LSR Q. Xiong Internet-Draft X. Qian Intended status: Standards Track ZTE Corporation Expires: 25 April 2024 23 October 2023 IGP Extensions for DetNet Deterministic Links draft-xiong-lsr-detnet-deterministic-links-00 Abstract This document proposes the deterministic links to provide a one- dimensional deterministic metric to guarantee 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 25 April 2024. Copyright Notice Copyright (c) 2023 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 & Qian Expires 25 April 2024 [Page 1] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Deterministic Links . . . . . . . . . . . . . . . . . . . . . 3 3.1. Deterministic Links Model . . . . . . . . . . . . . . . . 3 3.2. Classfication of deterministic Links . . . . . . . . . . 4 3.3. Deterministic Links Resources . . . . . . . . . . . . . . 5 4. ISIS Extensions of Deterministic Links . . . . . . . . . . . 5 4.1. Deterministic Link Sub-TLV . . . . . . . . . . . . . . . 5 4.1.1. Deterministic Link Maximum Reservble 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 . . . . . . . . . . . . . . . . . . . . . . . 10 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. [I-D.xiong-detnet-large-scale-enhancements] has proposed the packet treatment which should support new functions such as queuing mechanisms to ensure the deterministic latency. As per [I-D.ietf-detnet-controller-plane-framework], network nodes collects topology information and DetNet capabilities through IGP. The computing method of end-to-end delay bounds is defined in [RFC9320]. It is the sum of the six delays in DetNet bounded latency model. It is the sum of non-queuing delay bound and queuing delay bound in DetNet bounded latency model. 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 a non-determinisitc link and a link with a queuing mechanism that can provide deterministic delay is called a deterministic link. The delay of a a deterministic link is consist Xiong & Qian Expires 25 April 2024 [Page 2] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 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 links to provide a one- dimensional deterministic metric to guarantee 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 Links This document proposes the deterministic links to provide a one- dimensional deterministic metric to guarantee the deterministic forwarding capabilities at different levels. The deterministic links can shield the differences from underlying forwarding and queuing mechanisms. 3.1. Deterministic Links 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 * Deterministic Node Delay = Processing delay Xiong & Qian Expires 25 April 2024 [Page 3] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 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 Links Model 3.2. Classfication 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. 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. 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, queuing type=CSQF), bandwidth=20Mbit/s, jitter=10us. * deterministic link 2, DT=2 (Jitter Guarantee, queuing type=TCQF), bandwidth=30Mbit/s, jitter=20us. * deterministic link 3, DT=3 (Jitter Guarantee, queuing type=TQF), bandwidth=40Mbit/s, jitter=30us. Xiong & Qian Expires 25 April 2024 [Page 4] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 3.3. Deterministic Links Resources The traditional resource reservation method only considers the bandwidth availability of the BE (Best Effort) flow, which means that the reserved bandwidth meets the peak information rate (PIR) of the business flow at the macro level. As per [I-D.ietf-detnet-scaling-requirements], the enhanced DetNet need to support multiple queuing mechanisms to provide deterministic latency. For such scheduling mechanisms, even the bandwidth resources meet the transmission requirements at the macro level, there may not be enough resources in a specific timeslot, cycle or authorization time zone, so bounded delay and jitter cannot be guaranteed. So it is required to provide provisioning of fine-grained reservation for time-based resources. Time-based Resources Container (TRC): the entity which is used for deterministic link to provide the time-based resources with deterministic capabilities by resolving resource conflicts between different levels. The container indicates the maximum transmitting bits per scheduling timeslot and it contains the corresponding scheduling resources reserved to guarantee the capability of deterministic link such as queuing, buffer and bandwidth. 4. ISIS Extensions of Deterministic Links This document defines new IS-IS TE sub-TLVs to distribute the deterministic links 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 & Qian Expires 25 April 2024 [Page 5] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 Figure 2: Deterministic Link Sub-TLV where: * Type: Set to TBD1. * Length: Contains the total length of the subobject 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 linke 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 Reservble Bandwidth Sub-sub-TLV A new IS-IS Deterministic Link Maximum Reservble 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 Reserved Bandwidth | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Deterministic Link Maximum Reservble Bandwidth sub-sub-TLV where: * Type: Set to TBD2. * Length: Contains the total length of the subobject in octets. The Length MUST be at least 8 and MUST be a multiple of 4. * Maximum Reserved Bandwidth: indicates the maximum reservble bandwidth for this deterministic link. Xiong & Qian Expires 25 April 2024 [Page 6] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 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 subobject 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 & Qian Expires 25 April 2024 [Page 7] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 Figure 5: Deterministic Link Delay sub-sub-TLV where: * Type: Set to TBD4. * Length: Contains the total length of the subobject 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 TBA 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: Type Description ------------------------------------ TBD1 Deterministic Link Sub-TLV TBD2 Deterministic Link Maximum Reservble Bandwidth Sub-sub-TLV TBD3 Deterministic Link Available Bandwidth Sub-sub-TLV TBD4 Deterministic Link Delay Sub-sub-TLV Xiong & Qian Expires 25 April 2024 [Page 8] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 8. Acknowledgements TBA 9. References 9.1. Normative References [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-05, 26 September 2023, . [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-04, 18 October 2023, . [I-D.xiong-detnet-large-scale-enhancements] Xiong, Q., Du, Z., Zhao, J., and D. Yang, "Enhanced DetNet Data Plane (EDP) Framework for Scaling Deterministic Networks", Work in Progress, Internet-Draft, draft-xiong- detnet-large-scale-enhancements-03, 10 July 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . Xiong & Qian Expires 25 April 2024 [Page 9] Internet-Draft IGP Extensions for DetNet Deterministic October 2023 [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, . [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, . Authors' Addresses Quan Xiong ZTE Corporation China Email: xiong.quan@zte.com.cn Xiaocong Qian ZTE Corporation China Email: qian.xiaocong@zte.com.cn Xiong & Qian Expires 25 April 2024 [Page 10]