting in allocating IPv6 prefixes only to
mobile terminals, is considered by various operators. A NAT64
function is also considered in order to preserve IPv4 service
continuity for these customers.
These NAT44 and NAT64 functions bring some issues very similar to
those mentioned in Figure 1 and Section 7. This issue is
particularly encountered if policies are to be applied on the Gi
interface: a private IP address is assigned to the mobile terminals,
there is no correlation between the internal IP address and the
external address:port assigned by the NAT function, etc.
9. Use Case 7: Femtocells
This use case can be seen as a combination of the use cases described
in Section 6 and Section 7.
The reference architecture is shown in Figure 8.
+---------------------------+
| +----+ +--------+ +----+ | +-----------+ +-------------------+
| | UE | | Stand- |<=|====|=|===|===========|==|=>+--+ +--+ |
| +----+ | alone | | RG | | | | | | | | | Mobile |
| | FAP | +----+ | | | | |S | |F | Network|
| +--------+ (NAPT) | | Broadband | | |e | |A | |
+---------------------------+ | Fixed | | |G |-|P | +-----+|
| Network | | |W | |G |-| Core||
+---------------------------+ | (BBF) | | | | |W | | Ntwk||
| +----+ +------------+ | | | | | | | | +-----+|
| | UE | | Integrated |<====|===|===========|==|=>+--+ +--+ |
| +----+ | FAP (NAPT) | | +-----------+ +-------------------+
| +------------+ |
+---------------------------+
<=====> IPsec tunnel
CoreNtwk Core Network
FAPGW FAP Gateway
SeGW Security Gateway
Figure 9: Femtocell Reference Architecture
UE is connected to the FAP at the residential gateway (RG), routed
back to 3GPP Evolved Packet Core (EPC). UE is assigned IPv4 address
by the Mobile Network. Mobile operator's FAP leverages the IPsec
IKEv2 to interconnect FAP with the SeGW over the BBF network. Both
the FAP and the SeGW are managed by the mobile operator which may be
a different operator for the BBF network.
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An investigated scenario is the mobile operator to pass on its mobile
subscriber's policies to the BBF to support traffic policy control .
But most of today's broadband fixed networks are relying on the
private IPv4 addressing plan (+NAPT) to support its attached devices
including the mobile operator's FAP. In this scenario, the mobile
network needs to:
o determine the FAP's public IPv4 address to identify the location
of the FAP to ensure its legitimacy to operate on the license
spectrum for a given mobile operator prior to the FAP be ready to
serve its mobile devices.
o determine the FAP's pubic IPv4 address together with the
translated port number of the UDP header of the encapsulated IPsec
tunnel for identifying the UE's traffic at the fixed broadband
network.
o determine the corresponding FAP's public IPv4 address associated
with the UE's inner-IPv4 address which is assigned by the mobile
network to identify the mobile UE to allow the PCRF to retrieve
the special UE's policy (e.g., QoS) to be passed onto the
Broadband Policy Control Function (BPCF) at the BBF network.
SeGW would have the complete knowledge of such mapping, but the
reasons for unable to use SeGW for this purpose is explained in
"Problem Statements" (section 2 of [I-D.so-ipsecme-ikev2-cpext]).
This use case involves PCRF/BPCF but it is valid in other deployment
scenarios making use of AAA servers.
The issue of correlating the internal IP address and the public IP
address is valid even if there is no NAT in the path.
10. Use Case 8: Overlay Network
An overlay network is a network of machines distributed throughout
multiple autonomous systems within the public Internet that can be
used to improve the performance of data transport (see Figure 10).
IP packets from the sender are delivered first to one of the machines
that make up the overlay network. That machine then relays the IP
packets to the receiver via one or more machines in the overlay
network, applying various performance enhancement methods.
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+------------------------------------+
| |
| INTERNET |
| |
+-----------+ | +------------+ |
| HOST_1 |-----| OVRLY_IN_1 |-----------+ |
+-----------+ | +------------+ | |
| | |
+-----------+ | +------------+ +-----------+ | +--------+
| HOST_2 |-----| OVRLY_IN_2 |-----| OVRLY_OUT |-----| SERVER |
+-----------+ | +------------+ +-----------+ | +--------+
| | |
+-----------+ | +------------+ | |
| HOST_3 |-----| OVRLY_IN_3 |-----------+ |
+-----------+ | +------------+ |
| |
+------------------------------------+
Figure 10: Overlay Network Reference Architecture
Such overlay networks are used to improve the performance of content
delivery [IEEE1344002]. Overlay networks are also used for peer-to-
peer data transport [RFC5694], and they have been suggested for use
in both improved scalability for the Internet routing infrastructure
[RFC6179] and provisioning of security services (intrusion detection,
anti-virus software, etc.) over the public Internet [IEEE101109].
In order for an overlay network to intercept packets and/or
connections transparently via base Internet connectivity
infrastructure, the overlay ingress and egress hosts (OVERLAY_IN and
OVERLAY_OUT) must be reliably in-path in both directions between the
connection-initiating HOST and the SERVER. When this is not the
case, packets may be routed around the overlay and sent directly to
the receiving host.
For public overlay networks, where the ingress and/or egress hosts
are on the public Internet, packet interception commonly uses network
address translation for the source (SNAT) or destination (DNAT)
addresses in such a way that the public IP addresses of the true
endpoint hosts involved in the data transport are invisible to each
other (see Figure 11). For example, the actual sender and receiver
may use two completely different pairs of source and destination
addresses to identify the connection on the sending and receiving
networks in cases where both the ingress and egress hosts are on the
public Internet.
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ip hdr contains: ip hdr contains:
SENDER -> src = sender --> OVERLAY --> src = overlay2 --> RECEIVER
dst = overlay1 dst = receiver
Figure 11: NAT operations in an Overlay Network
In this scenario, the remote server is not able to distinguish among
hosts using the overlay for transport. In addition, the remote
server is not able to determine the overlay ingress point being used
by the host, which can be useful for diagnosing host connectivity
issues.
In some of the above referenced use cases, IP packets traverse the
overlay network fundamentally unchanged, with the overlay network
functioning much like a CGN (Section 3). In other cases, connection-
oriented data flows (e.g. TCP) are terminated by the overlay in order
to perform object caching and other such transport and application
layer optimizations, similar to the proxy scenario (Section 5). In
both cases, address sharing is a requirement for packet/connection
interception, which means that the requirements for this use case are
not satisfied by the eventual completion of the transition to IPv6
across the Internet.
More details about this use case are provided in
[I-D.williams-overlaypath-ip-tcp-rfc].
11. Use Case 9: Emergency Calls
Voice service providers (VSPs) operating under certain jurisdictions
are required to route emergency calls from their subscribers and have
to include information about the caller's location in signaling
messages they send towards PSAPs (Public Safety Answering Points,
[RFC6443]), via an Emergency Service Routing Proxy (ESRP, [RFC6443]).
This information is used both for the determination of the correct
PSAP and to reveal the caller's location to the selected PSAP.
In many countries, regulation bodies require that this information be
provided by the network rather than the user equipment, in which case
the VSP needs to retrieve this information (by reference or by value)
from the access network where the caller is attached.
This requires the VSP call server receiving an emergency call request
to identify the relevant access network and to query a Location
Information Server (LIS) in this network using a suitable look-up
key. In the simplest case, the source IP address of the IP packet
carrying the call request is used both for identifying the access
network (thanks to a reverse DNS query) and as a look-up key to query
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the LIS. Obviously the user-id as known by the VSP (e.g., telephone
number, or email-formatted URI) can't be used as it is not known by
the access network.
The above mechanism is broken when there is a NAT between the user
and the VSP and/or if the emergency call is established over a VPN
tunnel (e.g., an employee remotely connected to a company VoIP server
through a tunnel wishes to make an emergency call). In such cases,
the source IP address received by the VSP call server will identity
the NAT or the address assigned to the caller equipment by the VSP
(i.e., the address inside the tunnel). This is similar to the CGN
case (Section 3) and overlay network case (Section 10) and applies
irrespective of the IP versions used on both sides of the NAT and/or
inside and outside the tunnel.
Therefore, the VSP needs to receive an additional piece of
information that can be used to both identify the access network
where the caller is attached and query the LIS for his/her location.
This would require the NAT or the Tunnel Endpoint to insert this
extra information in the call requests delivered to the VSP call
servers. For example, this extra information could be a combination
of the local IP address assigned by the access network to the
caller's equipment with some form of identification of this access
network.
However, because it shall be possible to setup an emergency call
regardless of the actual call control protocol used between the user
and the VSP (e.g., SIP [RFC3261], IAX [RFC5456], tunneled over HTTP,
or proprietary protocol, possibly encrypted), this extra information
has to be conveyed outside the call request, in the header of lower
layers protocols.
12. Use Case 10: Traffic Detection Function
Operators expect that the traffic subject to the packet inspection is
routed via the Traffic Detection Function (TDF) function as
requirement specified in [TS29.212], otherwise, the traffic may
bypass the TDF. This assumption only holds if it is possible to
identify individual UEs behind NA(P)T which may be deployed into the
RG in fixed broadband network, shown in Figure 12. As a result,
additional mechanisms are needed to enable this requirement.
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+--------+
| |
+-------+ PCRF |
| | |
| +--------+
+--------+ +--------+ +--------+ +----+----+
| | | | | +-----+ |
| ------------------------------------------------------------------
| | | | | | | TDF | / \
| ******************************************************************
| | | +-------+ | | | Service
| | | | | | | \ /
| | | | | | | +--------+
| | | | | | +--------+ PDN |
| ********---------**********--------************------------******* |
| UE | | RG | | BNG +------------------+ Gateway|
+--------+ +--------+ +--------+ +--------+
Legends:
--------- 3GPP UE User Plane Traffic Offloaded subject to packet
inspection
********* 3GPP UE User Plane Traffic Offloaded not subject to packet
inspection
*****---- 3GPP UE User Plane Traffic Home Routed
Figure 12: UE's Traffic Routed with TDF
13. Use Case 11: Fixed and Mobile Network Convergence
In the Policy for Convergence of Fixed Mobile Convergence (FMC)
scenario, the fixed broadband network must partner with the mobile
network to acquire the policies for the terminals or hosts attaching
to the fixed broadband network, shown in Figure 13 so that host-
specific QoS and accounting policies can be applied.
A UE is connected to the RG, routed back to the mobile network. The
mobile operator's PCRF needs to maintain the interconnect with the
Broadband Policy Control Function (BPCF) in the BBF network for PCC
(Section 7). The hosts (i.e., UEs) attaching to fixed broadband
network with a NA(P)T deployed should be identified. Based on the UE
identification, the BPCF to deploy policy rules in the fixed
broadband network can acquire the associated policy rules of the
identified UE from the PCRF in the mobile network. But in the fixed
broadband network, private IPv4 address is supported. The similar
requirements are raised in this use case as Section 9.
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+------------------------------+ +-------------+
| | | |
| +------+ | | +------+ |
| | BPCF +---+---+-+ PCRF | |
| +--+---+ | | +---+--+ |
+-------+ | | | | | |
|HOST_1 |Private IP1 +--+---+ | | +---+--+ |
+-------+ | +----+ | | | | | | |
| | RG | | | | | | | |
| |with+-------------+ BNG +--------+ PGW | |
+-------+ | | NAT| | | | | | | |
|HOST_2 | | +----+ | | | | | | |
+-------+Private IP2 +------+ | | +------+ |
| | | |
| | | |
| Fixed | | Mobile |
| Broadband | | Network |
| Network | | |
| | | |
+------------------------------+ +-------------+
Figure 13: Reference Architecture for Policy for Convergence in Fixed
and Mobile Network Convergence (1)
In IPv6 network, the similar issues exists when the IPv6 prefix is
sharing between multiple UEs attaching to the RG (see Figure 14).
The case applies when RG is assigned a single prefix, the home
network prefix, e.g. using DHCPv6 Prefix Delegation [RFC3633] with
the edge router, BNG acting as the Delegating Router (DR). RG uses
the home network prefix in the address configuration using stateful
(DHCPv6) or stateless address assignment (SLAAC) techniques.
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+------------------------------+ +-------------+
| | | |
| | | +------+ |
| +-------------+ PCRF | |
| | | | +---+--+ |
+-------+ | | | | | |
|HOST_1 |--+ +--+---+ | | +---+--+ |
+-------+ | +----+ | | | | | | |
| | RG | | | | | | | |
| | +------------+ BNG +---------+ PGW | |
+-------+ | | | | | | | | | |
|HOST_2 |--+ +----+ | | | | | | |
+-------+ | +------+ | | +------+ |
| | | |
| | | |
| Fixed | | Mobile |
| Broadband | | Network |
| Network | | |
| | | |
+------------------------------+ +-------------+
Figure 14: Reference Architecture for Policy for Convergence in Fixed
and Mobile Network Convergence (2)
BNG acting as PCEF initiates an IP Connectivity Access Network (IP-
CAN) session with the policy server, a.k.a. Policy and Charging Rules
Function (PCRF), to receive the Quality of Service (QoS) parameters
and Charging rules. BNG provides to the PCRF the IPv6 Prefix
assigned to the host, in this case the home network prefix and an ID
which in this case has to be equal to the RG specific home network
line ID.
HOST_1 in Figure 14 creates an 128-bit IPv6 address using this prefix
and adding its interface id. Having completed the address
configuration, the host can start communication with a remote hosts
over Internet. However, no specific IP-CAN session can be assigned
to HOST_1, and consequently the QoS and accounting performed will be
based on RG subscription.
Another host, e.g. HOST_2, attaches to RG and also establishes an
IPv6 address using the home network prefix. Edge router, the BNG, is
not involved with this and all other such address assignments.
This leads to the case where no specific IP-CAN session/sub-session
can be assigned to the hosts, HOST_1, HOST_2, etc., and consequently
the QoS and accounting performed can only be based on RG subscription
and not host specific. Therefore IPv6 prefix sharing in Policy for
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Convergence scenario leads to similar issues as the address sharing
as it has been explained in the previous use cases in this document.
14. Synthesis
The following table shows whether each use case is valid for IPv4/
IPv6 and if it is within one single administrative domain or span
multiple domains.
+-------------------+------+-------------+-----------------------+
| Use Case | IPv4 | IPv6 | Single Administrative |
| | |------+------| Domain |
| | |Client|Server| |
+-------------------+------+------+------+-----------------------+
| CGN | Yes |Yes(1)| No | No |
| A+P | Yes | No | No | No |
| Application Proxy | Yes |Yes(2)|Yes(2)| No |
| Provider Wi-Fi | Yes | No | No | Yes |
| PCC | Yes |Yes(1)| No | Yes |
| Femtocells | Yes | No | No | No |
| Cellular Networks | Yes |Yes(1)| No | Yes |
| Overlay Networks | Yes |Yes(3)|Yes(3)| No |
| Emergency Calls | Yes | Yes |Yes | No |
| TDF | Yes | Yes | No | Yes |
| FMC | Yes |Yes(1)| No | No |
+-------------------+------+------+------------------------------+
Notes:
(1) e.g., NAT64
(2) A proxy can use IPv6 for the communication leg with the server
or the application client.
(3) This use case is a combination of CGN and Application Proxies.
15. Privacy Considerations
Privacy-related considerations that apply to means to reveal a host
identified are discussed in [RFC6967]. This document does not
introduce additional privacy issues than those discussed in
[RFC6967].
16. Security Considerations
This document does not define an architecture nor a protocol; as such
it does not raise any security concern. Host identifier related
security considerations are discussed in [RFC6967].
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17. IANA Considerations
This document does not require any action from IANA.
18. Acknowledgments
Many thanks to F. Klamm, D. Wing, and D. von Hugo for their review.
Figure 8 and part of the text in Section 9 are inspired from
[I-D.so-ipsecme-ikev2-cpext].
19. Informative References
[I-D.ietf-softwire-lw4over6]
Cui, Y., Qiong, Q., Boucadair, M., Tsou, T., Lee, Y., and
I. Farrer, "Lightweight 4over6: An Extension to the DS-
Lite Architecture", draft-ietf-softwire-lw4over6-08 (work
in progress), March 2014.
[I-D.ietf-softwire-map]
Troan, O., Dec, W., Li, X., Bao, C., Matsushima, S.,
Murakami, T., and T. Taylor, "Mapping of Address and Port
with Encapsulation (MAP)", draft-ietf-softwire-map-10
(work in progress), January 2014.
[I-D.so-ipsecme-ikev2-cpext]
So, T., "IKEv2 Configuration Payload Extension for Private
IPv4 Support for Fixed Mobile Convergence", draft-so-
ipsecme-ikev2-cpext-02 (work in progress), June 2012.
[I-D.tsou-stateless-nat44]
Tsou, T., Liu, W., Perreault, S., Penno, R., and M. Chen,
"Stateless IPv4 Network Address Translation", draft-tsou-
stateless-nat44-02 (work in progress), October 2012.
[I-D.williams-overlaypath-ip-tcp-rfc]
Williams, B., "Overlay Path Option for IP and TCP", draft-
williams-overlaypath-ip-tcp-rfc-04 (work in progress),
June 2013.
[IEEE101109]
Salah, K., Calero, J., Zeadally, S., Almulla, S., and M.
ZAaabi, "Using Cloud Computing to Implement a Security
Overlay Network, IEEE Security & Privacy, 21 June 2012.
IEEE Computer Society Digital Library.", June 2012.
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[IEEE1344002]
Byers, J., Considine, J., Mitzenmacher, M., and S. Rost,
"Informed content delivery across adaptive overlay
networks: IEEE/ACM Transactions on Networking, Vol 12,
Issue 5, ppg 767-780", October 2004.
[RFC2753] Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework
for Policy-based Admission Control", RFC 2753, January
2000.
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
[RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
Host Configuration Protocol (DHCP) version 6", RFC 3633,
December 2003.
[RFC5456] Spencer, M., Capouch, B., Guy, E., Miller, F., and K.
Shumard, "IAX: Inter-Asterisk eXchange Version 2", RFC
5456, February 2010.
[RFC5694] Camarillo, G. and IAB, "Peer-to-Peer (P2P) Architecture:
Definition, Taxonomies, Examples, and Applicability", RFC
5694, November 2009.
[RFC6146] Bagnulo, M., Matthews, P., and I. van Beijnum, "Stateful
NAT64: Network Address and Protocol Translation from IPv6
Clients to IPv4 Servers", RFC 6146, April 2011.
[RFC6179] Templin, F., "The Internet Routing Overlay Network
(IRON)", RFC 6179, March 2011.
[RFC6269] Ford, M., Boucadair, M., Durand, A., Levis, P., and P.
Roberts, "Issues with IP Address Sharing", RFC 6269, June
2011.
[RFC6296] Wasserman, M. and F. Baker, "IPv6-to-IPv6 Network Prefix
Translation", RFC 6296, June 2011.
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", RFC 6333, August 2011.
[RFC6346] Bush, R., "The Address plus Port (A+P) Approach to the
IPv4 Address Shortage", RFC 6346, August 2011.
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[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
"Framework for Emergency Calling Using Internet
Multimedia", RFC 6443, December 2011.
[RFC6888] Perreault, S., Yamagata, I., Miyakawa, S., Nakagawa, A.,
and H. Ashida, "Common Requirements for Carrier-Grade NATs
(CGNs)", BCP 127, RFC 6888, April 2013.
[RFC6967] Boucadair, M., Touch, J., Levis, P., and R. Penno,
"Analysis of Potential Solutions for Revealing a Host
Identifier (HOST_ID) in Shared Address Deployments", RFC
6967, June 2013.
[TS23.203]
3GPP, , "Policy and charging control architecture",
September 2012.
[TS29.212]
3GPP, , "Policy and Charging Control (PCC); Reference
Points", December 2013.
Authors' Addresses
Mohamed Boucadair (editor)
France Telecom
Rennes 35000
France
Email: mohamed.boucadair@orange.com
David Binet
France Telecom
Rennes
France
Email: david.binet@orange.com
Sophie Durel
France Telecom
Rennes
France
Email: sophie.durel@orange.com
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Bruno Chatras
France Telecom
Paris
France
Email: bruno.chatras@orange.com
Tirumaleswar Reddy
Cisco Systems, Inc.
Cessna Business Park, Varthur Hobli
Sarjapur Marathalli Outer Ring Road
Bangalore, Karnataka 560103
India
Email: tireddy@cisco.com
Brandon Williams
Akamai, Inc.
Cambridge MA
USA
Email: brandon.williams@akamai.com
Behcet Sarikaya
Huawei
5340 Legacy Dr. Building 3,
Plano, TX 75024
USA
Email: behcet.sarikaya@huawei.com
Li Xue
Huawei
Beijing
China
Email: xueli@huawei.com
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