Internet DRAFT - draft-geng-detnet-dataplane-enchancment-encap
draft-geng-detnet-dataplane-enchancment-encap
Network Working Group X. Geng
Internet-Draft Huawei
Intended status: Standards Track 13 March 2023
Expires: 14 September 2023
DetNet Enhancement Data Plane Encapsulation：Gap Analysis and Solution
draft-geng-detnet-dataplane-enchancment-encap-01
Abstract
This document introduces the Gap Analysis and Solution for DetNet
Enhancement Data Plane Encapsulation in order to deploy scalable
DetNet Data Plane solution in layer 3 network.
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].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 14 September 2023.
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Copyright (c) 2023 IETF Trust and the persons identified as the
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. DetNet Data Plane Enhanement Gap Analysis . . . . . . . . . . 2
3. DetNet Data Plane Enhanement Encapsultion . . . . . . . . . . 4
3.1. IPv4/IPv6 Header . . . . . . . . . . . . . . . . . . . . 4
3.2. MPLS . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.3. IPv6 Extension Header . . . . . . . . . . . . . . . . . . 4
3.4. SR MPLS/ SRv6 . . . . . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. References . . . . . . . . . . . . . . . . . . . . . . . 6
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
[I-D.ietf-detnet-scaling-requirements] has introduced the evaluation
items for different mechanism and provide guidance for judging
whether a cerntain mechasnim could satisfy DetNet Enhancement
requirement in order to deploy in layer 3 network. This document
introduces the Gap Analysis and Solution for DetNet Enhancement Data
Plane Encapsulation.
2. DetNet Data Plane Enhanement Gap Analysis
DetNet data plane enhancement includes 2 parts: Queuing, Shaping,
Scheduling, Preemption and encapsulation.
* Queuing, Shaping, Scheduling, and Preemption
As defined in [RFC8655] , queuing and transmission-selection
algorithms allow DetNet mechanisms to compute the latency
contribution of each DetNet node to the end-to-end latency, to
compute the amount of buffer space required in each DetNet node for
each incremental DetNet flow. So it provides the base of bounded
latency.
IEEE also provide mechansim that could be reused in DetNet Data Plane
Enhancment:
A credit-based shaper [IEEE802.1Qav] (incorporated to
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[IEEE802.1Q]).
Time-gated queues governed by a rotating time schedule based on
synchronized time [IEEE802.1Qbv] (incorporated to [IEEE802.1Q]).
Synchronized double (or triple) buffers driven by synchronized
time ticks. [IEEE802.1Qch] (incorporated to [IEEE802.1Q]).
Preemption of an Ethernet packet in transmission by a packet with
a more stringent latency requirement, followed by the resumption
of the preempted packet [IEEE802.1Qbu] (incorporated to
[IEEE802.1Q]) [IEEE802.3br] (incorporated to [IEEE802.3]).
New mechanisms based on the hardware capability of existing network
device are also considered.
* Encapsulation
Different queuing, shaping, scheduling mechanisms request different
encapsulation in layer 3.
Priority:
Some of the queuing mechanism, e.g., QoS, L4S, preemption, DetNet
traffic is handled differently based on the priority for bounded
latency. The existing encapsulation, such as DSCP or ECN in IP
header, could be used to differenciate the prioriy.
Flow/Flow Aggregation Identification
Some of the queuing mechanism, e.g., Qbv, VPN+, DetNet traffic is
handled differently based on the flow identification or flow
aggregation identification(network slice)for bounded latency. The
existing encapsulation, such as DetNet Stream Label in MPLS or 5
tupes in IP , could be used to differenciate the flow or flow
aggregation.
Time Information
Some of the queuing mechanism, e.g., Qbv, VPN+, DetNet traffic is
handled differently based on the flow identification or flow
aggregation identification(network slice)for bounded latency. The
existing encapsulation, such as DetNet Stream Label in MPLS or 5
tupes in IP , could be used to differenciate the flow or flow
aggregation.
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3. DetNet Data Plane Enhanement Encapsultion
This section defined DetNet Data Plane Enhanement Encapsultion based
on the analysis result of section 2.
3.1. IPv4/IPv6 Header
New DSCP value or new DSCP meaning could be defined for presenting
time information, such as
3.2. MPLS
New EXP value of MPLS Lable could be introduced to convey time
information.
3.3. IPv6 Extension Header
The following option could be defined in IPv6 extension header to
convey time information:
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Context Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Time Information ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Option Type: 8-bit identifier of the type of option. The type of VTN
option is to be assigned by IANA.
Opt Data Len: 8-bit unsigned integer indicates the length of the
option Data field of this option, in octets.
Flags: 8-bit flags field.
Time Information: time slot ID, cycel ID, timestamp, ect.
3.4. SR MPLS/ SRv6
Time Aware SID could be introduced to convey time information, such
as[I-D.chen-detnet-sr-based-bounded-latency] and
[I-D.geng-srv6-based-bounded-latency].
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4. IANA Considerations
This document makes no request of IANA.
Note to RFC Editor: this section may be removed on publication as an
RFC.
5. Security Considerations
This document does not introduce any new security considerations.
6. Acknowledgements
7. References
7.1. Normative References
[I-D.chen-detnet-sr-based-bounded-latency]
Chen, M., Geng, X., and Z. Li, "Segment Routing (SR) Based
Bounded Latency", Work in Progress, Internet-Draft, draft-
chen-detnet-sr-based-bounded-latency-02, 13 March 2023,
<https://datatracker.ietf.org/api/v1/doc/document/draft-
chen-detnet-sr-based-bounded-latency/>.
[I-D.geng-srv6-based-bounded-latency]
Geng, X. and M. Chen, "SRv6 Based Bounded Latency", Work
in Progress, Internet-Draft, draft-geng-srv6-based-
bounded-latency-00, 7 May 2019,
<https://datatracker.ietf.org/doc/html/draft-geng-srv6-
based-bounded-latency-00>.
[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-01, 1 March 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-detnet-
scaling-requirements-01>.
[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>.
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[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>.
7.2. References
Author's Address
Xuesong Geng
Huawei
Email: gengxuesong@huawei.com
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