SPRING Working Group W. Cheng
Internet-Draft W. Jiang
Intended status: Standards Track China Mobile
Expires: 22 April 2025 R. Chen
ZTE Corporation
C. Lin
New H3C Technologies
G. Zhang
China Mobile
19 October 2024
Resource Guarantee for SRv6 Policies
draft-cheng-spring-srv6-policy-resource-gurantee-04
Abstract
This document defines a new SRv6 Endpoint behavior which can be used
to associate with a set of network resource partition (e.g.
bandwidth, buffer and queue resources ) Programming, called End.NRP.
By using the End.NRP SID to build its segment list , the SRv6 policy
has the capability to program network resources and achieve strict
SLA guarantees.
Status of This Memo
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This Internet-Draft will expire on 22 April 2025.
Copyright Notice
Copyright (c) 2024 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
2. End.NRP Behavior . . . . . . . . . . . . . . . . . . . . . . 3
3. Use Cases for End.NRP behavior . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. Implementation Status . . . . . . . . . . . . . . . . . . . . 6
5.1. ZTE Corp . . . . . . . . . . . . . . . . . . . . . . . . 7
5.2. New H3C Technologies . . . . . . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
7.1. Normative References . . . . . . . . . . . . . . . . . . 8
7.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
The concept of Network Resource Partition is introduced in
[I-D.ietf-teas-ietf-network-slices]. A Network Resource Partition
(NRP) is a set of network resources that are allocated from the
underlay network to carry a specific set of network traffic and meet
the required SLOs and SLEs.
Segment Routing (SR) [RFC8402] leverages the source routing paradigm.
An ingress node steers a packet through an ordered list of
instructions, called "segments". Each one of these instructions
represents a function to be called at a specific location in the
network. A function is locally defined on the node where it is
executed and may range from simply moving forward in the segment list
to any complex user-defined behavior.
SR Policy is an ordered list of segments (i.e. instructions) that
represent a source-routed policy. The packets steered into an SR
Policy have an ordered list of segments associated with that SR
Policy.
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Since the SRv6 Endpoint behavior defined in [RFC8986] are not
associated with a set of network resource partition of the interface
for slices/slice aggregate(e.g.End.X just forwards to an endpoint
with cross-connect to a 'layer-3 adjacency' or L2 bundles).
Therefore, SRv6 policies can't achieve strict SLA guarantees.
[I-D.ietf-spring-resource-aware-segments]extends the SR paradigm by
associating SIDs with network resource attributes. On the basis of
[I-D.ietf-spring-resource-aware-segments], this document defines a
new SRv6 Endpoint behavior which can be used to associate with a set
of network resource partition (e.g. bandwidth, buffer and queue
resources ) Programming, called End.NRP. By using the End.NRP SID to
build its segment list , the SRv6 policy has the capability to
program network resources and achieve strict SLA guarantees.
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.
1.2. Terminology
The following terminology is used in this document:
* NRP: Network Resource Partition
* PSP: Penultimate Segment Pop
* SLA: Service Level Agreement
* SR: Segment Routing
* SRv6:The instantiation of SR on the IPv6 data plane.
* USD: Ultimate Segment Decapsulation
* USP: Ultimate Segment Pop
2. End.NRP Behavior
This section defines a new SRv6 Endpoint behavior which can be used
to associate with a set of snetwork resource partition (e.g.
bandwidth, buffer and queue resources ) Programming, called End.NRP.
The End.NRP is a variant of the End.X behavior defined in [RFC8986].
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Any SID instance of End.NRP behavior is associated with two sets: J1
and J2.
J1: one or more L3 adjacencies or L2 bundles
J2: NRP of J1
When N receives a packet destined to S and S is a local End.NRP SID,
the line S15 from the End processing defined in [RFC8986] is replaced
by the following:
S15. Submit the packet to the IPv6 module for transmission to
the new destination via a member of J1, using the NRP
identified by J2
This End.NRP SID SHOULD support the Penultimate Segment Pop (PSP) of
the SRH, Ultimate Segment Pop (USP) of the SRH, and Ultimate Segment
Decapsulation (USD) flavors defined in [RFC8986] either individually
or in combinations. The SRH processing of the End.NRP behavior with
PSP, USP, and USD is the same as [RFC8986].
This End.NRP SIDs can be allocated either by a centralized network
controller or by the network nodes, and the End.NRP behavior MAY be
announced using IGP or BGP-LS. The detailed protocol extension will
be described in a separate document.
3. Use Cases for End.NRP behavior
This section describes possible procedures for the End.NRP behavior.
A group of End.NRP SIDs SHOULD be allocated for the set of network
resources associated with the SRv6 Policies, so that different
End.NRP SIDs SHOULD be used to steer service traffic into different
set of link resources (e.g. bandwidth, buffer and queue resources) in
packet forwarding.
Below is the possible procedures:
1. The controller get the topology information, calculate the SR
Policy path based on SLA.
2. The controller cooperates with the network nodes to complete
resource reservation and the End.NRP SID allocation along the SR
Policy path.
3. The controller use the End.NRP SID to build the SID list for the
explicit path.
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4. Then the controller inform the headend the resource guaranteed
path by various means including: via BGP
[I-D.ietf-idr-segment-routing-te-policy], configuration or PCEP
[RFC8664] [I-D.ietf-pce-segment-routing-policy-cp].
SRv6 Policy1 from PE1 to PE2
segment list <End.NRP11, End.NRP12, End.NRP13>
SRv6 Policy2 from PE1 to PE2
segment list <End.NRP21, End.NRP22, End.NRP23>
End.NRP12
End.NRP22
* * * * * *
P1-----------P2
*/*|* * * * * * |\ * *
*/* | | \ * *
CE11----- End.NRP11| |End.NRP13 ------ CE12
\ End.NRP21| |End.NRP23 /
\ */ * | | \* * /
PE1 \ | | PE2
/ \ | | / \
/ \ | | / \------ CE2
CE21------ \ | | /
\ | | /
P3------------P4
Figure 1
Figure 1 shows an example for the End.NRP behavior.
As shown in Figure 1, there are two customers with different leased
line requirements from PE1 to PE2:
leased line1 : 1G BandWidth with strict SLA guarantee.
leased line2 : 2G BandWidth with strict SLA guarantee.
Below is the possible procedures:
1. The controller get the topology information, calculate the SRv6
Policy 1 and SRv6 Policy 2 based on SLA.
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2. The controller cooperates with the network nodes to complete
resource reservation and the End.NRP SID allocation along the
SRv6 Policy1 and SRv6 Policy 2. Taking the interface PE1-P1 of
SRv6 node PE1 along the SRv6 Policy 1 as an example, two
different NRPs(e.g. two dedicated queues) are partitioned from
the network resources of the physical link PE1-P1 (GE1/0/0).
* The NRP(Queue1:1G BW)of link PE1- P1 is reserved and
associated with End.NRP11.
* The NRP(Queue2:2G BW)of link PE1- P1 is reserved and
associated with End.NRP21.
3. The controller uses the End.NRP11, End.NRP12, and End.NRP13 to
build the SID list for the SRv6 Policy1 and use the End.NRP21,
End.NRP22, and End.NRP23 to build the SID list for the SRv6
Policy 2.
4. Then the controller inform the headend the segment list of SRv6
Policy 1 and the segment list of SRv6 Policy 2 by various means
including: via BGP [I-D.ietf-idr-segment-routing-te-policy],
configuration or PCEP [RFC8664]
[I-D.ietf-pce-segment-routing-policy-cp].
The traffic from customer1 and customer2 will be forwarded to PE2
through the NRPs previously reserved for each hop link on the path of
SRv6 Policy1 and SRv6 Policy2 respectively, thus Customer 1 and
Customer 2 are provided with end-to-end 1G bandwidth resources and 2G
bandwidth resources respectively, and private line services are
guaranteed by strict SLAs.
4. Security Considerations
The security requirements and mechanisms described in [RFC8402],
[RFC8754] and [RFC8986] also apply to this document.
This document introduces a new SRv6 Endpoint behavior for
implementation on the nodes support network resource partition in the
network. As such, this document does not introduce any new security
considerations.
5. Implementation Status
[Note to the RFC Editor - remove this section before publication, as
well as remove the reference to [RFC7942]].
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This section records the status of known implementations of the
protocol defined by this specification at the time of posting of this
Internet-Draft, and is based on a proposal described in [RFC7942].
The description of implementations in this section is intended to
assist the IETF in its decision processes in progressing drafts to
RFCs. Please note that the listing of any individual implementation
here does not imply endorsement by the IETF. Furthermore, no effort
has been spent to verify the information presented here that was
supplied by IETF contributors. This is not intended as, and must not
be construed to be, a catalog of available implementations or their
features. Readers are advised to note that other implementations may
exist.
According to [RFC7942], "this will allow reviewers and working groups
to assign due consideration to documents that have the benefit of
running code, which may serve as evidence of valuable experimentation
and feedback that have made the implemented protocols more mature.
It is up to the individual working groups to use this information as
they see fit".
5.1. ZTE Corp
* Organization: ZTE Corporation.
* Implementation: ZTE's M6000 Series Routers implementation of
END.NRP [ZTE-IMP].
* Description: The feature of SRv6 END.NRP has been implemented in
ZTE M6000 series routers and follows the definition and mechanism
as defined in section 2 and Section 3 including all the "MUST" and
"SHOULD" clauses.
* Maturity Level: Beta
* Coverage: ALL, section 2 and use case section 3.
* Version: Draft-02
* Licensing: N/A
* Implementation experience: Nothing specific.
* Contact: zhu.xiaolong@zte.com.cn
* Last updated: October 21, 2023
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5.2. New H3C Technologies
* Organization: New H3C Technologies.
* Implementation: H3C CR16000, CR19000 series routers
implementation.
* Description: Section 2 and Section 3 including all the "MUST" and
"SHOULD" clauses have been implemented in above mentioned New H3C
Products for testing.
* Maturity Level: Beta
* Coverage: ALL, section 2 and use case section 3.
* Version: Draft-02
* Licensing: N/A
* Implementation experience: Nothing specific.
* Contact: linchangwang.04414@h3c.com
* Last updated: October 21, 2023
6. IANA Considerations
The document defines a new SRv6 Endpoint behavior called End.NRP.
This I-D requests the IANA to allocate, within the "SRv6 Endpoint
Behaviors" sub-registry belonging to the top-level "Segment-routing
with IPv6 dataplane (SRv6) Parameters" registry, the following
allocations:
Value Endpoint Behavior Reference
---------------------------------------------------------------
TBD1 End.NRP [This.ID]
7. References
7.1. Normative References
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[I-D.ietf-idr-segment-routing-te-policy]
Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P., and
D. Jain, "Advertising Segment Routing Policies in BGP",
Work in Progress, Internet-Draft, draft-ietf-idr-segment-
routing-te-policy-26, 23 October 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-idr-
segment-routing-te-policy-26>.
[I-D.ietf-pce-segment-routing-policy-cp]
Koldychev, M., Sivabalan, S., Barth, C., Peng, S., and H.
Bidgoli, "Path Computation Element Communication Protocol
(PCEP) Extensions for Segment Routing (SR) Policy
Candidate Paths", Work in Progress, Internet-Draft, draft-
ietf-pce-segment-routing-policy-cp-18, 14 October 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-pce-
segment-routing-policy-cp-18>.
[I-D.ietf-spring-resource-aware-segments]
Dong, J., Miyasaka, T., Zhu, Y., Qin, F., and Z. Li,
"Introducing Resource Awareness to SR Segments", Work in
Progress, Internet-Draft, draft-ietf-spring-resource-
aware-segments-10, 12 October 2024,
<https://datatracker.ietf.org/doc/html/draft-ietf-spring-
resource-aware-segments-10>.
[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>.
[RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running
Code: The Implementation Status Section", BCP 205,
RFC 7942, DOI 10.17487/RFC7942, July 2016,
<https://www.rfc-editor.org/info/rfc7942>.
[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>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
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[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,
<https://www.rfc-editor.org/info/rfc8664>.
[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>.
[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>.
7.2. Informative References
[I-D.ietf-teas-ietf-network-slices]
Farrel, A., Drake, J., Rokui, R., Homma, S., Makhijani,
K., Contreras, L. M., and J. Tantsura, "A Framework for
Network Slices in Networks Built from IETF Technologies",
Work in Progress, Internet-Draft, draft-ietf-teas-ietf-
network-slices-25, 14 September 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-teas-
ietf-network-slices-25>.
[ZTE-IMP] "ZTE M6000-S Routers", 21 October 2023,
<https://www.zte.com.cn/china/product_index/ip_network/
item02/zxr10-m6000-s/zxr10_m6000_s.html>.
Appendix A. Acknowledgements
The authors would like to thank Detao Zhao for his suggestions and
comments.
Authors' Addresses
Weiqiang Cheng
China Mobile
China
Email: chengweiqiang@chinamobile.com
Wenying Jiang
China Mobile
China
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Email: jiangwenying@chinamobile.com
Ran Chen
ZTE Corporation
Nanjing
China
Email: chen.ran@zte.com.cn
Changwang Lin
New H3C Technologies
China
Email: linchangwang.04414@h3c.com
Geng Zhang
China Mobile
China
Email: zhanggeng@chinamobile.com
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