Ability for a Stateful Path Computation Element (PCE) to Request and Obtain Control of a Label Switched Path (LSP)
RFC 8741
| Document | Type | RFC - Proposed Standard (March 2020; No errata) | |
|---|---|---|---|
| Authors | Aswatnarayan Raghuram , Al Goddard , Jay Karthik , Siva Sivabalan , Mahendra Negi | ||
| Last updated | 2020-03-09 | ||
| Replaces | draft-raghu-pce-lsp-control-request | ||
| Stream | Internent Engineering Task Force (IETF) | ||
| Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Hariharan Ananthakrishnan | ||
| Shepherd write-up | Show (last changed 2019-06-25) | ||
| IESG | IESG state | RFC 8741 (Proposed Standard) | |
| Action Holders |
(None)
|
||
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Deborah Brungard | ||
| Send notices to | Hariharan Ananthakrishnan <hari@netflix.com> | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) A. Raghuram
Request for Comments: 8741 A. Goddard
Category: Standards Track AT&T
ISSN: 2070-1721 J. Karthik
S. Sivabalan
Cisco Systems, Inc.
M. Negi
Huawei Technologies
March 2020
Ability for a Stateful Path Computation Element (PCE) to Request and
Obtain Control of a Label Switched Path (LSP)
Abstract
A stateful Path Computation Element (PCE) retains information about
the placement of Multiprotocol Label Switching (MPLS) Traffic
Engineering Label Switched Paths (TE LSPs). When a PCE has stateful
control over LSPs, it may send indications to LSP head-ends to modify
the attributes (especially the paths) of the LSPs. A Path
Computation Client (PCC) that has set up LSPs under local
configuration may delegate control of those LSPs to a stateful PCE.
There are use cases in which a stateful PCE may wish to obtain
control of locally configured LSPs that it is aware of but have not
been delegated to the PCE.
This document describes an extension to the Path Computation Element
Communication Protocol (PCEP) to enable a PCE to make requests for
such control.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc8741.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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described in the Simplified BSD License.
Table of Contents
1. Introduction
2. Terminology
2.1. Requirements Language
3. LSP Control Request Flag
4. Operation
5. Security Considerations
6. IANA Considerations
7. Manageability Considerations
7.1. Control of Function and Policy
7.2. Information and Data Models
7.3. Liveness Detection and Monitoring
7.4. Verify Correct Operations
7.5. Requirements on Other Protocols
7.6. Impact on Network Operations
8. References
8.1. Normative References
8.2. Informative References
Acknowledgements
Contributors
Authors' Addresses
1. Introduction
"Path Computation Element Communication Protocol (PCEP) Extensions
for Stateful PCE" [RFC8231] specifies a set of extensions to PCEP
[RFC5440] to enable stateful control of Traffic Engineering Label
Switched Paths (TE LSPs) between and across PCEP sessions in
compliance with [RFC4657]. It includes mechanisms to synchronize LSP
state between Path Computation Clients (PCCs) and PCEs, delegate
control of LSPs to PCEs, and allow PCEs to control the timing and
sequence of path computations within and across PCEP sessions. The
stateful PCEP defines the following two useful network operations:
Delegation: As per [RFC8051], an operation to grant a PCE temporary
rights to modify a subset of LSP parameters on one or
more LSPs of a PCC. LSPs are delegated from a PCC to a
PCE and are referred to as "delegated" LSPs.
Revocation: As per [RFC8231], an operation performed by a PCC on a
previously delegated LSP. Revocation revokes the rights
granted to the PCE in the delegation operation.
For redundant stateful PCEs (Section 5.7.4 of [RFC8231]), during a
PCE failure, one of the redundant PCEs might want to request to take
control over an LSP. The redundant PCEs may use a local policy or a
proprietary election mechanism to decide which PCE would take
control. In this case, a mechanism is needed for a stateful PCE to
request control of one or more LSPs from a PCC so that a newly
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