Internet DRAFT - draft-paul-pce-rsvp-spring-migration
draft-paul-pce-rsvp-spring-migration
PCE Arijit Paul
Internet-Draft Juniper Networks
Intended status: Standards Track August 30, 2017
Expires: March 3, 2018
PCEP extension to support service migration from rsvp to spring or vice
versa
draft-paul-pce-rsvp-spring-migration-01
Abstract
In a SDN environment, path computation element protocol(PCEP)
(RFC 5440) is used between a controller and the network devices,
using which controller can setup and tear down Resource ReserVation
Protocol (RSVP) based label switched paths(LSPs) in the network
having Path Computation Client (PCC) as Label Switched Router (LSR).
Draft draft-sivabalan-pce-segment-routing extends PCEP specification
in order to support setup and teardown of Segment Routing(SR) Label
Switched Path(LSR). In a mixed environment where some of the LSPs are
setup using PCEP use RSVP and some LSPs are based on Segment
routing(SR). The specifications lacks a method to advertise the
LSP preferenace to use one type of LSP over other when those are
setup using PCEP. This draft defines a method to advertise the
preference for any LSP which is setup using PCEP.
This document proposes new optional TLV that can be used to announce
the preference of LSP which is being setup using PCEP.
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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Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 8, 2018
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Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 3
3. TLV extension to support LSP preference . . . . . . . . . . . 3
3.1. LSP preference TLV . . . . . . . . . . . . . . . . . . . 4
4. Backward Compatibility Consideration . . . . . . . . . . . . 4
5. Management Considerations . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
As described in [RFC5440], PCEP can be used to create, modify or
delete LSPs betweeen PCCs. PCEP can be used to create, modify and
delete RSVP and segment routing LSPs between PCCs. This document
specifies the way to communicate the LSP preference to PCC so that
correct LSP can be used by the MPLS services based on operator need.
This is specially needed in case of migration of services from RSVP
to SR LSP in a phased manner.
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[RFC5440], [draft-crabbe-pce-pce-initiated-lsp] and
[draft-sivabalan-pce-segment-routing] define a method to create,
delete and modify RSVP and segment routing LSPs using PCEP as
communication protocol with PCC. However [RFC5440],
[draft-crabbe-pce-pce-initiated-lsp] and
[draft-sivabalan-pce-segment-routing] lacks a method to specify the
preference for the LSPs which is useful in case operator wants to
seamlessless migrate from RSVP to segment routed LSPs or vice versa.
This document proposes new TLV inside LSP object to carry the
preference value for the particular LSP. LSP objects are carried in
PCRpt, PCUpd [draft-tang-pce-stateful-pce] section 6 and PCInitiate
[draft-crabbe-pce-pce-initiated-lsp] section 5.
2. Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC2119 [RFC2119].
3. TLV extension to support LSP preference
The LSP object is defined in section 7.3 of
[draft-ietf-pce-stateful-pce]. In this section, we extend the LSP
object to include optional TLV to carry the LSP preference.
The format of the LSP object body is shown in Figure 1:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PLSP-ID | Flag | O|A|R|S|D|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// TLVs //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: The LSP Object format
3.1. LSP preference TLV
The LSP preference value TLV is an optional TLV for use in the
LSP object to convey LSP preference value. When an LSP is
created/modified in PCC using PCEP, this TLV may be carried in the
LSP object. When it is carried in the LSP object the preference value
for this particular LSP is set to the preference carried in the TLV.
It overwrites any local preference value set for RSVP or segment
routing LSP in the PCC.
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The format of the LSP-PREFERENCE-VALUE TLV is shown in the following
figure:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=[TBD] | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSP preference value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: LSP-PREFERENCE-VALUE TLV format
The type of the TLV is to be assigned by IANA and it has a fixed
length of 4 octets. The LSP prefernce value contains a number that
indicates preference for that LSP.
4. Backward Compatibility Consideration
A PCC that does not support the new LSP prefernce TLV
specified in this document silently ignores those bits.
PCEP extensions defined in this document do not introduce any new
interoperability issues.
5. Management Considerations
A configuration option may be provided for accepting these preference
changes.
6. Security Considerations
This document raises no new security issues.
7. IANA Considerations
IANA is requested to allocate a Type for this new TLV for LSP
preference support capability.
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8. References
8.1. Normative References
[draft-crabbe-pce-pce-initiated-lsp] E. Crabbe, "PCEP Extensions
for PCE-initiated LSP Setup
in a Stateful PCE Model"
[draft-sivabalan-pce-segment-routing] E. Crabbe, "PCEP Extensions
for Stateful PCE"
8.2. Informative References
[RFC4657] Ash, J. and J. Le Roux, "Path Computation Element (PCE)
Communication Protocol Generic Requirements", RFC 4657,
September 2006.
[RFC5440] Le Roux, JL., "Path Computation Element (PCE)
Communication Protocol (PCEP)", RFC 5440, March 2009.
[RFC2119] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997
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Author's Addresses
Arijit Paul
10214 Parkwood Dr. Apt 5
Cupertino, CA - 95014
USA
Email: arijitp@juniper.net
