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 working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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 March 8, 2018 Paul Expires March 8, 2018 [Page 1] Internet-Draft LSP preference for PCEP August 2017 Copyright Notice Copyright (c) 2016 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 Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. 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. Paul Expires March 8, 2018 [Page 2] Internet-Draft LSP preference for PCEP August 2017 [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. Paul Expires March 8, 2018 [Page 3] Internet-Draft LSP preference for PCEP August 2017 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. Paul Expires March 8, 2018 [Page 4] Internet-Draft LSP preference for PCEP August 2017 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 Paul Expires March 8, 2018 [Page 5] Internet-Draft LSP preference for PCEP August 2017 Author's Addresses Arijit Paul 10214 Parkwood Dr. Apt 5 Cupertino, CA - 95014 USA Email: arijitp@juniper.net