PCE Working Group A. Wang
Internet-Draft China Telecom
Intended status: Standards Track B. Khasanov
Expires: April 23, 2021 S. Fang
R. Tan
Huawei Technologies,Co.,Ltd
C. Zhu
ZTE Corporation
October 20, 2020
PCEP Extension for Native IP Network
draft-ietf-pce-pcep-extension-native-ip-09
Abstract
This document defines the Path Computation Element Communication
Protocol (PCEP) extension for Central Control Dynamic Routing (CCDR)
based application in Native IP network. The scenario and framework
of CCDR in native IP is described in [RFC8735] and
[I-D.ietf-teas-pce-native-ip]. This draft describes the key
information that is transferred between Path Computation Element
(PCE) and Path Computation Clients (PCC) to accomplish the End to End
(E2E) traffic assurance in Native IP network under central control
mode.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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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."
This Internet-Draft will expire on April 23, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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(https://trustee.ietf.org/license-info) in effect on the date of
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Capability Advertisemnt . . . . . . . . . . . . . . . . . . . 3
4.1. Open message . . . . . . . . . . . . . . . . . . . . . . 3
5. PCEP messages . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. The PCInitiate message . . . . . . . . . . . . . . . . . 4
5.2. The PCRpt message . . . . . . . . . . . . . . . . . . . . 5
6. PCECC Native IP TE Procedures . . . . . . . . . . . . . . . . 6
6.1. BGP Session Establishment Procedures . . . . . . . . . . 6
6.2. Explicit Route Establish Procedures . . . . . . . . . . . 9
6.3. BGP Prefix Advertisement Procedures . . . . . . . . . . . 12
7. New PCEP Objects . . . . . . . . . . . . . . . . . . . . . . 13
7.1. CCI Object . . . . . . . . . . . . . . . . . . . . . . . 13
7.2. BGP Peer Info Object . . . . . . . . . . . . . . . . . . 14
7.3. Explicit Peer Route Object . . . . . . . . . . . . . . . 17
7.4. Peer Prefix Association Object . . . . . . . . . . . . . 18
8. New Error-Types and Error-Values Defined . . . . . . . . . . 19
9. Management Consideration . . . . . . . . . . . . . . . . . . 20
10. Security Considerations . . . . . . . . . . . . . . . . . . . 21
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
11.1. PCEP Object Types . . . . . . . . . . . . . . . . . . . 21
12. Contributor . . . . . . . . . . . . . . . . . . . . . . . . . 21
13. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 21
14. Normative References . . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction
Generally, Multiprotocol Label Switching Traffic Engineering (MPLS-
TE) requires the corresponding network devices support Multiprotocol
Label Switching (MPLS) or Resource ReSerVation Protocol (RSVP)/Label
Distribution Protocol (LDP) technologies to assure the End-to-End
(E2E) traffic performance. But in native IP network, there will be
no such signaling protocol to synchronize the action among different
network devices. It is necessary to use the central control mode
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that described in [RFC8283] to correlate the forwarding behavior
among different network devices. Draft [I-D.ietf-teas-pce-native-ip]
describes the architecture and solution philosophy for the E2E
traffic assurance in Native IP network via Multi Border Gateway
Protocol (BGP) solution. This draft describes the corresponding Path
Computation Element Communication Protocol (PCEP) extensions to
transfer the key information about BGP peer info, peer prefix
association and the explicit peer route on on-path routers.
2. Conventions used in this document
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.
3. Terminology
This document uses the following terms defined in [RFC5440]: PCE,
PCEP
The following terms are defined in this document:
o CCDR: Central Control Dynamic Routing
o E2E: End to End
o BPI: BGP Peer Info
o EPR: Explicit Peer Route
o PPA: Peer Prefix Association
o QoS: Quality of Service
4. Capability Advertisemnt
4.1. Open message
During the PCEP Initialization Phase, PCEP Speakers (PCE or PCC)
advertise their support of Native IP extensions.
This document defines a new Path Setup Type (PST) [RFC8408] for
Native-IP, as follows:
o PST = TBD1: Path is a Native IP path as per
[I-D.ietf-teas-pce-native-ip].
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A PCEP speaker MUST indicate its support of the function described in
this document by sending a PATH-SETUP-TYPE-CAPABILITY TLV in the OPEN
object with this new PST included in the PST list.
[I-D.ietf-pce-pcep-extension-for-pce-controller] defined the PCECC-
CAPABILITY sub-TLV to exchange information about their PCECC
capability. A new flag is defined in PCECC-CAPABILITY sub-TLV for
Native IP.
N (NATIVE-IP-TE-CAPABILITY - 1 bit - TBD2): If set to 1 by a PCEP
speaker, it indicates that the PCEP speaker is capable for TE in
Native IP network as specified in this document. The flag MUST be
set by both the PCC and PCE in order to support this extension.
5. PCEP messages
PCECC Native IP TE solution utilizing the existing PCE LSP Initate
Request message(PCInitiate)[RFC8281], and PCE Report message(PCRpt)
[RFC8281] to accomplish the multi BGP sessions establishment, end to
end TE path deployment, and route prefixes advertisement among
different BGP sessions. A new PST for Native-IP is used to indicate
the path setup based on TE in Native IP networks.
The extended PCInitiate message described in
[I-D.ietf-pce-pcep-extension-for-pce-controller] is used to download
or cleanup central controller's instructions (CCIs).
[I-D.ietf-pce-pcep-extension-for-pce-controller] specify an object
called CCI for the encoding of central controller's instructions.
This document specify a new CCI object-type for Native IP. The PCEP
messages are extended in this document to handle the PCECC operations
for Native IP. Three new PCEP Objects (BGP Peer Info (BPI) Object,
Explicit Peer Route (EPR) Object and Peer Prefix Association (PPA)
Object) are defined in this document. Refer toSection 7 for detail
object definitions.
5.1. The PCInitiate message
The PCInitiate Message defined in [RFC8281] and extended in
[I-D.ietf-pce-pcep-extension-for-pce-controller] is further extended
to support Native-IP CCI.
The format of the extended PCInitiate message is as follows:
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<PCInitiate Message> ::= <Common Header>
<PCE-initiated-lsp-list>
Where:
<Common Header> is defined in [RFC5440]
<PCE-initiated-lsp-list> ::= <PCE-initiated-lsp-request>
[<PCE-initiated-lsp-list>]
<PCE-initiated-lsp-request> ::=
(<PCE-initiated-lsp-instantiation>|
<PCE-initiated-lsp-deletion>|
<PCE-initiated-lsp-central-control>)
<PCE-initiated-lsp-central-control> ::= <SRP>
(<LSP>
<cci-list>)|
((<BPI>|<EPR>|<PPA>)
<CCI>)
<cci-list> ::= <CCI>
[<cci-list>]
Where:
<cci-list> is as per
[I-D.ietf-pce-pcep-extension-for-pce-controller].
<PCE-initiated-lsp-instantiation> and
<PCE-initiated-lsp-deletion> are as per
[RFC8281].
The LSP and SRP object is defined in [RFC8231].
When PCInitiate message is used create Native IP instructions, the
SRP and CCI objects MUST be present. The error handling for missing
SRP or CCI object is as per
[I-D.ietf-pce-pcep-extension-for-pce-controller]. Further either one
of BPI, EPR, or PPA object MUST be present. If none of them are
present, the receiving PCC MUST send a PCErr message with Error-
type=6 (Mandatory Object missing) and Error-value=TBD (Native IP
object missing).
To cleanup the SRP object must set the R (remove) bit.
5.2. The PCRpt message
The PCRpt message is used to acknowledge the Native-IP instructions
received from the central controller (PCE).
The format of the PCRpt message is as follows:
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<PCRpt Message> ::= <Common Header>
<state-report-list>
Where:
<state-report-list> ::= <state-report>[<state-report-list>]
<state-report> ::= (<lsp-state-report>|
<central-control-report>)
<lsp-state-report> ::= [<SRP>]
<LSP>
<path>
<central-control-report> ::= [<SRP>]
(<LSP>
<cci-list>)|
((<BPI>|<EPR>|<PPA>)
<CCI>)
Where:
<path> is as per [RFC8231] and the LSP and SRP object are
also defined in [RFC8231].
The error handling for missing CCI object is as per
[I-D.ietf-pce-pcep-extension-for-pce-controller]. Further either one
of BPI, EPR, or PPA object MUST be present. If none of them are
present, the receiving PCE MUST send a PCErr message with Error-
type=6 (Mandatory Object missing) and Error-value=TBD ( Native IP
object missing).
6. PCECC Native IP TE Procedures
The detail procedures for the TE in native IP environment are
described in the following sections.
6.1. BGP Session Establishment Procedures
The procedures for establishing the BGP session between two peers is
shown below, using the PCInitiate and PCRpt message pair.
The PCInitiate message should be sent to PCC which acts as BGP
routers and route reflector. In the example in Figure 1, it should
be sent to R1(M1), R3(M2 & M3) and R7(M4), when R3 acts as RR.
When PCC receives the BPI and CCI object (with the R bit set to 0 in
SRP object) in PCInitiate message, the PCC should try to establish
the BGP session with the indicated Peer AS and Local/Peer IP address.
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When PCC creates successfully the BGP session that is indicated by
the associated information, it should report the result via the PCRpt
messages, with BPI object included, and the corresponding SRP and CCI
object.
When PCC receives this message with the R bit set to 1 in SRP object
in PCInitiate message, the PCC should clear the BGP session that
indicated by the BPI object.
When PCC clears successfully the specified BGP session, it should
report the result via the PCRpt message, with the BPI object
included, and the corresponding SRP and CCI object.
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M2 PCInitiate Message: M3 PCInitiate Message:
CC-ID=X3(Symbolic Path Name=Class A) CC-ID=X3(Symbolic Path Name=Class A)
BPI Object(Local IP=R3_A, Peer IP=R1_A) BPI Object(Local IP=R3_A, Peer IP=R7_A)
M2-R PCRpt Message: M3-R PCRpt Message:
CC-ID=X3 CC-ID=X3
BPI Object(Local IP=R3_A, Peer IP=R1_A) BPI Object(Local IP=R3_A, Peer IP=R7_A)
^ ^
| |
+------------------------------------^------------------+
|
|
|
| +------------------+
M1 PCInitiate Message: +----------+ PCE +-----------+
CC-ID=X1(Symbolic Path Name=Class A) | | +--------^---------+ |
BPI Object(Local IP=R1_A, Peer IP=R3_A) | | | |
| | | |
<------+ +-------------+ +---+
M1-R PCRpt Message: | | | |
CC-ID=X1 | +v-+ | |
BPI Object(Local IP=R1_A, Peer IP=R3_A +------------------+R3+-------------------+ | )
| +--+ | |
| | |
+v-+ +--+ +--+ +-v+ |
|R1+----------+R5+----------+R6+---------+R7| |
++-+ +--+ +--+ +-++ |
M4 PCInitiate Message: | | |
CC-ID=X7(Symbolic Path Name=Class A) | | |
BPI Object(Local IP=R7_A,Peer IP=R3_A) | +--+ +--+ | |
+------------+R2+----------+R4+-----------+ |
|
M4-R PCRpt Message: |
CC-ID=X7 <----------------------------------------------------+
BPI Object(Local IP=R3_A, Peer IP=R1_A)
Figure 1: BGP Session Establishment Procedures(R3 act as RR)
If the PCC cannot establish the BGP session that required by this
object, it should report the error values with the newly defined
error type(Error-type=TBD) and error value(Error-Value=01 or 02),
which is indicated in Section 8
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6.2. Explicit Route Establish Procedures
The detail procedures for the explicit route establishment procedures
is shown below, using PCInitiate and PCRpt message pair.
The PCInitiate message should be sent to the on-path routers
respectively. In the example, for explicit route from R1 to R7, the
PCInitiate message should be sent to R1(M1), R2(M2) and R4(M3), as
shown in Figure 2. For explicit route from R7 to R1, the PCInitiate
message should be sent to R7(M1), R4(M2) and R2(M3), as shown in
Figure 3..
When PCC receives the EPR and the CCI object (with the R bit set to 0
in SRP object) in PCInitiate message, the PCC should install the
explicit route to the the peer.
When PCC install successfully the explicit route to the peer, it
should report the result via the PCRpt messages, with EPR object
included, and the corresponding SRP and CCI object.
When PCC receives the EPR and the CCI object with the R bit set to 1
in SRP object in PCInitiate message, the PCC should clear the
explicit route to the peer that indicated by the EPR object.
When PCC clear successfully the explicit route that indicated by this
object, it should report the result via the PCRpt message, with the
EPR object included, and the corresponding SRP and CCI object.
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+------------------+
M1 PCInitiate Message: +----------+ PCE +-----------+
CC-ID=X1(Symbolic Path Name=Class A) | +----^---^---^-----+ |
EPR Object(Peer Address=R7_A | | | | |
Next Hop=R2_A) | | | | |
| | | | |
M1-R PCRpt Message: <---------------+ | | | |
CC-ID=X1 | | +v-+ | |
EPR Object(Peer Address=R7_A +------------+ +---+R3+-------------------+ )
Next Hop=R2_A) | | +--+ | |
| | | |
+v-+ +--+ | | +--+ +-v+
|R1+------+R5++ +----------------+R6+----+R7|
++-+ +--+ | | +--+ +-++
| | | |
M2 PCInitiate Message | +---+ +---+ |
CC-ID=X2(Symbolic Path Name=Class A) | +v-+ | | +v-+ |
EPR Object(Peer Address=R7_A +----------+R2+-+ +--------+R4+-----------+
Next Hop=R4_A) | |
| |
M2-R PCRpt Message | |
CC-ID=X2(Symbolic Path Name=Class A) <----------------------+ |
EPR Object(Peer Address=R7_A |
Next Hop=R4_A) |
v
M3 PCInitiate Message
CC-ID=X4(Symbolic Path Name=Class A)
EPR Object(Peer Address=R7_A
Next Hop=R7_A)
M3-R PCRpt Message
CC-ID=X4(Symbolic Path Name=Class A)
EPR Object(Peer Address=R7_A
Next Hop=R7_A)
Figure 2: Explicit Route Establish Procedures(From R1 to R7)
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-------------------------------------------------------------------------+
| |
v +------------------+ |
M1 PCInitiate Message: +----------+ PCE +-----+-----+
CC-ID=X7(Symbolic Path Name=Class A) | +----^---^---^-----+ |
EPR Object(Peer Address=R1_A | | | | |
Next Hop=R4_A) | | | | |
| | | | |
M1-R PCRpt Message: | | | | |
CC-ID=X7 | | +v-+ | |
EPR Object(Peer Address=R1_A +------------+ +---+R3+-------------------+ )
Next Hop=R4_A) | | +--+ | |
| | | |
+v-+ +--+ | | +--+ +-v+
|R1+------+R5++ +----------------+R6+----+R7|
++-+ +--+ | | +--+ +-++
| | | |
M3 PCInitiate Message | +---+ +---+ |
CC-ID=X2(Symbolic Path Name=Class A) | +v-+ | | +v-+ |
EPR Object(Peer Address=R1_A +----------+R2+-+ +--------+R4+-----------+
Next Hop=R1_A) | |
| |
M3-R PCRpt Message | |
CC-ID=X2(Symbolic Path Name=Class A) <----------------------+ |
EPR Object(Peer Address=R1_A |
Next Hop=R1_A) |
v
M2 PCInitiate Message
CC-ID=X4(Symbolic Path Name=Class A)
EPR Object(Peer Address=R1_A
Next Hop=R2_A)
M2-R PCRpt Message
CC-ID=X4(Symbolic Path Name=Class A)
EPR Object(Peer Address=R1_A
Next Hop=R2_A)
Figure 3: Explicit Route Establish Procedures(From R7 to R1)
Upon the error occurs, the PCC SHOULD send the corresponding
error(Error-type=TBD, Error-value=03) information that defined in
Section 8. When the peer info that associated with the Symbolic Path
Name is not the same as the peer info that indicated in EPR object in
PCC, an error (Error-type=TBD, Error-value=04) should be reported via
the PCRpt message.
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6.3. BGP Prefix Advertisement Procedures
The detail procedures for BGP prefix advertisement is shown below,
using PCInitiate and PCRpt message pair.
The PCInitiate message should be sent to PCC that acts as BGP peer
router only. In the example, it should be sent to R1(M1) and R7(M2)
respectively.
When PCC receives the PPA and the CCI object (with the R bit set to 0
in SRP object) in PCInitiate message, the PCC should send the
prefixes indicated in this object to the appointed BGP peer.
When PCC sends successfully the prefixes to the appointed BGP peer,
it should report the result via the PCRpt messages, with PPA object
included, and the corresponding SRP and CCI object.
When PCC receives the PPA and the CCI object with the R bit set to 1
in SRP object in PCInitiate message, the PCC should withdraw the
prefixes advertisement to the peer that indicated by this object.
When PCC withdraws successfully the prefixes that indicated by this
object, it should report the result via the PCRpt message, with the
PPA object included, and the corresponding SRP and CCI object.
The IPv4 prefix MUST only be advertised via the IPv4 BGP session and
the IPv6 prefix MUST only be advertised via the IPv6 BGP session. If
mismatch occur, an error(Error-type=TBD, Error-value=05) should be
reported.
When the peer info that associated with the Symbolic Path Name is not
the same as the peer info that indicated in PPA object in PCC, an
error (Error-type=TBD, Error-value=06) should be reported via the
PCRpt message.
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M2 PCInitiate Message:
CC-ID=X7(Symbolic Path Name=Class A)
PPA Object(Peer IP=R1_A, Prefix=7_A)
<-----+
M2-R PCRpt Message: |
CC-ID=X7 |
PPA Object(Peer IP=R1_A, Prefix=7_A) |
|
|
|
+------------------+ |
M1 PCInitiate Message: +----------+ PCE +-----------+ |
CC-ID=X1(Symbolic Path Name=Class A) | +------------------+ | |
PPA Object(Peer IP=R7_A, Prefix=1_A) | | |
| | |
<----------+ +---+
M1-R PCRpt Message: | |
CC-ID=X1 | +--+ |
PPA Object(Peer IP=R7_A,Prefix=1_A) +------------------+R3+-------------------+ )
| +--+ |
| |
+v-+ +--+ +--+ +-v+
|R1+----------+R5+----------+R6+---------+R7|
++-+ +--+ +--+ +-++
| |
| |
| +--+ +--+ |
+------------+R2+----------+R4+-----------+
Figure 4: BGP Prefix Advertisement Procedures
7. New PCEP Objects
One new CCI Object and three new PCEP objects are defined in this
draft. All new PCEP objects are as per [RFC5440]
7.1. CCI Object
The Central Control Instructions (CCI) Object is used by the PCE to
specify the forwarding instructions is defined in
[I-D.ietf-pce-pcep-extension-for-pce-controller]. This document
defines another object-type for Native-IP.
CCI Object-Type is TBD for Native-IP as 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CC-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Flags |
+---------------------------------------------------------------+
| |
// Optional TLV //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: CCI Object for Native IP
Figure 1
The field CC-ID is as described in
[I-D.ietf-pce-pcep-extension-for-pce-controller]. Following fields
are defined for CCI Object-Type TBD
Reserved: is set to zero while sending, ignored on receipt.
Flags: is used to carry any additional information pertaining to the
CCI. Currently no flag bits are defined.
The Symbolic Path Name TLV [RFC8231] MUST be included in the CCI
Object-Type TBD to identify the end to end TE path in Native IP
environment and MUST be unique.
7.2. BGP Peer Info Object
The BGP Peer Info object is used to specify the information about the
peer that the PCC should establish the BGP relationship with. This
object should only be included and sent to the head and end router of
the E2E path in case there is no Route Reflection (RR) involved. If
the RR is used between the head and end routers, then such
information should be sent to head router, RR and end router
respectively.
By default, there MUST be no prefix be distributed via such BGP
session that established by this object.
By default, the Local/Peer IP address SHOULD be dedicated to the
usage of native IP TE solution, and SHOULD NOT be used by other BGP
sessions that established by manual or non PCE initiated
configuration.
BGP Peer Info Object-Class is TBD
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BGP Peer Info Object-Type is 1 for IPv4 and 2 for IPv6
The format of the BGP Peer Info object body for IPv4(Object-Type=1)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer AS Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ETTL | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local IP Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer IP Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Additional TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: BGP Peer Info Object Body Format for IPv4
The format of the BGP Peer Info object body for IPv6(Object-Type=2)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer AS Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ETTL | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| Local IP Address (16 bytes) |
+ +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| Peer IP Address (16 bytes) |
+ +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Additional TLVs |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: BGP Peer Info Object Body Format for IPv6
Peer AS Number: 4 Bytes, to indicate the AS number of Remote Peer.
ETTL: 1 Bytes, to indicate the multi hop count for EBGP session. It
should be 0 and ignored when Local AS and Peer AS is same.
Reserved: is set to zero while sending, ignored on receipt..
Local IP Address(4/16 Bytes): IP address of the local router, used to
peer with other end router. When Object-Type is 1, length is 4
bytes; when Object-Type is 2, length is 16 bytes.
Peer IP Address(4/16 Bytes): IP address of the peer router, used to
peer with the local router. When Object-Type is 1, length is 4
bytes; when Object-Type is 2, length is 16 bytes;
Additional TLVs: TLVs that associated with this object, can be used
to convey other necessary information for dynamic BGP session
establishment. Its definition is out of the current document.
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7.3. Explicit Peer Route Object
The Explicit Peer Route object is defined to specify the explicit
peer route to the corresponding peer address on each device that is
on the E2E assurance path. This Object should be sent to all the
devices that locates on the E2E assurance path that calculated by
PCE.
The path established by this object should have higher priority than
other path calculated by dynamic IGP protocol, but should be lower
priority that the static route configured by manual or NETCONF
channel.
Explicit Peer Route Object-Class is TBD.
Explicit Peer Route Object-Type is 1 for IPv4 and 2 for IPv6
The format of Explicit Peer Route object body for IPv4(Object-Type=1)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Priority | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 Peer Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Hop Address to the IPv4 Peer Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: Explicit Peer Route Object Body Format for IPv4
The format of Explicit Peer Route object body for IPv6(Object-Type=2)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Priority | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| IPv6 Peer Address |
+ +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| Next Hop Address to the IPv6 Peer Address |
+ +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 9: Explicit Peer Route Object Body Format for IPv6
Route Priority: 2 Bytes, The priority of this explicit route. The
higher priority should be preferred by the device.
Reserved.: is set to zero while sending, ignored on receipt.
Peer Address: To indicate the peer address.
Next Hop Address to the Peer: To indicate the next hop address to the
corresponding peer.
7.4. Peer Prefix Association Object
The Peer Prefix Association object is defined to specify the IP
prefixes that should be advertised to the corresponding peer. This
object should only be included and sent to the head/end router of the
end2end path.
The prefixes information included in this object MUST only be
advertised to the indicated peer, MUST NOT be advertised to other BGP
peers.
Peer Prefix Association Object-Class is TBD
Peer Prefix Association Object-Type is 1 for IPv4 and 2 for IPv6
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The format of the Peer Prefix Association object body 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer IPv4 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// IPv4 Prefix subobjects //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 10: Peer Prefix Association Object Body Format for IPv4
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Peer IPv6 Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// IPv6 Prefix subobjects //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 11: Peer Prefix Association Object Body Format for IPv6
Peer IPv4 Address: 4 Bytes. Identifies the peer IPv4 address that
the associated prefixes will be sent to.
IPv4 Prefix subojects: List of IPv4 Prefix subobjects that defined in
[RFC3209], identify the prefixes that will be sent to the peer that
identified by Peer IPv4 Address List.
Peer IPv6 Address: 16 Bytes. Identifies the peer IPv6 address that
the associated prefixes will be sent to.
IPv6 Prefix subojects: List of IPv6 Prefix subobjects that defined in
[RFC3209], identify the prefixes that will be sent to the peer that
identified by Peer IPv6 Address List.
8. New Error-Types and Error-Values Defined
A PCEP-ERROR object is used to report a PCEP error and is
characterized by an Error-Type that specifies that type of error and
an Error-value that provides additional information about the error.
An additional Error-Type and several Error-values are defined to
represent some the errors related to the newly defined objects, which
are related to Native IP TE procedures.
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+============+===============+==============================+
| Error-Type | Meaning | Error-value |
+============+===============+==============================+
| TBD | Native IP | |
| | TE failure | |
+------------+---------------+------------------------------+
| | | 0: Unassigned |
+------------+---------------+------------------------------+
| | | 1: Peer AS not match |
+------------+---------------+------------------------------+
| | | 2: Peer IP can't be reached |
+------------+---------------+------------------------------+
| | | 3: Explicit Peer Route Error |
+------------+---------------+------------------------------+
| | | 4: EPR/BPI Peer Info mismatch|
+------------+---------------+------------------------------+
| | | 5: BPI/PPA Object AF mismatch|
+------------+---------------+------------------------------+
| | | 6: PPA/BPI Peer Info mismatch|
+------------+---------------+------------------------------+
| | | 7: |
+------------+---------------+------------------------------+
| | | 8: |
+------------+---------------+------------------------------+
| | | 8: |
+------------+---------------+------------------------------+
| | | 9: |
+------------+---------------+------------------------------+
Figure 12: Newly defined Error-Type and Error-Value
9. Management Consideration
The information transferred in this draft is mainly used for the
light weight BGP session setup, explicit route deployment and the
prefix distribution. The planning, allocation and distribution of
the peer addresses within IGP should be accomplished in advanced and
they are out of the scope of this draft.
[RFC8232] describes the state synchronization procedure between
stateful PCE and PCC. The communication of PCE and PCC described in
this draft should also follow this procedures, treat the three newly
defined objects that associated with the same symbolic path name as
the attribute of the same path in the LSP-DB.
When PCE detects one or some of the PCCs are out of control, it
should recompute and redeploy the traffic engineering path for native
IP on the active PCCs. When PCC detects that it is out of control of
the PCE, it should clear the information that initiated by the PCE.
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The PCE should assures the avoidance of possible transient loop in
such node failure when it deploy the explicit peer route on the PCCs.
10. Security Considerations
Service provider should consider the protection of PCE and their
communication with the underlay devices, which is described in
document [RFC5440] and [RFC8253]
11. IANA Considerations
11.1. PCEP Object Types
IANA is requested to allocate new registry for the PCEP Object Type:
Object-Class Value Name Reference
TBD CCI Object This document
Object-Type
TBD: Native IP
TBD BGP Peer Info This document
Object-Type
1: IPv4 address
2: IPv6 address
TBD Explicit Peer Route This document
Object-Type
1: IPv4 address
2: IPv6 address
TBD Peer Prefix Association This document
Object-Type
1: IPv4 address
2: IPv6 address
12. Contributor
Dhruv Dhody has contributed the contents of this draft.
13. Acknowledgement
Thanks Mike Koldychev, Siva Sivabalan, Adam Simpson for his valuable
suggestions and comments.
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14. Normative References
[I-D.ietf-pce-pcep-extension-for-pce-controller]
Li, Z., Peng, S., Negi, M., Zhao, Q., and C. Zhou, "PCEP
Procedures and Protocol Extensions for Using PCE as a
Central Controller (PCECC) of LSPs", draft-ietf-pce-pcep-
extension-for-pce-controller-07 (work in progress),
September 2020.
[I-D.ietf-teas-pce-native-ip]
Wang, A., Khasanov, B., Zhao, Q., and H. Chen, "PCE in
Native IP Network", draft-ietf-teas-pce-native-ip-11 (work
in progress), August 2020.
[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>.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
<https://www.rfc-editor.org/info/rfc3209>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009,
<https://www.rfc-editor.org/info/rfc5440>.
[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>.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017,
<https://www.rfc-editor.org/info/rfc8231>.
[RFC8232] Crabbe, E., Minei, I., Medved, J., Varga, R., Zhang, X.,
and D. Dhody, "Optimizations of Label Switched Path State
Synchronization Procedures for a Stateful PCE", RFC 8232,
DOI 10.17487/RFC8232, September 2017,
<https://www.rfc-editor.org/info/rfc8232>.
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[RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody,
"PCEPS: Usage of TLS to Provide a Secure Transport for the
Path Computation Element Communication Protocol (PCEP)",
RFC 8253, DOI 10.17487/RFC8253, October 2017,
<https://www.rfc-editor.org/info/rfc8253>.
[RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for PCE-Initiated LSP Setup in a Stateful PCE
Model", RFC 8281, DOI 10.17487/RFC8281, December 2017,
<https://www.rfc-editor.org/info/rfc8281>.
[RFC8283] Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An
Architecture for Use of PCE and the PCE Communication
Protocol (PCEP) in a Network with Central Control",
RFC 8283, DOI 10.17487/RFC8283, December 2017,
<https://www.rfc-editor.org/info/rfc8283>.
[RFC8408] Sivabalan, S., Tantsura, J., Minei, I., Varga, R., and J.
Hardwick, "Conveying Path Setup Type in PCE Communication
Protocol (PCEP) Messages", RFC 8408, DOI 10.17487/RFC8408,
July 2018, <https://www.rfc-editor.org/info/rfc8408>.
[RFC8735] Wang, A., Huang, X., Kou, C., Li, Z., and P. Mi,
"Scenarios and Simulation Results of PCE in a Native IP
Network", RFC 8735, DOI 10.17487/RFC8735, February 2020,
<https://www.rfc-editor.org/info/rfc8735>.
Authors' Addresses
Aijun Wang
China Telecom
Beiqijia Town, Changping District
Beijing, Beijing 102209
China
Email: wangaj3@chinatelecom.cn
Boris Khasanov
Huawei Technologies,Co.,Ltd
Moskovskiy Prospekt 97A
St.Petersburg 196084
Russia
Email: bhassanov@yahoo.com
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Sheng Fang
Huawei Technologies,Co.,Ltd
Huawei Bld., No.156 Beiqing Rd.
Beijing
China
Email: fsheng@huawei.com
Ren Tan
Huawei Technologies,Co.,Ltd
Huawei Bld., No.156 Beiqing Rd.
Beijing
China
Email: tanren@huawei.com
Chun Zhu
ZTE Corporation
50 Software Avenue, Yuhua District
Nanjing, Jiangsu 210012
China
Email: zhu.chun1@zte.com.cn
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