PCE Working Group D. Dhody Internet-Draft Huawei Technologies Intended status: Standards Track September 25, 2016 Expires: March 29, 2017 Conveying Vendor-Specific Information in the Path Computation Element (PCE) Communication Protocol (PCEP) extensions for stateful PCE. draft-dhody-pce-stateful-pce-vendor-01 Abstract A Stateful Path Computation Element (PCE) maintains information on the current network state, including: computed Label Switched Path (LSPs), reserved resources within the network, and pending path computation requests. This information may then be considered when computing new traffic engineered LSPs, and for associated and dependent LSPs, received from Path Computation Clients (PCCs). RFC 7470 defines a facility to carry vendor-specific information in PCEP. This document extends this capability for stateful PCE. 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 29, 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 Dhody Expires March 29, 2017 [Page 1] Internet-Draft VENDOR-STATEFUL September 2016 (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 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Procedures for the Vendor Information Object . . . . . . . . 3 3. Procedures for the Vendor Information TLV . . . . . . . . . . 5 4. Vendor Information Object and TLV . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . 6 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . 6 8.2. Informative References . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction The Path Computation Element communication Protocol (PCEP) [RFC5440] provides mechanisms for Path Computation Elements (PCEs) to perform path computations in response to Path Computation Clients' (PCCs) requests. A stateful PCE is capable of considering, for the purposes of path computation, not only the network state in terms of links and nodes (referred to as the Traffic Engineering Database or TED) but also the status of active services (previously computed paths, and currently reserved resources, stored in the Label Switched Paths Database (LSPDB). [I-D.ietf-pce-stateful-pce-app] describes general considerations for a stateful PCE deployment and examines its applicability and benefits, as well as its challenges and limitations through a number of use cases. [I-D.ietf-pce-stateful-pce] describes a set of extensions to PCEP to provide stateful control. A stateful PCE has access to not only the information carried by the network's Interior Gateway Protocol (IGP), but also the set of active paths and their reserved resources for its computations. The additional state allows the PCE to compute constrained paths while considering individual LSPs and their interactions. [I-D.ietf-pce-pce-initiated-lsp] describes the setup, Dhody Expires March 29, 2017 [Page 2] Internet-Draft VENDOR-STATEFUL September 2016 maintenance and teardown of PCE-initiated LSPs under the stateful PCE model. These extensions added new messages in PCEP. [RFC7470] defined Vendor Information object that can be used to carry arbitrary, proprietary information such as vendor-specific constraints. It also defined VENDOR-INFORMATION-TLV that can be used to carry arbitrary information within any existing or future PCEP object that supports TLVs. This document extend the usage of Vendor Information Object and VENDOR-INFORMATION-TLV to stateful PCE. 1.1. Requirements Language 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]. 2. Procedures for the Vendor Information Object A Path Computation LSP State Report message (also referred to as PCRpt message) is a PCEP message sent by a PCC to a PCE to report the current state of an LSP. A PCC that wants to convey proprietary or vendor-specific information or metrics to a PCE does so by including a Vendor Information object in the PCRpt message. The contents and format of the object are described in Section 4 of [RFC7470]. The PCE determines how to interpret the information in the Vendor Information object by examining the Enterprise Number it contains. The Vendor Information object is OPTIONAL in a PCRpt message. Multiple instances of the object MAY be used on a single PCRpt message. Different instances of the object can have different Enterprise Numbers. The format of the PCRpt message (with [I-D.ietf-pce-stateful-pce] as base) is updated as follows Dhody Expires March 29, 2017 [Page 3] Internet-Draft VENDOR-STATEFUL September 2016 ::= Where: ::= [] ::= [] [] Where: ::= [] is defined in [I-D.ietf-pce-stateful-pce]. A Path Computation LSP Update Request message (also referred to as PCUpd message) is a PCEP message sent by a PCE to a PCC to update attributes of an LSP. The Vendor Information object can be included in a PCUpd message to convey proprietary or vendor-specific information. The format of the PCUpd message (with [I-D.ietf-pce-stateful-pce] as base) is updated as follows ::= Where: ::= [] ::= [] Where: ::= [] is defined in [I-D.ietf-pce-stateful-pce]. A Path Computation LSP Initiate Message (also referred to as PCInitiate message) is a PCEP message sent by a PCE to a PCC to trigger LSP instantiation or deletion. The Vendor Information object can be included in a PCInitiate message to convey proprietary or vendor-specific information. The format of the PCInitiate message (with [I-D.ietf-pce-pce-initiated-lsp] as base) is updated as follows Dhody Expires March 29, 2017 [Page 4] Internet-Draft VENDOR-STATEFUL September 2016 ::= Where: ::= [] ::= ( |) ::= [] [] ::= Where: ::= [] and is as per [I-D.ietf-pce-pce-initiated-lsp]. A legacy implementation that does not recognize the Vendor Information object will act according to the procedures set out in [I-D.ietf-pce-stateful-pce] and [I-D.ietf-pce-pce-initiated-lsp]. An implementation that supports the Vendor Information object, but receives one carrying an Enterprise Number that it does not support, SHOULD ignore the object. 3. Procedures for the Vendor Information TLV The Vendor Information TLV can be used to carry vendor-specific information that applies to a specific PCEP object by including the TLV in the object. This includes objects used in stateful PCE extension such as SRP and LSP object. All the procedures as per section 3 of [RFC7470]. 4. Vendor Information Object and TLV [RFC7470] specify the format of VENDOR-INFORMATION Object and VENDOR- INFORMATION-TLV. Dhody Expires March 29, 2017 [Page 5] Internet-Draft VENDOR-STATEFUL September 2016 5. IANA Considerations There are no IANA consideration. 6. Security Considerations The protocol extensions defined in this document do not change the nature of PCEP. Therefore, the security considerations set out in [RFC5440], [RFC7470], [I-D.ietf-pce-stateful-pce] and [I-D.ietf-pce-pce-initiated-lsp] apply unchanged. Note that further security considerations for the use of PCEP over TCP are presented in [RFC6952]. 7. Acknowledgments Thanks to Avantika, Mahendra Singh Negi, Udayasree Palle and Swapna K for their suggestions. 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009, . [RFC7470] Zhang, F. and A. Farrel, "Conveying Vendor-Specific Constraints in the Path Computation Element Communication Protocol", RFC 7470, DOI 10.17487/RFC7470, March 2015, . [I-D.ietf-pce-stateful-pce] Crabbe, E., Minei, I., Medved, J., and R. Varga, "PCEP Extensions for Stateful PCE", draft-ietf-pce-stateful- pce-16 (work in progress), September 2016. [I-D.ietf-pce-pce-initiated-lsp] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model", draft-ietf-pce-pce-initiated-lsp-07 (work in progress), July 2016. Dhody Expires March 29, 2017 [Page 6] Internet-Draft VENDOR-STATEFUL September 2016 8.2. Informative References [RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, . [I-D.ietf-pce-stateful-pce-app] Zhang, X. and I. Minei, "Applicability of a Stateful Path Computation Element (PCE)", draft-ietf-pce-stateful-pce- app-06 (work in progress), July 2016. Author's Address Dhruv Dhody Huawei Technologies Divyashree Techno Park, Whitefield Bangalore, Karnataka 560066 India EMail: dhruv.ietf@gmail.com Dhody Expires March 29, 2017 [Page 7]