PCEP Procedures and Protocol Extensions for Using PCE as a Central Controller (PCECC) for SRv6
draft-dhody-pce-pcep-extension-pce-controller-srv6-05
PCE Working Group Z. Li
Internet-Draft S. Peng
Intended status: Standards Track X. Geng
Expires: May 5, 2021 Huawei Technologies
M. Negi
RtBrick Inc
November 1, 2020
PCEP Procedures and Protocol Extensions for Using PCE as a Central
Controller (PCECC) for SRv6
draft-dhody-pce-pcep-extension-pce-controller-srv6-05
Abstract
The Path Computation Element (PCE) is a core component of Software-
Defined Networking (SDN) systems. It can compute optimal paths for
traffic across a network and can also update the paths to reflect
changes in the network or traffic demands.
PCE was developed to derive paths for MPLS Label Switched Paths
(LSPs), which are supplied to the head end of the LSP using the Path
Computation Element Communication Protocol (PCEP). But SDN has a
broader applicability than signaled (G)MPLS traffic-engineered (TE)
networks, and the PCE may be used to determine paths in a range of
use cases. PCEP has been proposed as a control protocol for use in
these environments to allow the PCE to be fully enabled as a central
controller.
A PCE-based Central Controller (PCECC) can simplify the processing of
a distributed control plane by blending it with elements of SDN and
without necessarily completely replacing it. This document specifies
the procedures and PCEP protocol extensions when a PCE-based
controller is also responsible for configuring the forwarding actions
on the routers for Segment Routing (SR) in IPv6 (SRv6), in addition
to computing the SRv6 paths for packet flows and telling the edge
routers what instructions to attach to packets as they enter the
network.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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Task Force (IETF). Note that other groups may also distribute
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Drafts is at https://datatracker.ietf.org/drafts/current/.
Li, et al. Expires May 5, 2021 [Page 1]
Internet-Draft PCECC-SRv6 November 2020
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 May 5, 2021.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. PCECC SRv6 . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. PCEP Requirements . . . . . . . . . . . . . . . . . . . . . . 6
5. Procedures for Using the PCE as a Central Controller (PCECC)
in SRv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Stateful PCE Model . . . . . . . . . . . . . . . . . . . 6
5.2. New Functions . . . . . . . . . . . . . . . . . . . . . . 6
5.3. PCECC Capability Advertisement . . . . . . . . . . . . . 7
5.4. PCEP session IP address and TED Router ID . . . . . . . . 7
5.5. SRv6 Path Operations . . . . . . . . . . . . . . . . . . 7
5.5.1. PCECC Segment Routing in IPv6 (SRv6) . . . . . . . . 7
5.5.1.1. PCECC SRv6 Node/Prefix SID allocation . . . . . . 8
5.5.1.2. PCECC SRv6 Adjacency SID allocation . . . . . . . 8
5.5.1.3. Redundant PCEs . . . . . . . . . . . . . . . . . 9
5.5.1.4. Re-Delegation and Clean up . . . . . . . . . . . 9
5.5.1.5. Synchronization of SRv6 SID Allocations . . . . . 9
6. PCEP Messages . . . . . . . . . . . . . . . . . . . . . . . . 9
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