Network Shaofu. Peng Internet-Draft ZTE Corporation Intended status: Standards Track 18 January 2024 Expires: 21 July 2024 Delay Options draft-peng-6man-delay-options-00 Abstract This document introduces new IPv6 options for HBH or DOH Options header, to carry delay related information for deterministic forwarding. 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 21 July 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. Peng Expires 21 July 2024 [Page 1] Internet-Draft Delay Options January 2024 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 2. Path Latency Deviation Option . . . . . . . . . . . . . . . . 3 3. Endpoint Damping Delay Option . . . . . . . . . . . . . . . . 4 4. Process of Path Latency Deviation Option . . . . . . . . . . 5 5. Process of Endpoint Damping Delay Option . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 7. Security Considerations . . . . . . . . . . . . . . . . . . . 5 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 9.1. Normative References . . . . . . . . . . . . . . . . . . 5 9.2. Informative References . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6 1. Introduction [RFC8655] describes the architecture of deterministic network and defines the QoS goals of deterministic forwarding: Minimum and maximum end-to-end latency from source to destination, timely delivery, and bounded jitter (packet delay variation); packet loss ratio under various assumptions as to the operational states of the nodes and links; an upper bound on out-of-order packet delivery. In order to achieve these goals, deterministic networks use resource reservation, explicit routing, service protection and other means. In general, a deterministic path is a strictly explicit path calculated by a centralized controller, and resources are reserved on the nodes along the path. To provide deterministic forwarding service, the scheduling mechanisms applied in the network generally require application flows to comply with predefine constraints, such as a token bucket specification consisting of a "token rate" r and a "bucket size" b. This can be achieved by configuring regulators with parameter (r, b) and states per flow on each node, however, the cost is too high. Another more feasible way is to carry the states in the packet, and the scheduling mechanism automatically regulate and sorts the packet based on the states read from the packet. Peng Expires 21 July 2024 [Page 2] Internet-Draft Delay Options January 2024 There are some common states that are used by multiple scheduling mechanisms. For example, the latency deviation (E) defined in [I-D.peng-detnet-deadline-based-forwarding], and the damping delay defind in [ATS_Damper] or [I-D.eckert-detnet-glbf], are actually the same thing and can be considered as the latency compensation used for the forwarded path. Another example is that the endpoint damping delay defined in [I-D.peng-detnet-policing-jitter-control] can be combined with any on-time scheduling mechanisms to further avoid jitter caused by policing delay. This document introduces new IPv6 options for HBH or DOH Options header, to carry common scheduling parameters for deterministic forwarding. Note that the motivation of the common scheduling parameters defined in this document is to be shared and used by multiple scheduling mechanisms, rather than a container that includes some different parameters. 1.1. 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. 2. Path Latency Deviation Option The path latency deviation is used to characterize the deviation between the delay budget (such as a planned residence time or estimated worst-case delay) and the actual delay of a packet at each hop. Each hop along the path can use this information to shape or sort arrived packets, to ensure that the flow conforms to predefined constraints. Examples include the latency deviation (E) defined in [I-D.peng-detnet-deadline-based-forwarding] and damping delay defined in [ATS_Damper] or [I-D.eckert-detnet-glbf]. Strictly speaking, the path latency deviation should be a cumulative value, that is, it accumulates the latency deviation of all upstream nodes. If the scheduling mechanism used in the network can ensure that the path latency deviation is cleared and reset at each hop, then this cumulative value actually only includes the latency deviation generated by a single hop and updated again on the next hop. The scope of use of the path latency deviation is the forwarded path. It is recommoned to be included in HBH Options Header. The path latency deviation option has the following format: Peng Expires 21 July 2024 [Page 3] Internet-Draft Delay Options January 2024 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Type | Opt Data Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Path Latency Deviation | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: Path Latency Deviation Option Option Type: 8-bit identifier of the type of option. Value TBD by IANA; the highest-order 3 bits of thie field is 001 to skip over this option and continue processing the header if the processing IPv6 node does not recognize the Option Type and to permit the Option Data to be changed en route to the packet's final destination. Opt Data Len: 8-bit unsigned integer. Length of the Option Data field of this option, in octets. It is set to 4. Path Latency Deviation: 32-bit signed integer, represents the the deviation between delay budget and actual delay on each hop. 3. Endpoint Damping Delay Option The endpoint damping delay is used to characterize the necessary holding time of the packet on the endpoint of the path, to avoid jitter caused by policing delay. Please refer to [I-D.peng-detnet-policing-jitter-control] for more details. The scope of use of the endpoint damping delay is the endpoint. It is recommoned to be included in DOH Options Header. Note that in the multi-domain case, each domain exit may also need to be aware of endpoint damping delay to control jitter. If so, it is recommended to place DOH before the corresponding Routing Header for each domain. The endpoint damping delay option has the following format: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Type | Opt Data Len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Endpoint Damping Delay | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Endpoint Damping Delay Option Peng Expires 21 July 2024 [Page 4] Internet-Draft Delay Options January 2024 Option Type: 8-bit identifier of the type of option. Value TBD by IANA; the highest-order 3 bits of thie field is 001 to skip over this option and continue processing the header if the processing IPv6 node does not recognize the Option Type and to permit the Option Data to be changed en route to the packet's final destination. Opt Data Len: 8-bit unsigned integer. Length of the Option Data field of this option, in octets. It is set to 4. Endpoint Damping Delay: 32-bit signed integer, represents the the holding time imposed on the endpoint before the packet is delivered to the application destination (or next domain). 4. Process of Path Latency Deviation Option TBD. 5. Process of Endpoint Damping Delay Option TBD. 6. IANA Considerations This document updates the "Destination Options and Hop-by-Hop Options" under the "Internet Protocol Version 6 (IPv6) Parameters" registry: +---------+-----+-----+------+-----------------------+-------------+ |Hex Value| act | chg | rest | Description | Reference | +---------+-----+-----+------+-----------------------+-------------+ | TBD1 | 00 | 1 | 00000| Path Latency Deviation|This document| +---------+-----+-----+------+-----------------------+-------------+ | TBD2 | 00 | 1 | 00000| Endpoint Damping Delay|This document| +---------+-----+-----+------+-----------------------+-------------+ 7. Security Considerations TBD 8. Acknowledgements TBD 9. References 9.1. Normative References Peng Expires 21 July 2024 [Page 5] Internet-Draft Delay Options January 2024 [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, . [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-08, 14 December 2023, . [I-D.peng-detnet-policing-jitter-control] Peng, S., Liu, P., and K. Basu, "Policing Caused Jitter Control Mechanism", Work in Progress, Internet-Draft, draft-peng-detnet-policing-jitter-control-00, 18 January 2024, . [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, . 9.2. Informative References [ATS_Damper] "Constant Delay Switching: Asynchronous Traffic Shaping with Jitter Control", 2022, . Author's Address Peng Expires 21 July 2024 [Page 6] Internet-Draft Delay Options January 2024 Shaofu Peng ZTE Corporation China Email: peng.shaofu@zte.com.cn Peng Expires 21 July 2024 [Page 7]