LSR Q. Xiong Internet-Draft X. Zhu Intended status: Standards Track ZTE Corporation Expires: 29 December 2024 27 June 2024 IGP Extensions for Deterministic Link draft-xiong-lsr-deterministic-link-00 Abstract This document proposes the deterministic link to provide an one- dimensional metric to indicate the deterministic forwarding capabilities at different levels and proposes the deterministic links distribution by IGP extensions. 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 29 December 2024. 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. Xiong & Zhu Expires 29 December 2024 [Page 1] Internet-Draft IGP Extensions for Deterministic Link June 2024 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Deterministic Link . . . . . . . . . . . . . . . . . . . . . 3 3.1. Deterministic Link Model . . . . . . . . . . . . . . . . 3 3.2. Classification of Deterministic Links . . . . . . . . . . 4 4. ISIS Extensions of Deterministic Link . . . . . . . . . . . . 5 4.1. Deterministic Link Sub-TLV . . . . . . . . . . . . . . . 5 4.1.1. Deterministic Link Maximum Reservable Bandwidth Sub-sub-TLV . . . . . . . . . . . . . . . . . . . . . 6 4.1.2. Deterministic Link Available Bandwidth Sub-sub-TLV . 7 4.1.3. Deterministic Link Delay Sub-sub-TLV . . . . . . . . 7 5. OSPF Extensions of Deterministic Links . . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 9.1. Normative References . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction According to [RFC8655], Deterministic Networking (DetNet) operates at the IP layer and delivers service which provides extremely low data loss rates and bounded latency within a network domain. The bounded latency indicates the minimum and maximum end-to-end latency from source to destination and bounded jitter (packet delay variation). [I-D.ietf-detnet-scaling-requirements] has described the enhanced requirements for DetNet enhanced data plane including the deterministic latency guarantees. As per [I-D.ietf-detnet-controller-plane-framework], network nodes need to collect topology information and deterministic capabilities through IGP. Xiong & Zhu Expires 29 December 2024 [Page 2] Internet-Draft IGP Extensions for Deterministic Link June 2024 The computing method of end-to-end delay bounds is defined in [RFC9320]. It is the sum of the six delays in bounded latency model. It is the sum of non-queuing delay bound and queuing delay bound. The upper bounds of queuing delay depends on the queuing mechanisms deployed along the path. For example, a link with a queuing mechanism that does not guarantee a bounded delay is a non- deterministic link and a link with a time-based queuing mechanism that can provide deterministic latency guarantee is called a deterministic link. The delay of a deterministic link is consist of the propagation delay of the packet on the link and the queuing delay of the packet at the node. A deterministic link can be a sub-network that provides deterministic transmission or a Point-to-Point (P2P) link. This document proposes the deterministic link to provide an one- dimensional metric to indicate the deterministic forwarding capabilities at different levels and proposes the deterministic links distribution by IGP extensions. 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 RFC 2119 [RFC2119]. 2. Terminology The terminology is defined as [RFC8655] and [RFC9320]. 3. Deterministic Link This document proposes the deterministic link to provide an one- dimensional metric to indicate the deterministic forwarding capabilities at different levels. The deterministic links can shield the differences from underlying forwarding mechanisms. 3.1. Deterministic Link Model As per [RFC9320], six types of delays are defined in timing Model of DetNet. And the DetNet domain can also be modeling as deterministic links and nodes as shown in Figure 1. The deterministic node delay is constant while the deterministic link delay is variable within bounded latency. The end-to-end bounded latency depends on the sum of the deterministic link delay. * Deterministic Link Delay = Regulation delay + Queuing subsystem delay + Output delay + Link delay + Frame preemption delay Xiong & Zhu Expires 29 December 2024 [Page 3] Internet-Draft IGP Extensions for Deterministic Link June 2024 * Deterministic Node Delay = Processing delay DetNet transit node A DetNet transit node B +-------------------------+ +------------------------+ | Queuing | | Queuing | | Regulator subsystem | | Regulator subsystem | | +-+-+-+-+ +-+-+-+-+ | | +-+-+-+-+ +-+-+-+-+ | -->+ | | | | | | | | | + +------------>+ | | | | | | | | | + +---> | +-+-+-+-+ +-+-+-+-+ | | +-+-+-+-+ +-+-+-+-+ | | | | | +-------------------------+ +------------------------+ |-->|------->|------->|-->|------------>|-->|------->|------>|-->|-->| 2,3 4 5 6 1 2,3 4 5 6 1 2,3 |---- Deterministic Link Delay ---->| Deterministic Links Deterministic Node | A |---------------------------------->| B |----------------------->| Figure 1: Deterministic Link Model 3.2. Classification of Deterministic Links There are a number of deterministic links between deterministic nodes. And each deterministic link provides different level of deterministic forwarding capabilities indicated by Deterministic Class-Type (DT). Deterministic Class-Type (DT): indicate the set of Traffic Trunks crossing a deterministic link that is governed by a specific set of bounded latency constraints and QoS requirements of deterministic guarantees such as tight jitter,strict latency, loose latency and so on. DT is used for the purposes of deterministic link resource planning, reservation and allocation, deterministic link resource constraint-based routing and admission control. A given Traffic Trunk belongs to the same DT on all links. The scheduling type of the deterministic link depends on the classification of the queuing solutions. Many variations and extensions of queuing mechanisms have been proposed to guarantee the deterministic latency in DetNet such as ECQF [IEEE 802.1Qdv], Multi- CQF [I-D.dang-queuing-with-multiple-cyclic-buffers], TCQF [I-D.eckert-detnet-tcqf], CSQF [I-D.chen-detnet-sr-based-bounded-latency], TQF [I-D.peng-detnet-packet-timeslot-mechanism], C-SCORE [I-D.joung-detnet-stateless-fair-queuing], Xiong & Zhu Expires 29 December 2024 [Page 4] Internet-Draft IGP Extensions for Deterministic Link June 2024 EDF[I-D.peng-detnet-deadline-based-forwarding], gLBF [I-D.eckert-detnet-glbf] and so on. [I-D.ietf-detnet-dataplane-taxonomy] has described the classification criteria of the solutions. [I-D.xiong-lsr-time-resource] has proposed the Time-based Resources Container (TRC) to indicate the capabilities with time-based resources. It can be used for deterministic link to reserve the corresponding scheduling resources such as queuing, buffer and bandwidth to guarantee the deterministic capability. For example, three deterministic links with guaranteed jitter are supported between the Node A and Node B as following shown. * deterministic link 1, DT=1 (Jitter Guarantee, Link-scheduling- type=CSQF), bandwidth=20Mbit/s, jitter=10us. * deterministic link 2, DT=2 (Jitter Guarantee, Link-scheduling- type=TCQF), bandwidth=30Mbit/s, jitter=20us. * deterministic link 3, DT=3 (Jitter Guarantee, Link-scheduling- type=TQF), bandwidth=40Mbit/s, jitter=30us. 4. ISIS Extensions of Deterministic Link This document defines new IS-IS TE sub-TLVs to distribute the deterministic link attributes at TE link and it can be announced in TLVs 22, 23, 141, 222, and 223" registry. 4.1. Deterministic Link Sub-TLV A new IS-IS Deterministic Link Sub-TLV is defined and the format is as 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | DT | Link Scheduling Type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Sub-sub-TLV ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Xiong & Zhu Expires 29 December 2024 [Page 5] Internet-Draft IGP Extensions for Deterministic Link June 2024 Figure 2: Deterministic Link Sub-TLV where: * Type: Set to TBD1. * Length: Contains the total length of the sub-TLV in octets. The Length MUST be at least 8 and MUST be a multiple of 4. * DT: the value of DT to indicates the set of Traffic Trunks crossing the deterministic link that is governed by a specific set of bounded latency constraints. * Link Scheduling Type: indicates the type of the queuing or scheduling mechanisms on this deterministic link. * Sub-sub-TLV: indicates the optional sub-sub-TLV carried in this sub-TLV. 4.1.1. Deterministic Link Maximum Reservable Bandwidth Sub-sub-TLV A new IS-IS Deterministic Link Maximum Reservable Bandwidth Sub-sub- TLV is defined and the format is as 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Maximum Reservable Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Deterministic Link Maximum Reserved Bandwidth sub-sub-TLV where: * Type: Set to TBD2. * Length: Contains the total length of the sub-sub-TLV in octets. The Length MUST be at least 8 and MUST be a multiple of 4. * Maximum Reservable Bandwidth: indicates the maximum bandwidth which can be reserved for this deterministic link. Xiong & Zhu Expires 29 December 2024 [Page 6] Internet-Draft IGP Extensions for Deterministic Link June 2024 4.1.2. Deterministic Link Available Bandwidth Sub-sub-TLV A new IS-IS Deterministic Link Available Bandwidth Sub-sub-TLV is defined and the format is as 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Available Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Deterministic Link Available Bandwidth sub-sub-TLV where: * Type: Set to TBD3. * Length: Contains the total length of the sub-sub-TLV in octets. The Length MUST be at least 8 and MUST be a multiple of 4. * Available Bandwidth: indicates the available bandwidth of this deterministic link. 4.1.3. Deterministic Link Delay Sub-sub-TLV A new IS-IS Deterministic Link Delay Sub-sub-TLV is defined and the format is as 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 | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |A| Reserved | Maximum Deterministic Link Delay | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Minimum Deterministic Link Delay | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | Maximum Deterministic Link Delay Variation | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Xiong & Zhu Expires 29 December 2024 [Page 7] Internet-Draft IGP Extensions for Deterministic Link June 2024 Figure 5: Deterministic Link Delay sub-sub-TLV where: * Type: Set to TBD4. * Length: Contains the total length of the sub-sub-TLV in octets. The Length MUST be at least 8 and MUST be a multiple of 4. * A: The A bit represents the Anomalous (A) bit. The A bit is set when the measured value of this parameter exceeds its configured maximum threshold. * Maximum Deterministic Link Delay: indicates the maximum deterministic link delay value (in microseconds) over a configurable interval, encoded as an integer value. * Minimum Deterministic Link Delay: indicates the minimum deterministic link delay value (in microseconds) over a configurable interval, encoded as an integer value. * Maximum Deterministic Link Delay Variation: indicates the maximum deterministic link delay variation value over a configurable interval in microseconds, encoded as an integer value. 5. OSPF Extensions of Deterministic Links TBA 6. Security Considerations Security considerations for DetNet are covered in the DetNet Architecture [RFC8655] and DetNet controller plane [I-D.ietf-detnet-controller-plane-framework] and DetNet security considerations [RFC9055]. The security considerations specified in [RFC5304] are also applicable to the IGP procedures defined in this document. 7. IANA Considerations IANA is requested to register the following sub-TLVs in the "Sub-TLVs for TLVs 22, 23, 141, 222,and 223" registry: Xiong & Zhu Expires 29 December 2024 [Page 8] Internet-Draft IGP Extensions for Deterministic Link June 2024 Type Description ------------------------------------ TBD1 Deterministic Link Sub-TLV TBD2 Deterministic Link Maximum Reservable Bandwidth Sub-sub-TLV TBD3 Deterministic Link Available Bandwidth Sub-sub-TLV TBD4 Deterministic Link Delay Sub-sub-TLV 8. Acknowledgements The authors would like to acknowledge Aihua Liu, Bin Tan for their thorough review and very helpful comments. 9. References 9.1. Normative References [I-D.chen-detnet-sr-based-bounded-latency] Chen, M., Geng, X., Li, Z., Joung, J., and J. Ryoo, "Segment Routing (SR) Based Bounded Latency", Work in Progress, Internet-Draft, draft-chen-detnet-sr-based- bounded-latency-03, 7 July 2023, . [I-D.dang-queuing-with-multiple-cyclic-buffers] Liu, B. and J. Dang, "A Queuing Mechanism with Multiple Cyclic Buffers", Work in Progress, Internet-Draft, draft- dang-queuing-with-multiple-cyclic-buffers-00, 22 February 2021, . [I-D.eckert-detnet-glbf] Eckert, T. T., Clemm, A., Bryant, S., and S. Hommes, "Deterministic Networking (DetNet) Data Plane - guaranteed Latency Based Forwarding (gLBF) for bounded latency with low jitter and asynchronous forwarding in Deterministic Networks", Work in Progress, Internet-Draft, draft-eckert- detnet-glbf-02, 5 January 2024, . Xiong & Zhu Expires 29 December 2024 [Page 9] Internet-Draft IGP Extensions for Deterministic Link June 2024 [I-D.eckert-detnet-tcqf] Eckert, T. T., Li, Y., Bryant, S., Malis, A. G., Ryoo, J., Liu, P., Li, G., Ren, S., and F. Yang, "Deterministic Networking (DetNet) Data Plane - Tagged Cyclic Queuing and Forwarding (TCQF) for bounded latency with low jitter in large scale DetNets", Work in Progress, Internet-Draft, draft-eckert-detnet-tcqf-05, 5 January 2024, . [I-D.ietf-detnet-controller-plane-framework] Malis, A. G., Geng, X., Chen, M., Qin, F., Varga, B., and C. J. Bernardos, "Deterministic Networking (DetNet) Controller Plane Framework", Work in Progress, Internet- Draft, draft-ietf-detnet-controller-plane-framework-06, 27 May 2024, . [I-D.ietf-detnet-dataplane-taxonomy] Joung, J., Geng, X., Peng, S., and T. T. Eckert, "Dataplane Enhancement Taxonomy", Work in Progress, Internet-Draft, draft-ietf-detnet-dataplane-taxonomy-00, 24 May 2024, . [I-D.ietf-detnet-scaling-requirements] Liu, P., Li, Y., Eckert, T. T., Xiong, Q., Ryoo, J., zhushiyin, and X. Geng, "Requirements for Scaling Deterministic Networks", Work in Progress, Internet-Draft, draft-ietf-detnet-scaling-requirements-06, 22 May 2024, . [I-D.joung-detnet-stateless-fair-queuing] Joung, J., Ryoo, J., Cheung, T., Li, Y., and P. Liu, "Latency Guarantee with Stateless Fair Queuing", Work in Progress, Internet-Draft, draft-joung-detnet-stateless- fair-queuing-02, 29 February 2024, . [I-D.peng-detnet-deadline-based-forwarding] Peng, S., Du, Z., Basu, K., cheng, Yang, D., and C. Liu, "Deadline Based Deterministic Forwarding", Work in Progress, Internet-Draft, draft-peng-detnet-deadline- based-forwarding-10, 20 June 2024, . Xiong & Zhu Expires 29 December 2024 [Page 10] Internet-Draft IGP Extensions for Deterministic Link June 2024 [I-D.peng-detnet-packet-timeslot-mechanism] Peng, S., Liu, P., Basu, K., Liu, A., Yang, D., and G. Peng, "Timeslot Queueing and Forwarding Mechanism", Work in Progress, Internet-Draft, draft-peng-detnet-packet- timeslot-mechanism-07, 20 June 2024, . [I-D.xiong-lsr-time-resource] Xiong, Q. and X. Zhu, "IGP Extensions for Time-based Resource", Work in Progress, Internet-Draft, draft-xiong- lsr-time-resource-00, 27 June 2024, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic Authentication", RFC 5304, DOI 10.17487/RFC5304, October 2008, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas, "Deterministic Networking Architecture", RFC 8655, DOI 10.17487/RFC8655, October 2019, . [RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., and J. Hardwick, "Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing", RFC 8664, DOI 10.17487/RFC8664, December 2019, . [RFC9055] Grossman, E., Ed., Mizrahi, T., and A. Hacker, "Deterministic Networking (DetNet) Security Considerations", RFC 9055, DOI 10.17487/RFC9055, June 2021, . [RFC9320] Finn, N., Le Boudec, J.-Y., Mohammadpour, E., Zhang, J., and B. Varga, "Deterministic Networking (DetNet) Bounded Latency", RFC 9320, DOI 10.17487/RFC9320, November 2022, . Xiong & Zhu Expires 29 December 2024 [Page 11] Internet-Draft IGP Extensions for Deterministic Link June 2024 Authors' Addresses Quan Xiong ZTE Corporation China Email: xiong.quan@zte.com.cn Xiangyang Zhu ZTE Corporation China Email: zhu.xiangyang@zte.com.cn Xiong & Zhu Expires 29 December 2024 [Page 12]