PCE Q. Xiong Internet-Draft ZTE Corporation Intended status: Standards Track March 8, 2021 Expires: September 9, 2021 LSP Object Flag Extension of Stateful PCE draft-ietf-pce-lsp-extended-flags-00 Abstract RFC 8231 describes a set of extensions to Path Computation Element Communication Protocol (PCEP) to enable stateful control of MPLS-TE and GMPLS Label Switched Paths(LSPs) via PCEP. One of the extensions is the LSP object which includes a Flag field of the length of 12 bits. However, 11 bits of the Flag field have already been assigned in RFC 8231, RFC 8281 and RFC 8623. This document proposes to define a new LSP-EXTENDED-FLAG TLV for the LSP object for an extended flag field. 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 https://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 September 9, 2021. Copyright Notice Copyright (c) 2021 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 (https://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 Xiong Expires September 9, 2021 [Page 1] Internet-Draft LSP Object Flag Extension of Stateful PCE March 2021 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 2.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Requirements Language . . . . . . . . . . . . . . . . . . 3 3. PCEP Extension . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. The LSP-EXTENDED-FLAG TLV . . . . . . . . . . . . . . . . 3 3.2. Processing . . . . . . . . . . . . . . . . . . . . . . . 4 4. Backward Compatibility . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5.1. LSP Object . . . . . . . . . . . . . . . . . . . . . . . 4 5.1.1. PCEP TLV Type Indicators . . . . . . . . . . . . . . 4 5.1.2. LSP Extended Flags Field . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 5 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 9.1. Normative References . . . . . . . . . . . . . . . . . . 5 9.2. Informative References . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction [RFC5440] describes the Path Computation Element Protocol (PCEP) which is used between a Path Computation Element (PCE) and a Path Computation Client (PCC) (or other PCE) to enable computation of Multi-protocol Label Switching (MPLS) for Traffic Engineering Label Switched Path (TE LSP). PCEP Extensions for the Stateful PCE Model [RFC8231] describes a set of extensions to PCEP to enable active control of MPLS-TE and Generalized MPLS (GMPLS) tunnels. One of the extensions is the LSP object which contains a flag field; bits in the flag field are used to indicate delegation, syncronization, removal, etc. As defined in [RFC8231], the length of the flag field is 12 bits and the value from bit 5 to bit 11 is used for operational, administrative, remove, synchronize and delegate bits respectively. The bit value 4 is assigned in [RFC8281] for create for PCE-Initiated LSPs. The bits from 1 to 3 is assigned in [RFC8623] for Explicit Route Object (ERO)-compression, fragmentation and Point-to-Multipoint (P2MP) respectively. Almost all bits of the Flag field has been Xiong Expires September 9, 2021 [Page 2] Internet-Draft LSP Object Flag Extension of Stateful PCE March 2021 assigned already. Thus, it is required to extend the flag field for the LSP Object for future use. This document proposes to define a new LSP-EXTENDED-FLAG TLV for an extended flag field in the LSP object. 2. Conventions used in this document 2.1. Terminology The terminology is defined as [RFC5440] and [RFC8231]. 2.2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. PCEP Extension The LSP Object is defined in Section 7.3 of [RFC8231]. This document proposes to define a new LSP-EXTENDED-FLAG TLV for an extended flag field in the LSP object. 3.1. The LSP-EXTENDED-FLAG TLV The format of the LSP-EXTENDED-FLAG TLV is as shown in the 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type=TBD | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | // LSP Extended Flags // | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: LSP-EXTENDED-FLAG TLV Format Type (16 bits): the value is TBD1 by IANA. Length (16 bits): multiple of 4 octets. Xiong Expires September 9, 2021 [Page 3] Internet-Draft LSP Object Flag Extension of Stateful PCE March 2021 LSP Extended Flags: this contains an array of units of 32-bit flags numbered from the most significant as bit zero, where each bit represents one LSP operation, feature, or state. Currently no bits are assigned. Unassigned bits MUST be set to zero on transmission and MUST be ignored on receipt. 3.2. Processing The LSP Extended Flags field is an array of units of 32 flags and to be allocated starting from the most significant bit. No bits are currently assigned in this document and the bits of the LSP Extended Flags field will be assigned by future documents. 4. Backward Compatibility The LSP-EXTENDED-FLAG TLV defined in this document does not introduce any interoperability issues. A router that does not understand or support the LSP-EXTENDED-FLAG TLV will silently ignore the TLV as per [RFC5440]. It is expected that future document that define bits in the LSP-EXTENDED-FLAG TLV would also define the error case handling required for missing LSP- EXTENDED-FLAG TLV. 5. IANA Considerations 5.1. LSP Object 5.1.1. PCEP TLV Type Indicators IANA is requested to allocate the following TLV Type Indicator value within the "PCEP TLV Type Indicators" subregistry of the "Path Computation Element Protocol (PCEP) Numbers" registry: Value Description Reference TBD1 LSP-EXTENDED-FLAG [This document] 5.1.2. LSP Extended Flags Field IANA is requested to create a new subregistry called "LSP-EXTENDED- FLAG TLV Flag Field", within the "Path Computation Element Protocol (PCEP) Numbers" registry to manage the LSP Extended Flags field of the LSP-EXTENDED-FLAG TLV. New values are assigned by Standards Action [RFC8126]. Each bit should be tracked with the following qualities: o Bit number (counting from bit 0 as the most significant bit) Xiong Expires September 9, 2021 [Page 4] Internet-Draft LSP Object Flag Extension of Stateful PCE March 2021 o Capability description o Defining RFC No values are currently defined. 6. Security Considerations For LSP Object procssing security considerations, see [RFC8231]. No additional security issues are raised in this document beyond those that exist in the referenced documents. 7. Acknowledgements The authors would like to thank Loa Andersson and Adrian Farrel for their review, suggestions and comments to this document. 8. Contributors The following people have contributed to this document: Dhruv Dhody EMail: dhruv.ietf@gmail.com 9. References 9.1. 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, . [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . Xiong Expires September 9, 2021 [Page 5] Internet-Draft LSP Object Flag Extension of Stateful PCE March 2021 [RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for Stateful PCE", RFC 8231, DOI 10.17487/RFC8231, September 2017, . 9.2. Informative References [RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for PCE-Initiated LSP Setup in a Stateful PCE Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, . [RFC8623] Palle, U., Dhody, D., Tanaka, Y., and V. Beeram, "Stateful Path Computation Element (PCE) Protocol Extensions for Usage with Point-to-Multipoint TE Label Switched Paths (LSPs)", RFC 8623, DOI 10.17487/RFC8623, June 2019, . Author's Address Quan Xiong ZTE Corporation No.6 Huashi Park Rd Wuhan, Hubei 430223 China Email: xiong.quan@zte.com.cn Xiong Expires September 9, 2021 [Page 6]