< draft-ietf-pce-binding-label-sid-12.txt   draft-ietf-pce-binding-label-sid-13.txt >
PCE Working Group S. Sivabalan PCE Working Group S. Sivabalan
Internet-Draft Ciena Corporation Internet-Draft Ciena Corporation
Intended status: Standards Track C. Filsfils Intended status: Standards Track C. Filsfils
Expires: 28 July 2022 Cisco Systems, Inc. Expires: 14 August 2022 Cisco Systems, Inc.
J. Tantsura J. Tantsura
Microsoft Corporation Microsoft Corporation
S. Previdi S. Previdi
C. Li, Ed. C. Li, Ed.
Huawei Technologies Huawei Technologies
24 January 2022 10 February 2022
Carrying Binding Label/Segment Identifier in PCE-based Networks. Carrying Binding Label/Segment Identifier (SID) in PCE-based Networks.
draft-ietf-pce-binding-label-sid-12 draft-ietf-pce-binding-label-sid-13
Abstract Abstract
In order to provide greater scalability, network confidentiality, and In order to provide greater scalability, network confidentiality, and
service independence, Segment Routing (SR) utilizes a Binding Segment service independence, Segment Routing (SR) utilizes a Binding Segment
Identifier (BSID). It is possible to associate a BSID to an RSVP-TE- Identifier (SID) (called BSID) as described in RFC 8402. It is
signaled Traffic Engineering Label Switched Path or an SR Traffic possible to associate a BSID to an RSVP-TE-signaled Traffic
Engineering path. The BSID can be used by an upstream node for Engineering Label Switched Path or an SR Traffic Engineering path.
steering traffic into the appropriate TE path to enforce SR policies. The BSID can be used by an upstream node for steering traffic into
This document specifies the concept of binding value, which can be the appropriate TE path to enforce SR policies. This document
either an MPLS label or Segment Identifier. It further specifies an specifies the concept of binding value, which can be either an MPLS
extension to Path Computation Element (PCE) communication label or Segment Identifier. It further specifies an extension to
Protocol(PCEP) for reporting the binding value by a Path Computation Path Computation Element (PCE) communication Protocol(PCEP) for
Client (PCC) to the PCE to support PCE-based Traffic Engineering reporting the binding value by a Path Computation Client (PCC) to the
policies. PCE to support PCE-based Traffic Engineering policies.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 28 July 2022. This Internet-Draft will expire on 14 August 2022.
Copyright Notice Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/ Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document. license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights Please review these documents carefully, as they describe your rights
skipping to change at page 2, line 28 skipping to change at page 2, line 28
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Motivation and Example . . . . . . . . . . . . . . . . . 4 1.1. Motivation and Example . . . . . . . . . . . . . . . . . 4
1.2. Summary of the Extension . . . . . . . . . . . . . . . . 5 1.2. Summary of the Extension . . . . . . . . . . . . . . . . 5
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 5
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. Path Binding TLV . . . . . . . . . . . . . . . . . . . . . . 6 4. Path Binding TLV . . . . . . . . . . . . . . . . . . . . . . 6
4.1. SRv6 Endpoint Behavior and SID Structure . . . . . . . . 8 4.1. SRv6 Endpoint Behavior and SID Structure . . . . . . . . 8
5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6. Binding SID in SR-ERO . . . . . . . . . . . . . . . . . . . . 11 6. Binding SID in SR-ERO . . . . . . . . . . . . . . . . . . . . 12
7. Binding SID in SRv6-ERO . . . . . . . . . . . . . . . . . . . 11 7. Binding SID in SRv6-ERO . . . . . . . . . . . . . . . . . . . 12
8. PCE Allocation of Binding label/SID . . . . . . . . . . . . . 11 8. PCE Allocation of Binding label/SID . . . . . . . . . . . . . 12
9. Implementation Status . . . . . . . . . . . . . . . . . . . . 13 9. Implementation Status . . . . . . . . . . . . . . . . . . . . 14
9.1. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 13 9.1. Huawei . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.2. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . . 14 9.2. Cisco . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10. Security Considerations . . . . . . . . . . . . . . . . . . . 14 10. Security Considerations . . . . . . . . . . . . . . . . . . . 16
11. Manageability Considerations . . . . . . . . . . . . . . . . 15 11. Manageability Considerations . . . . . . . . . . . . . . . . 16
11.1. Control of Function and Policy . . . . . . . . . . . . . 15 11.1. Control of Function and Policy . . . . . . . . . . . . . 17
11.2. Information and Data Models . . . . . . . . . . . . . . 15 11.2. Information and Data Models . . . . . . . . . . . . . . 17
11.3. Liveness Detection and Monitoring . . . . . . . . . . . 15 11.3. Liveness Detection and Monitoring . . . . . . . . . . . 17
11.4. Verify Correct Operations . . . . . . . . . . . . . . . 15 11.4. Verify Correct Operations . . . . . . . . . . . . . . . 17
11.5. Requirements On Other Protocols . . . . . . . . . . . . 15 11.5. Requirements On Other Protocols . . . . . . . . . . . . 17
11.6. Impact On Network Operations . . . . . . . . . . . . . . 15 11.6. Impact On Network Operations . . . . . . . . . . . . . . 17
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
12.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 16 12.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 17
12.1.1. TE-PATH-BINDING TLV . . . . . . . . . . . . . . . . 16 12.1.1. TE-PATH-BINDING TLV . . . . . . . . . . . . . . . . 18
12.2. LSP Object . . . . . . . . . . . . . . . . . . . . . . . 17 12.2. LSP Object . . . . . . . . . . . . . . . . . . . . . . . 19
12.3. PCEP Error Type and Value . . . . . . . . . . . . . . . 17 12.3. PCEP Error Type and Value . . . . . . . . . . . . . . . 19
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 20
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 20
14.1. Normative References . . . . . . . . . . . . . . . . . . 18 14.1. Normative References . . . . . . . . . . . . . . . . . . 20
14.2. Informative References . . . . . . . . . . . . . . . . . 20 14.2. Informative References . . . . . . . . . . . . . . . . . 22
Appendix A. Contributor Addresses . . . . . . . . . . . . . . . 21 Appendix A. Contributor Addresses . . . . . . . . . . . . . . . 24
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24
1. Introduction 1. Introduction
A Path Computation Element (PCE) can compute Traffic Engineering A Path Computation Element (PCE) can compute Traffic Engineering
paths (TE paths) through a network where those paths are subject to paths (TE paths) through a network where those paths are subject to
various constraints. Currently, TE paths are set up using either the various constraints. Currently, TE paths are set up using either the
RSVP-TE signaling protocol or Segment Routing (SR). We refer to such RSVP-TE signaling protocol or Segment Routing (SR). We refer to such
paths as RSVP-TE paths and SR-TE paths respectively in this document. paths as RSVP-TE paths and SR-TE paths respectively in this document.
As per [RFC8402] SR allows a head-end node to steer a packet flow As per [RFC8402] SR allows a head-end node to steer a packet flow
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document, the term 'binding label/SID' is used to generalize the document, the term 'binding label/SID' is used to generalize the
allocation of binding value for both SR and non-SR paths. allocation of binding value for both SR and non-SR paths.
[RFC5440] describes the PCEP for communication between a Path [RFC5440] describes the PCEP for communication between a Path
Computation Client (PCC) and a PCE or between a pair of PCEs as per Computation Client (PCC) and a PCE or between a pair of PCEs as per
[RFC4655]. [RFC8231] specifies extensions to PCEP that allow a PCC [RFC4655]. [RFC8231] specifies extensions to PCEP that allow a PCC
to delegate its Label Switched Paths (LSPs) to a stateful PCE. A to delegate its Label Switched Paths (LSPs) to a stateful PCE. A
stateful PCE can then update the state of LSPs delegated to it. stateful PCE can then update the state of LSPs delegated to it.
[RFC8281] specifies a mechanism allowing a PCE to dynamically [RFC8281] specifies a mechanism allowing a PCE to dynamically
instantiate an LSP on a PCC by sending the path and characteristics. instantiate an LSP on a PCC by sending the path and characteristics.
This document specifies an extension to PCEP to manage of binding This document specifies an extension to PCEP to manage the binding of
label/SID for both SR and non-SR paths. label/SID that can be applied to SR, RSVP-TE, and other path setup
types.
[RFC8664] provides a mechanism for a PCE (acting as a network [RFC8664] provides a mechanism for a PCE (acting as a network
controller) to instantiate SR-TE paths (candidate paths) for an SR controller) to instantiate SR-TE paths (candidate paths) for an SR
Policy onto a head-end node (acting as a PCC) using PCEP. For more Policy onto a head-end node (acting as a PCC) using PCEP. For more
information on the SR Policy Architecture, see information on the SR Policy Architecture, see
[I-D.ietf-spring-segment-routing-policy]. [I-D.ietf-spring-segment-routing-policy].
1.1. Motivation and Example 1.1. Motivation and Example
A binding label/SID has local significance to the ingress node of the A binding label/SID has local significance to the ingress node of the
corresponding TE path. When a stateful PCE is deployed for setting corresponding TE path. When a stateful PCE is deployed for setting
up TE paths, a binding label/SID reported from the PCC to the up TE paths, a binding label/SID reported from the PCC to the
stateful PCE is useful for the purpose of enforcing end-to-end TE/SR stateful PCE is useful for the purpose of enforcing end-to-end TE/SR
policy. A sample Data Center (DC) use-case is illustrated in policy. A sample Data Center (DC) and IP/MPLS WAN use-case is
Figure 1. In the MPLS DC network, an SR LSP (without traffic illustrated in Figure 1 with a multi-domain PCE. In the IP/MPLS WAN,
engineering) is established using a prefix SID advertised by BGP (see an SR-TE LSP is set up using the PCE. The list of SIDs of the SR-TE
[RFC8669]). In the IP/MPLS WAN, an SR-TE LSP is set up using the LSP is {A, B, C, D}. The gateway node 1 (which is the PCC) allocates
PCE. The list of SIDs of the SR-TE LSP is {A, B, C, D}. The gateway a binding SID X and reports it to the PCE. In the MPLS DC network,
node 1 (which is the PCC) allocates a binding SID X and reports it to an end-to-end SR-TE LSP is established. In order for the access node
the PCE. In order for the access node to steer the traffic over the to steer the traffic towards Node-1 and over the SR-TE path in WAN,
SR-TE LSP, the PCE passes the SID stack {Y, X} where Y is the prefix the PCE passes the SID stack {Y, X} where Y is the node SID of the
SID of the gateway node-1 to the access node. In the absence of the gateway node-1 to the access node and X is the BSID. In the absence
binding SID X, the PCE would pass the SID stack {Y, A, B, C, D} to of the BSID X, the PCE would need to pass the SID stack {Y, A, B, C,
the access node. This example also illustrates the additional D} to the access node. This example also illustrates the additional
benefit of using the binding label/SID to reduce the number of SIDs benefit of using the binding label/SID to reduce the number of SIDs
imposed by the access nodes with a limited forwarding capacity. imposed by the access nodes with a limited forwarding capacity.
SID stack SID stack
{Y, X} +-----+ {Y, X} +--------------+
_ _ _ _ _ _ _ _ _ _ _ _ _ _| PCE | | Multi-domain |
| +-----+ _ _ _ _ _ _ _ _ _ _ _ _ _ _| PCE |
| +--------------+
| ^ | ^
| | Binding | | Binding
| .-----. | SID (X) .-----. | .-----. | SID (X) .-----.
| ( ) | ( ) | ( ) | ( )
V .--( )--. | .--( )--. V .--( )--. | .--( )--.
+------+ ( ) +-------+ ( ) +-------+ +------+ ( ) +-------+ ( ) +-------+
|Access|_( MPLS DC Network )_|Gateway|_( IP/MPLS WAN )_|Gateway| |Access|_( MPLS DC Network )_|Gateway|_( IP/MPLS WAN )_|Gateway|
| Node | ( ==============> ) |Node-1 | ( ================> ) |Node-2 | | Node | ( ==============> ) |Node-1 | ( ================> ) |Node-2 |
+------+ ( SR path ) +-------+ ( SR-TE path ) +-------+ +------+ ( SR-TE path ) +-------+ ( SR-TE path ) +-------+
'--( )--' Prefix '--( )--' '--( )--' Node '--( )--'
( ) SID of ( ) ( ) SID of ( )
'-----' Node-1 '-----' '-----' Node-1 '-----'
is Y SIDs for SR-TE LSP: is Y SIDs for SR-TE LSP:
{A, B, C, D} {A, B, C, D}
Figure 1: A Sample Use-case of Binding SID Figure 1: A Sample Use-case of Binding SID
Using the extension defined in this document, a PCC could report to Using the extension defined in this document, a PCC could report to
the stateful PCE the binding label/SID it allocated via a Path the stateful PCE the binding label/SID it allocated via a Path
Computation LSP State Report (PCRpt) message. It is also possible Computation LSP State Report (PCRpt) message. It is also possible
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value, it reports the binding value to the PCE. Otherwise, the PCC value, it reports the binding value to the PCE. Otherwise, the PCC
sends an error message to the PCE indicating the cause of the sends an error message to the PCE indicating the cause of the
failure. A local policy or configuration at the PCC SHOULD dictate failure. A local policy or configuration at the PCC SHOULD dictate
if the binding label/SID needs to be assigned. if the binding label/SID needs to be assigned.
1.2. Summary of the Extension 1.2. Summary of the Extension
To implement the needed changes to PCEP, in this document, we To implement the needed changes to PCEP, in this document, we
introduce a new OPTIONAL TLV that a PCC can use in order to report introduce a new OPTIONAL TLV that a PCC can use in order to report
the binding label/SID associated with a TE LSP, or a PCE to request a the binding label/SID associated with a TE LSP, or a PCE to request a
PCC to allocate a specific binding label/SID value. This TLV is PCC to allocate any or a specific binding label/SID value. This TLV
intended for TE LSPs established using RSVP-TE, SR, or any other is intended for TE LSPs established using RSVP-TE, SR-TE, or any
future method. Also, in the case of SR-TE LSPs, the TLV can carry a other future method. In the case of SR-TE LSPs, the TLV can carry a
binding label (for SR-TE path with MPLS data-plane) or a binding IPv6 binding label (for SR-TE path with MPLS data-plane) or a binding IPv6
SID (e.g., IPv6 address for SR-TE paths with IPv6 data-plane). SID (e.g., IPv6 address for SR-TE paths with IPv6 data-plane).
Throughout this document, the term "binding value" means either an Throughout this document, the term "binding value" means either an
MPLS label or a SID. MPLS label or a SID.
As another way to use the extension specified in this document, to As another way to use the extension specified in this document, to
support the PCE-based central controller [RFC8283] operation where support the PCE-based central controller [RFC8283] operation where
the PCE would take responsibility for managing some part of the MPLS the PCE would take responsibility for managing some part of the MPLS
label space for each of the routers that it controls, the PCE could label space for each of the routers that it controls, the PCE could
directly make the binding label/SID allocation and inform the PCC. directly make the binding label/SID allocation and inform the PCC.
See Section 8 for details. See Section 8 for details.
In addition to specifying a new TLV, this document specifies how and In addition to specifying a new TLV, this document specifies how and
when a PCC and PCE can use this TLV, how they can can allocate a when a PCC and PCE can use this TLV, how they can allocate a binding
binding label/SID, and associted error handling. label/SID, and associated error handling.
2. Requirements Language 2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Terminology 3. Terminology
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* BT = 2: The binding value is an SRv6 SID with the format of a * BT = 2: The binding value is an SRv6 SID with the format of a
16-octet IPv6 address, representing the binding SID for SRv6. The 16-octet IPv6 address, representing the binding SID for SRv6. The
Length MUST be set to 20. Length MUST be set to 20.
* BT = 3: The binding value is a 24 octet field, defined in * BT = 3: The binding value is a 24 octet field, defined in
Section 4.1, that contains the SRv6 SID as well as its Behavior Section 4.1, that contains the SRv6 SID as well as its Behavior
and Structure. The Length MUST be set to 28. and Structure. The Length MUST be set to 28.
Section 12.1.1 defines the IANA registry used to maintain all these Section 12.1.1 defines the IANA registry used to maintain all these
binding types as well as any future ones. Note that multiple TE- binding types as well as any future ones. Note that multiple TE-
PATH-BINDING TLVs with different Binding Types MAY be present for the PATH-BINDING TLVs with same or different Binding Types MAY be present
same LSP. for the same LSP. A PCEP speaker could allocate multiple TE-PATH-
BINDING TLVs (of the same BT), and use different binding values in
different domains or use-cases based on a local policy.
Flags: 1 octet of flags. The following flag is defined in the new Flags: 1 octet of flags. The following flag is defined in the new
registry "TE-PATH-BINDING TLV Flag field" as described in registry "TE-PATH-BINDING TLV Flag field" as described in
Section 12.1.1: Section 12.1.1:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|R| | |R| |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
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* The unassigned flags MUST be set to 0 while sending and ignored on * The unassigned flags MUST be set to 0 while sending and ignored on
receipt. receipt.
Reserved: MUST be set to 0 while sending and ignored on receipt. Reserved: MUST be set to 0 while sending and ignored on receipt.
Binding Value: A variable-length field, padded with trailing zeros to Binding Value: A variable-length field, padded with trailing zeros to
a 4-octet boundary. When the BT is 0, the 20 bits represent the MPLS a 4-octet boundary. When the BT is 0, the 20 bits represent the MPLS
label. When the BT is 1, the 32 bits represent the MPLS label stack label. When the BT is 1, the 32 bits represent the MPLS label stack
entry as per [RFC3032]. When the BT is 2, the 128 bits represent the entry as per [RFC3032]. When the BT is 2, the 128 bits represent the
SRv6 SID. When the BT is 3, the Binding Value also contains the SRv6 SRv6 SID. When the BT is 3, the Binding Value also contains the SRv6
Endpoint Behavior and SID Structure, defined in Section 4.1. Endpoint Behavior and SID Structure, defined in Section 4.1. In this
document, the TE-PATH-BINDING TLV is considered to be empty if no
Binding Value is present. Note that the length of the TLV would be 4
in such a case.
4.1. SRv6 Endpoint Behavior and SID Structure 4.1. SRv6 Endpoint Behavior and SID Structure
This section specifies the format of the Binding Value in the TE- This section specifies the format of the Binding Value in the TE-
PATH-BINDING TLV when the BT is set to 3 for the SRv6 Binding SIDs PATH-BINDING TLV when the BT is set to 3 for the SRv6 Binding SIDs
[RFC8986]. The format is shown in Figure 4. [RFC8986]. The format is shown in Figure 4.
0 1 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| SRv6 Binding SID (16 octets) | | SRv6 Binding SID (16 octets) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Endpoint Behavior | | Reserved | Endpoint Behavior |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LB Length | LN Length | Fun. Length | Arg. Length | | LB Length | LN Length | Fun. Length | Arg. Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: SRv6 Endpoint Behavior and SID Structure Figure 4: SRv6 Endpoint Behavior and SID Structure
The Binding Value consists of: The Binding Value consists of:
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representing the binding SID for SRv6. representing the binding SID for SRv6.
* Reserved: 2 octets. It MUST be set to 0 on transmit and ignored * Reserved: 2 octets. It MUST be set to 0 on transmit and ignored
on receipt. on receipt.
* Endpoint Behavior: 2 octets. The Endpoint Behavior code point for * Endpoint Behavior: 2 octets. The Endpoint Behavior code point for
this SRv6 SID as per the IANA subregistry called "SRv6 Endpoint this SRv6 SID as per the IANA subregistry called "SRv6 Endpoint
Behaviors", created by [RFC8986]. When the field is set with the Behaviors", created by [RFC8986]. When the field is set with the
value 0, the endpoint behavior is considered unknown. value 0, the endpoint behavior is considered unknown.
* The following fields are used to advertise the length of each * [RFC8986] defines an SRv6 SID as consisting of LOC:FUNCT:ARG,
individual part of the SRv6 SID as defined in [RFC8986]: where a locator (LOC) is encoded in the L most significant bits of
the SID, followed by F bits of function (FUNCT) and A bits of
arguments (ARG). A locator may be represented as B:N where B is
the SRv6 SID locator block (IPv6 prefix allocated for SRv6 SIDs by
the operator) and N is the identifier of the parent node
instantiating the SID called locator node. The following fields
are used to advertise the length of each individual part of the
SRv6 SID as defined in :
- LB Length: 1 octet. SRv6 SID Locator Block length in bits. - LB Length: 1 octet. SRv6 SID Locator Block length in bits.
- LN Length: 1 octet. SRv6 SID Locator Node length in bits. - LN Length: 1 octet. SRv6 SID Locator Node length in bits.
- Function Length: 1 octet. SRv6 SID Function length in bits. - Function Length: 1 octet. SRv6 SID Function length in bits.
- Argument Length: 1 octet. SRv6 SID Arguments length in bits. - Argument Length: 1 octet. SRv6 SID Arguments length in bits.
The total of the locator block, locator node, function, and argument
lengths MUST be lower or equal to 128 bits. If this condition is not
met, the corresponding TE-PATH-BINDING TLV MUST be considered as an
error. Also, if the Endpoint Behavior is found to be unknown or
inconsistent, it is considered an error. A PCErr message with Error-
Type = 10 ("Reception of an invalid object") and Error-Value = 37
("Invalid SRv6 SID Structure") MUST be sent.
The SRv6 SID Structure could be used by the PCE for ease of
operations and monitoring. For example, this information could be
used for validation of SRv6 SIDs being instantiated in the network
and checked for conformance to the SRv6 SID allocation scheme chosen
by the operator as described in Section 3.2 of [RFC8986]. In the
future, PCE could also be used for verification and the automation
for securing the SRv6 domain by provisioning filtering rules at SR
domain boundaries as described in Section 5 of [RFC8754]. The
details of these potential applications are outside the scope of this
document.
5. Operation 5. Operation
The binding value is allocated by the PCC and reported to a PCE via a The binding value is usually allocated by the PCC and reported to a
PCRpt message. If a PCE does not recognize the TE-PATH-BINDING TLV, PCE via a PCRpt message (see Section 8 where PCE does the
it would ignore the TLV in accordance with [RFC5440]. If a PCE allocation). If a PCE does not recognize the TE-PATH-BINDING TLV, it
would ignore the TLV in accordance with [RFC5440]. If a PCE
recognizes the TLV but does not support the TLV, it MUST send a PCErr recognizes the TLV but does not support the TLV, it MUST send a PCErr
with Error-Type = 2 (Capability not supported). with Error-Type = 2 (Capability not supported).
Multiple TE-PATH-BINDING TLVs are allowed to be present in the same Multiple TE-PATH-BINDING TLVs are allowed to be present in the same
LSP object. This signifies the presence of multiple binding SIDs for LSP object. This signifies the presence of multiple binding SIDs for
the given LSP. In the case of multiple TE-PATH-BINDING TLVs, the the given LSP. In the case of multiple TE-PATH-BINDING TLVs, the
existing instances of TE-PATH-BINDING TLVs MAY be included in the LSP existing instances of TE-PATH-BINDING TLVs MAY be included in the LSP
object. In case of an error condition, the whole message is rejected object. In case of an error condition, the whole message is rejected
and the resulting PCErr message MAY include the offending TE-PATH- and the resulting PCErr message MAY include the offending TE-PATH-
BINDING TLV in the PCEP-ERROR object. BINDING TLV in the PCEP-ERROR object.
skipping to change at page 9, line 44 skipping to change at page 10, line 41
sender MAY choose to set the BT to 2, in which case the receiving sender MAY choose to set the BT to 2, in which case the receiving
implementation chooses how to interpret the SRv6 Endpoint Behavior implementation chooses how to interpret the SRv6 Endpoint Behavior
and SID Structure according to local policy. and SID Structure according to local policy.
If a PCC wishes to withdraw a previously reported binding value, it If a PCC wishes to withdraw a previously reported binding value, it
MUST send a PCRpt message with the specific TE-PATH-BINDING TLV with MUST send a PCRpt message with the specific TE-PATH-BINDING TLV with
R flag set to 1. If a PCC wishes to modify a previously reported R flag set to 1. If a PCC wishes to modify a previously reported
binding, it MUST withdraw the former binding value (with R flag set binding, it MUST withdraw the former binding value (with R flag set
in the former TE-PATH-BINDING TLV) and include a new TE-PATH-BINDING in the former TE-PATH-BINDING TLV) and include a new TE-PATH-BINDING
TLV containing the new binding value. Note that other instances of TLV containing the new binding value. Note that other instances of
TE-PATH-BINDING TLVs that are unchanged MAY also be included. TE-PATH-BINDING TLVs that are unchanged MAY also be included. If the
unchanged instances are not included, they will remain associated
with the LSP.
If a PCE requires a PCC to allocate a (or several) specific binding If a PCE requires a PCC to allocate a (or several) specific binding
value(s), it may do so by sending a PCUpd or PCInitiate message value(s), it may do so by sending a PCUpd or PCInitiate message
containing a TE-PATH-BINDING TLV(s). If the value(s) can be containing a TE-PATH-BINDING TLV(s). If the value(s) can be
successfully allocated, the PCC reports the binding value(s) to the successfully allocated, the PCC reports the binding value(s) to the
PCE. If the PCC considers the binding value specified by the PCE PCE. If the PCC considers the binding value specified by the PCE
invalid, it MUST send a PCErr message with Error-Type = TBD2 invalid, it MUST send a PCErr message with Error-Type = TBD2
("Binding label/SID failure") and Error Value = TBD3 ("Invalid SID"). ("Binding label/SID failure") and Error Value = TBD3 ("Invalid SID").
If the binding value is valid, but the PCC is unable to allocate the If the binding value is valid, but the PCC is unable to allocate the
binding value, it MUST send a PCErr message with Error-Type = TBD2 binding value, it MUST send a PCErr message with Error-Type = TBD2
("Binding label/SID failure") and Error Value = TBD4 ("Unable to ("Binding label/SID failure") and Error Value = TBD4 ("Unable to
allocate the specified binding value"). Note that, in case of an allocate the specified binding value"). Note that, in case of an
error, the PCC rejects the PCUpd or PCInitiate message in its error, the PCC rejects the PCUpd or PCInitiate message in its
entirety and can include the offending TE-PATH-BINDING TLV in the entirety and can include the offending TE-PATH-BINDING TLV in the
PCEP-ERROR object. PCEP-ERROR object.
If a PCE wishes to request the withdrawal of a previously reported If a PCE wishes to request the withdrawal of a previously reported
binding value, it MUST send a PCUpd message with the specific TE- binding value, it MUST send a PCUpd message with the specific TE-
PATH-BINDING TLV with R flag set to 1. If a PCE wishes to modify a PATH-BINDING TLV with R flag set to 1. If a PCE wishes to modify a
previously requested binding value, it MUST request the withdrawal of previously requested binding value, it MUST request the withdrawal of
the former binding value (with R flag set in the former TE-PATH- the former binding value (with R flag set in the former TE-PATH-
BINDING TLV) and include a new TE-PATH-BINDING TLV containing the new BINDING TLV) and include a new TE-PATH-BINDING TLV containing the new
binding value. binding value. If a PCC receives a PCUpd message with TE-PATH-
BINDING TLV where the R flag is set to 1, but either the binding
value is missing (empty TE-PATH-BINDING TLV) or the binding value is
incorrect, it MUST send a PCErr message with Error-Type = TBD2
("Binding label/SID failure") and Error Value = TBD6 ("Unable to
remove the binding value").
In some cases, a stateful PCE may want to request that the PCC In some cases, a stateful PCE may want to request that the PCC
allocate a binding value of the PCC's own choosing. It instructs the allocate a binding value of the PCC's own choosing. It instructs the
PCC by sending a PCUpd message containing an empty TE-PATH-BINDING PCC by sending a PCUpd message containing an empty TE-PATH-BINDING
TLV, i.e., no binding value is specified (bringing the Length field TLV, i.e., no binding value is specified (bringing the Length field
of the TLV to 4). A PCE can also request a PCC to allocate a binding of the TLV to 4). A PCE can also request a PCC to allocate a binding
value at the time of initiation by sending a PCInitiate message with value at the time of initiation by sending a PCInitiate message with
an empty TE-PATH-BINDING TLV. Only one such instance of empty TE- an empty TE-PATH-BINDING TLV. Only one such instance of empty TE-
PATH-BINDING TLV SHOULD be included in the LSP object and others PATH-BINDING TLV, per BT, SHOULD be included in the LSP object and
ignored on receipt. If the PCC is unable to allocate a new binding others ignored on receipt. If the PCC is unable to allocate a new
value as per the specified BT, it MUST send a PCErr message with binding value as per the specified BT, it MUST send a PCErr message
Error-Type = TBD2 ("Binding label/SID failure") and Error-Value = with Error-Type = TBD2 ("Binding label/SID failure") and Error-Value
TBD5 ("Unable to allocate a new binding label/SID"). = TBD5 ("Unable to allocate a new binding label/SID").
As previously noted, if a message contains an invalid TE-PATH-BINDING As previously noted, if a message contains an invalid TE-PATH-BINDING
TLV that leads to an error condition, the whole message is rejected TLV that leads to an error condition, the whole message is rejected
including any other valid instances of TE-PATH-BINDING TLVs, if any. including any other valid instances of TE-PATH-BINDING TLVs, if any.
The resulting error message MAY include the offending TE-PATH-BINDING The resulting error message MAY include the offending TE-PATH-BINDING
TLV in the PCEP-ERROR object. TLV in the PCEP-ERROR object.
If a PCC receives a TE-PATH-BINDING TLV in any message other than If a PCC receives a TE-PATH-BINDING TLV in any message other than
PCUpd or PCInitiate, it MUST close the corresponding PCEP session PCUpd or PCInitiate, it MUST close the corresponding PCEP session
with the reason "Reception of a malformed PCEP message" (according to with the reason "Reception of a malformed PCEP message" (according to
skipping to change at page 11, line 12 skipping to change at page 12, line 12
the PCE MUST close the corresponding PCEP session with the reason the PCE MUST close the corresponding PCEP session with the reason
"Reception of a malformed PCEP message" (according to [RFC5440]). "Reception of a malformed PCEP message" (according to [RFC5440]).
If a TE-PATH-BINDING TLV is absent in the PCRpt message and no If a TE-PATH-BINDING TLV is absent in the PCRpt message and no
binding values were reported before, the PCE MUST assume that the binding values were reported before, the PCE MUST assume that the
corresponding LSP does not have any binding. Similarly, if TE-PATH- corresponding LSP does not have any binding. Similarly, if TE-PATH-
BINDING TLV is absent in the PCUpd message and no binding values were BINDING TLV is absent in the PCUpd message and no binding values were
reported before, the PCC's local policy dictates how the binding reported before, the PCC's local policy dictates how the binding
allocations are made for a given LSP. allocations are made for a given LSP.
Note that some binding types have similar information but different
binding value formats. For example, BT=(2 or 3) is used for the SRv6
SID and BT=(0 or 1) is used for the MPLS Label. In case a PCEP
speaker receives multiple TE-PATH-BINDING TLVs with the same SRv6 SID
or MPLS Label but different BT values, it MUST send a PCErr message
with Error-Type = TBD2 ("Binding label/SID failure") and Error-Value
= TBD7 ("Inconsistent binding types").
6. Binding SID in SR-ERO 6. Binding SID in SR-ERO
In PCEP messages, LSP route information is carried in the Explicit In PCEP messages, LSP route information is carried in the Explicit
Route Object (ERO), which consists of a sequence of subobjects. Route Object (ERO), which consists of a sequence of subobjects.
[RFC8664] defines the "SR-ERO subobject" capable of carrying a SID as [RFC8664] defines the "SR-ERO subobject" capable of carrying a SID as
well as the identity of the node/adjacency (NAI) represented by the well as the identity of the node/adjacency (NAI) represented by the
SID. The NAI Type (NT) field indicates the type and format of the SID. The NAI Type (NT) field indicates the type and format of the
NAI contained in the SR-ERO. In case of binding SID, the NAI MUST NAI contained in the SR-ERO. In case of binding SID, the NAI MUST
NOT be included and NT MUST be set to zero. [RFC8664] Section 5.2.1 NOT be included and NT MUST be set to zero. [RFC8664] Section 5.2.1
specifies bit settings and error handling in the case when NT=0. specifies bit settings and error handling in the case when NT=0.
skipping to change at page 11, line 46 skipping to change at page 13, line 5
own accord in the case where the PCE also controls the label space of own accord in the case where the PCE also controls the label space of
the PCC and can make the label allocation on its own as described in the PCC and can make the label allocation on its own as described in
[RFC8283]. Note that the act of requesting a specific binding value [RFC8283]. Note that the act of requesting a specific binding value
(Section 5) is different from the act of allocating a binding label/ (Section 5) is different from the act of allocating a binding label/
SID as described in this section. SID as described in this section.
[RFC8283] introduces the architecture for PCE as a central controller [RFC8283] introduces the architecture for PCE as a central controller
as an extension of the architecture described in [RFC4655] and as an extension of the architecture described in [RFC4655] and
assumes the continued use of PCEP as the protocol used between PCE assumes the continued use of PCEP as the protocol used between PCE
and PCC. [RFC9050] specifies the procedures and PCEP extensions for and PCC. [RFC9050] specifies the procedures and PCEP extensions for
using the PCE as the central controller. using the PCE as the central controller. It assumes that the
exclusive label range to be used by a PCE is known and set on both
PCEP peers. A future extension could add the capability to advertise
this range via a possible PCEP extension as well (see
[I-D.li-pce-controlled-id-space]).
When PCECC operations are supported as per [RFC9050], the binding When PCECC operations are supported as per [RFC9050], the binding
label/SID MAY also be allocated by the PCE itself. Both peers need label/SID MAY also be allocated by the PCE itself. Both peers need
to exchange the PCECC capability as described in [RFC9050] before the to exchange the PCECC capability as described in [RFC9050] before the
PCE can allocate the binding label/SID on its own. PCE can allocate the binding label/SID on its own.
A new P flag in the LSP object [RFC8231] is introduced to indicate A new P flag in the LSP object [RFC8231] is introduced to indicate
that the allocation needs to be made by the PCE: that the allocation needs to be made by the PCE. Note that the P
flag could be used for other types of allocations (such as path
segments [I-D.ietf-pce-sr-path-segment]) in future.
* P (PCE-allocated binding label/SID): If the bit is set to 1, it * P (PCE-allocation): If the bit is set to 1, it indicates that the
indicates that the PCC requests PCE to make allocations for this PCC requests PCE to make allocations for this LSP. The TE-PATH-
LSP. The TE-PATH-BINDING TLV in the LSP object identifies that BINDING TLV in the LSP object identifies that the allocation is
the allocation is for a binding label/SID. A PCC MUST set this for a binding label/SID. A PCC MUST set this bit to 1 and include
bit to 1 and include a TE-PATH-BINDING TLV in the LSP object if it a TE-PATH-BINDING TLV in the LSP object if it wishes to request
wishes to request for allocation of binding label/SID by the PCE for allocation of binding label/SID by the PCE in the PCEP
in the PCEP message. A PCE MUST also set this bit to 1 and message. A PCE MUST also set this bit to 1 and include a TE-PATH-
include a TE-PATH-BINDING TLV to indicate that the binding label/ BINDING TLV to indicate that the binding label/SID is allocated by
SID is allocated by PCE and encoded in the PCEP message towards PCE and encoded in the PCEP message towards the PCC. Further, if
the PCC. Further, a PCE MUST set this bit to 0 and include a TE- the binding label/SID is allocated by the PCC, the PCE MUST set
PATH-BINDING TLV in the LSP object if it wishes to indicate that this bit to 0 and follow the procedure described in Section 5.
the binding label/SID should be allocated by the PCC as described
in Section 5.
Note that - Note that -
* A PCE could allocate the binding label/SID of its own accord for a * A PCE could allocate the binding label/SID of its own accord for a
PCE-initiated or delegated LSP, and inform the PCC in the PCE-initiated or delegated LSP, and inform the PCC in the
PCInitiate message or PCUpd message by setting P=1 and including PCInitiate message or PCUpd message by setting P=1 and including
TE-PATH-BINDING TLV in the LSP object. TE-PATH-BINDING TLV in the LSP object.
* To let the PCC allocate the binding label/SID, a PCE MUST set P=0 * To let the PCC allocate the binding label/SID, a PCE MUST set P=0
and include an empty TE-PATH-BINDING TLV ( i.e., no binding value and include an empty TE-PATH-BINDING TLV ( i.e., no binding value
is specified) in the LSP object in PCInitiate/PCUpd message. is specified) in the LSP object in PCInitiate/PCUpd message.
* To request that the PCE allocate the binding label/SID, a PCC MUST * To request that the PCE allocate the binding label/SID, a PCC MUST
set P=1, D=1, and include an empty TE-PATH-BINDING TLV in PCRpt set P=1, D=1, and include an empty TE-PATH-BINDING TLV in PCRpt
message. The PCE SHOULD allocate it and respond to the PCC with message. The PCE will attempt to allocate it and respond to the
PCUpd message including the allocated binding label/SID in the TE- PCC with PCUpd message including the allocated binding label/SID
PATH-BINDING TLV and P=1, D=1 in the LSP object. If the PCE is in the TE-PATH-BINDING TLV and P=1, D=1 in the LSP object. If the
unable to allocate, it MUST send a PCErr message with Error-Type = PCE is unable to allocate, it MUST send a PCErr message with
TBD2 ("Binding label/SID failure") and Error-Value = TBD5 ("Unable Error-Type = TBD2 ("Binding label/SID failure") and Error-Value =
to allocate a new binding label/SID"). TBD5 ("Unable to allocate a new binding label/SID").
* If one or both speakers (PCE and PCC) have not indicated support * If one or both speakers (PCE and PCC) have not indicated support
and willingness to use the PCEP extensions for the PCECC as per and willingness to use the PCEP extensions for the PCECC as per
[RFC9050] and a PCEP peer receives P=1 in the LSP object, it MUST: [RFC9050] and a PCEP peer receives P=1 in the LSP object, it MUST:
- send a PCErr message with Error-Type=19 (Invalid Operation) and - send a PCErr message with Error-Type=19 (Invalid Operation) and
Error-value=16 (Attempted PCECC operations when PCECC Error-value=16 (Attempted PCECC operations when PCECC
capability was not advertised) and capability was not advertised) and
- terminate the PCEP session. - terminate the PCEP session.
skipping to change at page 13, line 17 skipping to change at page 14, line 27
It is assumed that the label range to be used by a PCE is known and It is assumed that the label range to be used by a PCE is known and
set on both PCEP peers. The exact mechanism is out of the scope of set on both PCEP peers. The exact mechanism is out of the scope of
[RFC9050] or this document. Note that the specific BSID could be [RFC9050] or this document. Note that the specific BSID could be
from the PCE-controlled or the PCC-controlled label space. The PCE from the PCE-controlled or the PCC-controlled label space. The PCE
can directly allocate the label from the PCE-controlled label space can directly allocate the label from the PCE-controlled label space
using P=1 as described above, whereas the PCE can request the using P=1 as described above, whereas the PCE can request the
allocation of a specific BSID from the PCC-controlled label space allocation of a specific BSID from the PCC-controlled label space
with P=0 as described in Section 5. with P=0 as described in Section 5.
Note that, the P-Flag in the LSP object SHOULD NOT be set to 1
without the presence of TE-PATH-BINDING TLV or any other future TLV
defined for PCE allocation. On receipt of such an LSP object, the
P-Flag is ignored. The presence of TE-PATH-BINDING TLV with P=1
indicates the allocation is for the binding label/SID. In the
future, some other TLV (such as one defined in
[I-D.ietf-pce-sr-path-segment]) could also be used alongside P=1 to
indicate allocation of a different attribute. A future document
should not attempt to assign semantics to P=1 without limiting its
scope that both PCEP peers could agree on.
9. Implementation Status 9. Implementation Status
[Note to the RFC Editor - remove this section before publication, as [Note to the RFC Editor - remove this section before publication, as
well as remove the reference to RFC 7942.] well as remove the reference to RFC 7942.]
This section records the status of known implementations of the This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942]. Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their be construed to be, a catalog of available implementations or their
skipping to change at page 14, line 20 skipping to change at page 16, line 4
* Organization: Cisco Systems * Organization: Cisco Systems
* Implementation: Head-end and controller. * Implementation: Head-end and controller.
* Description: An experimental code-point is used and will be * Description: An experimental code-point is used and will be
modified to the value allocated in this document. modified to the value allocated in this document.
* Maturity Level: Production * Maturity Level: Production
* Coverage: Full * Coverage: Full
* Contact: mkoldych@cisco.com * Contact: mkoldych@cisco.com
10. Security Considerations 10. Security Considerations
The security considerations described in [RFC5440], [RFC8231], The security considerations described in [RFC5440], [RFC8231],
[RFC8281] and [RFC8664] are applicable to this specification. No [RFC8281], [RFC8664], and [RFC9050] are applicable to this
additional security measure is required. specification. No additional security measure is required.
As described in [RFC8664], SR allows a network controller to As described in [RFC8402] and [RFC8664], SR intrinsically involves an
instantiate and control paths in the network. A rogue PCE can entity (whether head-end or a central network controller) controlling
manipulate binding SID allocations to move traffic around for some and instantiating paths in the network without the involvement of
other LSP that uses BSID in its SR-ERO. Note that path {A, B, BSID} (other) nodes along those paths. Binding SIDs are in effect
can be misdirected just by assigning the BSID value to a different shorthand aliases for longer path representations, and the alias
LSP making it a lot easier to misdirect traffic (and harder to expansion is in principle known only by the node that acts on it. In
detect). this document, the expansion of the alias is shared between PCC and
PCE, and rogue actions by either PCC or PCE could result in shifting
or misdirecting traffic in ways that are hard for other nodes to
detect. In particular, when a PCE propagates paths of the form {A,
B, BSID} to other entities, the BSID values are opaque, and a rogue
PCE can substitute a BSID from a different LSP in such paths to move
traffic without the recipient of the path knowing the ultimate
destination.
Note that in case of BT as 3, the manipulation of SID structure could The case of BT=3 provides additional opportunities for malfeasance,
be exploited by falsifying the various length values. as it purports to convey information about internal SRv6 SID
structure. There is no mechanism defined to validate this internal
structure information, and mischaracterizing the division of bits
into locator block, locator node, function, and argument can result
in different interpretation of the bits by PCC and PCE. Most
notably, shifting bits into or out of the "argument" is a direct
vector for affecting processing, but other attacks are also possible.
Thus, as per [RFC8231], it is RECOMMENDED that these PCEP extensions Thus, as per [RFC8231], it is RECOMMENDED that these PCEP extensions
only be activated on authenticated and encrypted sessions across PCEs only be activated on authenticated and encrypted sessions across PCEs
and PCCs belonging to the same administrative authority, using and PCCs belonging to the same administrative authority, using
Transport Layer Security (TLS) [RFC8253], as per the recommendations Transport Layer Security (TLS) [RFC8253], as per the recommendations
and best current practices in BCP195 [RFC7525] (unless explicitly set and best current practices in BCP195 [RFC7525] (unless explicitly set
aside in [RFC8253]). aside in [RFC8253]).
11. Manageability Considerations 11. Manageability Considerations
skipping to change at page 17, line 4 skipping to change at page 18, line 46
Table 2 Table 2
IANA is requested to create a new subregistry "TE-PATH-BINDING TLV IANA is requested to create a new subregistry "TE-PATH-BINDING TLV
Flag field" to manage the Flag field in the TE-PATH-BINDING TLV. New Flag field" to manage the Flag field in the TE-PATH-BINDING TLV. New
values are to be assigned by Standards Action [RFC8126]. Each bit values are to be assigned by Standards Action [RFC8126]. Each bit
should be tracked with the following qualities: should be tracked with the following qualities:
* Bit number (count from 0 as the most significant bit) * Bit number (count from 0 as the most significant bit)
* Description * Description
* Reference
* Reference
+=====+=============+===============+ +=====+=============+===============+
| Bit | Description | Reference | | Bit | Description | Reference |
+=====+=============+===============+ +=====+=============+===============+
+-----+-------------+---------------+ +-----+-------------+---------------+
| 0 | R (Removal) | This document | | 0 | R (Removal) | This document |
+-----+-------------+---------------+ +-----+-------------+---------------+
| 1-7 | Unassigned | This document | | 1-7 | Unassigned | This document |
+-----+-------------+---------------+ +-----+-------------+---------------+
Table 3 Table 3
12.2. LSP Object 12.2. LSP Object
IANA is requested to confirm the early allocation for a new code- IANA is requested to confirm the early allocation for a new code-
point in the "LSP Object Flag Field" sub-registry for the new P flag point in the "LSP Object Flag Field" sub-registry for the new P flag
as follows: as follows:
+=====+=================================+===============+ +=====+================+===============+
| Bit | Description | Reference | | Bit | Description | Reference |
+=====+=================================+===============+ +=====+================+===============+
+-----+---------------------------------+---------------+ +-----+----------------+---------------+
| 0 | PCE-allocated binding label/SID | This document | | 0 | PCE-allocation | This document |
+-----+---------------------------------+---------------+ +-----+----------------+---------------+
Table 4 Table 4
12.3. PCEP Error Type and Value 12.3. PCEP Error Type and Value
This document defines a new Error-type and associated Error-Values This document defines a new Error-type and associated Error-Values
for the PCErr message. IANA is requested to allocate new error-type for the PCErr message. IANA is requested to allocate new error-type
and error-values within the "PCEP-ERROR Object Error Types and and error-values within the "PCEP-ERROR Object Error Types and
Values" subregistry of the PCEP Numbers registry, as follows: Values" subregistry of the PCEP Numbers registry, as follows:
+============+================+========================+===========+ +============+================+========================+===========+
| Error-Type | Meaning | Error-value | Reference | | Error-Type | Meaning | Error-value | Reference |
skipping to change at page 18, line 23 skipping to change at page 20, line 23
| | | | document | | | | | document |
+------------+----------------+------------------------+-----------+ +------------+----------------+------------------------+-----------+
| | | TBD4: Unable to | This | | | | TBD4: Unable to | This |
| | | allocate the specified | document | | | | allocate the specified | document |
| | | binding value | | | | | binding value | |
+------------+----------------+------------------------+-----------+ +------------+----------------+------------------------+-----------+
| | | TBD5: Unable to | This | | | | TBD5: Unable to | This |
| | | allocate a new binding | document | | | | allocate a new binding | document |
| | | label/SID | | | | | label/SID | |
+------------+----------------+------------------------+-----------+ +------------+----------------+------------------------+-----------+
| | | TBD6: Unable to remove | This |
| | | the binding value | document |
+------------+----------------+------------------------+-----------+
| | | TBD7: Inconsistent | This |
| | | binding types | document |
+------------+----------------+------------------------+-----------+
Table 5 Table 5
13. Acknowledgements 13. Acknowledgements
We would like to thank Milos Fabian, Mrinmoy Das, Andrew Stone, Tom We would like to thank Milos Fabian, Mrinmoy Das, Andrew Stone, Tom
Petch, Aijun Wang, Olivier Dugeon, and Adrian Farrel for their Petch, Aijun Wang, Olivier Dugeon, and Adrian Farrel for their
valuable comments. valuable comments.
Thanks to Julien Meuric for shepherding. Thanks to John Scudder for Thanks to Julien Meuric for shepherding. Thanks to John Scudder for
the AD review. the AD review.
Thanks to Theresa Enghardt for GENART review. Thanks to Theresa Enghardt for the GENART review.
Thanks to Martin Vigoureux, Benjamin Kaduk, Eric Vyncke, Lars Eggert,
Murray Kucherawy, and Erik Kline for the IESG reviews.
14. References 14. References
14.1. Normative References 14.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
skipping to change at page 21, line 5 skipping to change at page 23, line 16
Computation Element (PCE)-Based Architecture", RFC 4655, Computation Element (PCE)-Based Architecture", RFC 4655,
DOI 10.17487/RFC4655, August 2006, DOI 10.17487/RFC4655, August 2006,
<https://www.rfc-editor.org/info/rfc4655>. <https://www.rfc-editor.org/info/rfc4655>.
[RFC8283] Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An [RFC8283] Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An
Architecture for Use of PCE and the PCE Communication Architecture for Use of PCE and the PCE Communication
Protocol (PCEP) in a Network with Central Control", Protocol (PCEP) in a Network with Central Control",
RFC 8283, DOI 10.17487/RFC8283, December 2017, RFC 8283, DOI 10.17487/RFC8283, December 2017,
<https://www.rfc-editor.org/info/rfc8283>. <https://www.rfc-editor.org/info/rfc8283>.
[RFC8669] Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah, [RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
A., and H. Gredler, "Segment Routing Prefix Segment Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
Identifier Extensions for BGP", RFC 8669, (SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
DOI 10.17487/RFC8669, December 2019, <https://www.rfc-editor.org/info/rfc8754>.
<https://www.rfc-editor.org/info/rfc8669>.
[I-D.ietf-spring-segment-routing-policy] [I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", Work in P. Mattes, "Segment Routing Policy Architecture", Work in
Progress, Internet-Draft, draft-ietf-spring-segment- Progress, Internet-Draft, draft-ietf-spring-segment-
routing-policy-14, 25 October 2021, routing-policy-16, 28 January 2022,
<https://www.ietf.org/archive/id/draft-ietf-spring- <https://www.ietf.org/archive/id/draft-ietf-spring-
segment-routing-policy-14.txt>. segment-routing-policy-16.txt>.
[I-D.ietf-pce-pcep-yang] [I-D.ietf-pce-pcep-yang]
Dhody, D., Hardwick, J., Beeram, V. P., and J. Tantsura, Dhody, D., Hardwick, J., Beeram, V. P., and J. Tantsura,
"A YANG Data Model for Path Computation Element "A YANG Data Model for Path Computation Element
Communications Protocol (PCEP)", Work in Progress, Communications Protocol (PCEP)", Work in Progress,
Internet-Draft, draft-ietf-pce-pcep-yang-17, 23 October Internet-Draft, draft-ietf-pce-pcep-yang-18, 25 January
2021, <https://www.ietf.org/archive/id/draft-ietf-pce- 2022, <https://www.ietf.org/archive/id/draft-ietf-pce-
pcep-yang-17.txt>. pcep-yang-18.txt>.
[I-D.li-pce-controlled-id-space]
Li, C., Chen, M., Wang, A., Cheng, W., and C. Zhou, "PCE
Controlled ID Space", Work in Progress, Internet-Draft,
draft-li-pce-controlled-id-space-09, 22 August 2021,
<https://www.ietf.org/archive/id/draft-li-pce-controlled-
id-space-09.txt>.
[I-D.ietf-pce-sr-path-segment]
Li, C., Chen, M., Cheng, W., Gandhi, R., and Q. Xiong,
"Path Computation Element Communication Protocol (PCEP)
Extension for Path Segment in Segment Routing (SR)", Work
in Progress, Internet-Draft, draft-ietf-pce-sr-path-
segment-04, 12 August 2021,
<https://www.ietf.org/archive/id/draft-ietf-pce-sr-path-
segment-04.txt>.
Appendix A. Contributor Addresses Appendix A. Contributor Addresses
Jonathan Hardwick Jonathan Hardwick
Metaswitch Networks Metaswitch Networks
33 Genotin Road 33 Genotin Road
Enfield Enfield
United Kingdom United Kingdom
EMail: Jonathan.Hardwick@metaswitch.com EMail: Jonathan.Hardwick@metaswitch.com
Dhruv Dhody Dhruv Dhody
Huawei Technologies Huawei Technologies
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