Internet-Draft IGP Extensions for Time-based Resource June 2024
Xiong & Zhu Expires 29 December 2024 [Page]
Workgroup:
LSR
Internet-Draft:
draft-xiong-lsr-time-resource-00
Published:
Intended Status:
Standards Track
Expires:
Authors:
Q. Xiong
ZTE Corporation
X. Zhu
ZTE Corporation

IGP Extensions for Time-based Resource

Abstract

This document proposes the time-based resources and the distribution by IGP extensions for traffic engineering in control plane to simplify resource management and scheduling in certain networks requiring the latency guarantees.

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.

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). DetNet uses resource allocation mechanism of Traffic Engineering (TE) technology to ensure a certain level of QoS, such as eliminating the contention loss and reducing jitter.

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 flow at the macro level. Bandwidth is generally used to meet the average rate, representing the maximum amount of bits within one second. But in large-scale network, there are problems such as large amount of dynamic concurrent traffic, complex topology, and long-distance propagation latency. Even the bandwidth resources meet the transmission requirements at the macro level, it may not guarantee the bounded latency due the bursts of massive traffic flows.

As per [I-D.ietf-detnet-scaling-requirements], the enhanced DetNet needs to support multiple time-based queuing mechanisms to provide deterministic latency. [I-D.ietf-detnet-dataplane-taxonomy] has discussed the classification criteria of many variations and extensions of queuing mechanisms 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], EDF[I-D.peng-detnet-deadline-based-forwarding], gLBF [I-D.eckert-detnet-glbf] and so on.

As per [I-D.ietf-detnet-dataplane-taxonomy], the enhancement solutions can be a combination of multiple data plane functional entities, such as regulators/shapers, queues, and schedulers. It requires enough bandwidth resources in a specific timeslot, cycle or authorization time zone to guarantee the bounded delay and jitter. So it is required to provide provisioning of fine-grained reservation for time-based resources which is a combination of bandwidth, buffer and time-based regulators/shapers, queues, and schedulers.

This document proposes the time-based resources and the distribution by IGP extensions for traffic engineering in control plane to simplify resource management and scheduling in certain networks requiring the latency guarantees.

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].

1.2. Terminology

The terminology is defined as [RFC8655] and [RFC9320].

2. Time-based Resource Container

The queuing and scheduling mechanism needs to combine corresponding buffer and bandwidth requirements to ensure the transmission delay and jitter of deterministic flows. This document lists the bandwidth requirements for different queuing mechanisms as following.

  • For the ATS/CBS/C-SCORE mechanism, different traffic classes (such as class A, class B) can allocate initial burst and bandwidth, and then obtain the upper bound of each hop delay for each traffic class based on the "rate and delay" service curve.
  • For the CQF/CSQF/TCQF mechanism, different cycle levels can allocate initial bandwidth resource, and the upper bound of each hop delay at each cycle level is related to the cycle length.
  • For the EDF mechanism, different delay levels can allocate initial burst resources and bandwidth resource, satisfying schedulability conditions. Each delay level determines the upper bound of delay per hop.
  • For the TQF mechanism, it has an initial burst resource for each slot number during the scheduling cycle, which does not exceed the length of the slot multiplied by the link bandwidth. The upper bound of each hop delay depends on the offset between the incoming slot and the reserved outgoing slot.

It is required to provide provisioning of fine-grained reservation for time-based resources which is a combination of bandwidth buffer and time-based regulators/shapers, queues, and schedulers. This can be approached with a tight control of the deterministic resources to maintain the amount of traffic within a budgeted volume of data per unit of time that fits the deterministic capabilities of the underlying network, and the use of time-based resources (bandwidth and buffers) per circuit, and by shaping and scheduling the packets at every hop.

This document defines the Time-based Resources Container (TRC) which is the virtual entity being used for link or node to provide the time-based resources with deterministic capabilities by resolving resource conflicts between different levels. The time-based resources container indicates the transmit data size per unit of time. The container indicates the transmitting bits per scheduling timeslot and contains the corresponding scheduling resources reserved to guarantee the capability of deterministic link and it may include queuing, buffer or bandwidth.

3. ISIS Extensions of Time-based Resources

3.1. Time-based Resources Sub-TLV


   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              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           MaxReservableTimeResourcesBandwidth               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Time Unit Length                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Time Unit Number                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ~                        Sub-sub-TLV                          ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 1: Time-based Resources 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.
  • MaxReservableTimeResourcesBandwidth: indicates the maximum bandwidth which can be reserved for this time-based resources container.
  • Time Unit Length: indicates the length of the time units in the time-based resources container.
  • Time Unit Number: indicates the number of the time units in the time-based resources container.

A new IS-IS Time Unit 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              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Time Unit ID            |          Reserved             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                          AvailbleTimeUnitSize               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Figure 2: Time Unit 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.
  • Time Unit ID: indicates the identifier of the time unit.
  • AvailbleTimeUnitSize: indicates availble size of this time unit which can be reserved.

4. OSPF Extensions of Time-based Resources

TBA

5. 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.

6. 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    Time-based Resources Sub-TLV
    TBD2    Time Unit Sub-sub-TLV

7. Acknowledgements

The authors would like to acknowledge Aihua Liu, Bin Tan for the thorough review and very helpful comments.

8. References

8.1. 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, , <https://datatracker.ietf.org/doc/html/draft-chen-detnet-sr-based-bounded-latency-03>.
[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, , <https://datatracker.ietf.org/doc/html/draft-dang-queuing-with-multiple-cyclic-buffers-00>.
[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, , <https://datatracker.ietf.org/doc/html/draft-eckert-detnet-glbf-02>.
[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, , <https://datatracker.ietf.org/doc/html/draft-eckert-detnet-tcqf-05>.
[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, , <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-controller-plane-framework-06>.
[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, , <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-dataplane-taxonomy-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-06, , <https://datatracker.ietf.org/doc/html/draft-ietf-detnet-scaling-requirements-06>.
[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, , <https://datatracker.ietf.org/doc/html/draft-joung-detnet-stateless-fair-queuing-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-10, , <https://datatracker.ietf.org/doc/html/draft-peng-detnet-deadline-based-forwarding-10>.
[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, , <https://datatracker.ietf.org/doc/html/draft-peng-detnet-packet-timeslot-mechanism-07>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC5304]
Li, T. and R. Atkinson, "IS-IS Cryptographic Authentication", RFC 5304, DOI 10.17487/RFC5304, , <https://www.rfc-editor.org/info/rfc5304>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <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, , <https://www.rfc-editor.org/info/rfc8655>.
[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, , <https://www.rfc-editor.org/info/rfc8664>.
[RFC9055]
Grossman, E., Ed., Mizrahi, T., and A. Hacker, "Deterministic Networking (DetNet) Security Considerations", RFC 9055, DOI 10.17487/RFC9055, , <https://www.rfc-editor.org/info/rfc9055>.
[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, , <https://www.rfc-editor.org/info/rfc9320>.

Authors' Addresses

Quan Xiong
ZTE Corporation
China
Xiangyang Zhu
ZTE Corporation
China