PCE Working Group L. Han Internet-Draft Y. Zhao Intended status: Standards Track Y. Liu Expires: 24 April 2025 China Mobile 21 October 2024 PCEP Extension for Fine Grain Optical Transport Network (fgOTN) draft-han-pce-fgotn-pcep-extension-00 Abstract This document introduces the PCEP extension used for computed fgOTN path from the PCE to the PCC. 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 24 April 2025. Copyright Notice Copyright (c) 2024 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 to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Han, et al. Expires 24 April 2025 [Page 1] Internet-Draft fgOTN PCEP Extension October 2024 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements on the PCEP computed path information . . . . . 2 3. PCEP Extention for fgOTN path set-up . . . . . . . . . . . . 3 4. Manageability Considerations . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 7. Normative References . . . . . . . . . . . . . . . . . . . . 4 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction As SDH phases out in operators’ networks, Fine Grain Optical Transport Network (fgOTN) technology complementing the existing OTN with an additional fgOTN path layer network is used as an alternative to carry private line services. A new fine grain ODU layer network has been defined in ITU-T to carry these signals across the OTN networks, to provide flexible N*10Mbps bandwidth TDM-based transport capabilities. ITU-T has a series of recommendations for fgOTN (fine grain OTN ). The fgOTN overview is defined in [ITU-T_G.709.20], fgOTN layer architecture is defined in [ITU-T_G.872], fgOTN Interface and server adaptation is defined in [ITU-T_G.709], fgOTN equipment is defined in[ITU-T_G.798], fgOTN synchronization is defined in [ITU-T_G.8251], fgOTN management requirements is defined in [ITU-T_G.874] and protocol-neutral information model is defined in [ITU-T_G.875]. [RFC8779]provides the PCEP extensions required for GMPLS applications, for example, for Optical Transport Networks (OTNs) and Wavelength Switched Optical Networks (WSONs). Due to the new features of fgOTN technology, PCEP needs to be extended. The requirements were analyzed in [I-D.draft-han-pce-path-computation-fg-transport]. 2. Requirements on the PCEP computed path information For each computed fgOTN path, the information carried by the PCEP should at least include: 1) fgOTN path information 2) fgOTN path protection type 3) Path role (working path/backup path) 4) fgOTN path bandwidth 5) fgOTN path list: a) node identifier b) Path identifier Han, et al. Expires 24 April 2025 [Page 2] Internet-Draft fgOTN PCEP Extension October 2024 3. PCEP Extention for fgOTN path set-up The centralized computation model of PCE architecture seems to be suitable for the fine-granularity transport network, while the PCEP (PCE communication protocol) needs to be extended to meet the fine- granularity transport requirements. The protocol and signaling should support the application of fine- granularity path set-up/update/removal and resource management. The extention for fgOTN path set-up is suggested as follows: +==============+========+=========================================+ | Attribute | Length | Value | | | (bits) | | +==============+========+=========================================+ | Connection | 96 | Composed of three tuples (Source Node | | Identifier | | Identifier, Destination Node | | (LSP Object) | | Identifier, Service Index, each 32 | | | | bits) | +--------------+--------+-----------------------------------------+ | Protection | 8 | Includes 1+1 Protection, 1+1, Path | | Type (LSPA | | Protection, No Protection, etc. | | Object's | | | | Protection | | | | Attributes) | | | +--------------+--------+-----------------------------------------+ | Primary/ | 8 | Set to 1 to indicate working path, set | | Backup Flag | | to 0 to indicate protection path | | (LSPA | | | | Object, | | | | Protection | | | | Attributes) | | | +--------------+--------+-----------------------------------------+ | Small | 8 | Timeslot granularity, requires fgOTN's | | timeslot | | timeslot granularity. Timeslot | | granularity | | granularity is defined by YD/T | | (Generalized | | 4856-2024 and ITU-T G.709.20 standards; | | Bandwidth | | 0 – 10Mbps (fgOTN) | | Object) | | | +--------------+--------+-----------------------------------------+ | fgOTN | 16 | Integer, expressed in terms of the | | Bandwidth | | number of time slots | | (Generalized | | | | Bandwidth | | | | Object) | | | +--------------+--------+-----------------------------------------+ | Routing | See | Destination node identifier, fgOTN's | Han, et al. Expires 24 April 2025 [Page 3] Internet-Draft fgOTN PCEP Extension October 2024 | Information | Table2 | ingress/egress fgOTN channel number | | (LIST) | | length is 10 bits Refer to RFC5440 for | | | | RP object's B Flag bit to determine | | | | simplex or duplex. For simplex | | | | connections, routing information (LIST) | | | | will generate unidirectional exchanges. | | | | For duplex connections, routing | | | | information for both ingress and egress | | | | will generate bidirectional exchanges. | +--------------+--------+-----------------------------------------+ Table 1: Service provisioning Initiate/Update message coding format (from control system to signaling head node) +==========================================+===============+ | Attribute | Length (bits) | +==========================================+===============+ | Network Element Identifier | 32 | +------------------------------------------+---------------+ | Ingress | 32 | +------------------------------------------+---------------+ | Ingress ODU Service Layer Channel Number | 16 | +------------------------------------------+---------------+ | Ingress fgOTN Channel Number | 16 | +------------------------------------------+---------------+ | Egress | 32 | +------------------------------------------+---------------+ | Egress ODU Service Layer Channel Number | 16 | +------------------------------------------+---------------+ | Egress fgOTN Channel Number | 16 | +------------------------------------------+---------------+ Table 2: Routing Information Instance 4. Manageability Considerations 5. Security Considerations 6. IANA Considerations 7. Normative References Han, et al. Expires 24 April 2025 [Page 4] Internet-Draft fgOTN PCEP Extension October 2024 [I-D.draft-han-pce-path-computation-fg-transport] Han, L., Zheng, H., Wang, M., and Y. Zhao, "Path Computation and Control Extention Requirements for Fine- Granularity Transport Network", Work in Progress, Internet-Draft, draft-han-pce-path-computation-fg- transport, March 2024, . [ITU-T_G.709] International Telecommunication Union, "Interfaces for the optical transport network", ITU-T Recommendation G.709 , July 2024. [ITU-T_G.709.20] International Telecommunication Union, "Overview of fine grain OTN", ITU-T Recommendation G.709.20 , April 2024. [ITU-T_G.798] International Telecommunication Union, "Characteristics of optical transport network hierarchy equipment functional blocks", ITU-T Recommendation G.798 , September 2023. [ITU-T_G.8251] International Telecommunication Union, "The control of jitter and wander within the optical transport network (OTN)", ITU-T Recommendation G.8251 , November 2022. [ITU-T_G.872] International Telecommunication Union, "Architecture of the optical transport network", ITU-T Recommendation G.872 , March 2024. [ITU-T_G.874] International Telecommunication Union, "Management aspects of optical transport network elements", ITU-T Recommendation G.874 , October 2020. [ITU-T_G.875] International Telecommunication Union, "Optical transport network: Protocol-neutral management information model for the network element view", ITU-T Recommendation G.875 , June 2020. Han, et al. Expires 24 April 2025 [Page 5] Internet-Draft fgOTN PCEP Extension October 2024 [RFC8779] Margaria, C., Ed., Gonzalez de Dios, O., Ed., and F. Zhang, Ed., "Path Computation Element Communication Protocol (PCEP) Extensions for GMPLS", RFC 8779, DOI 10.17487/RFC8779, July 2020, . Acknowledgments Authors' Addresses Liuyan Han China Mobile Email: hanliuyan@chinamobile.com Yang Zhao China Mobile Email: zhaoyangyjy@chinamobile.com Yucong Liu China Mobile Email: liuyucongyjy@chinamobile.com Han, et al. Expires 24 April 2025 [Page 6]