Delay Options
draft-peng-6man-delay-options-00
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Author | Shaofu Peng | ||
| Last updated | 2024-01-18 | ||
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| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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draft-peng-6man-delay-options-00
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
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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
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Please review these documents carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
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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.
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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:
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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
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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
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[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,
<https://datatracker.ietf.org/doc/html/draft-eckert-
detnet-glbf-02>.
[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,
<https://datatracker.ietf.org/doc/html/draft-peng-detnet-
deadline-based-forwarding-08>.
[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, <https://datatracker.ietf.org/api/v1/doc/document/
draft-peng-detnet-policing-jitter-control/>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8655] Finn, N., Thubert, P., Varga, B., and J. Farkas,
"Deterministic Networking Architecture", RFC 8655,
DOI 10.17487/RFC8655, October 2019,
<https://www.rfc-editor.org/info/rfc8655>.
9.2. Informative References
[ATS_Damper]
"Constant Delay Switching: Asynchronous Traffic Shaping
with Jitter Control", 2022,
<https://ieeexplore.ieee.org/document/9829777>.
Author's Address
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Shaofu Peng
ZTE Corporation
China
Email: peng.shaofu@zte.com.cn
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