Network Working Group W. Cheng
Internet-Draft China Mobile
Intended status: Informational G. Mishra
Expires: January 13, 2022 Verizon Inc.
Z. Li
Huawei Technologies
A. Wang
China Telecom
Z. Qin
China Unicom
C. Fan
New H3C Technologies
July 12, 2021
Design Consideration of IPv6 Multicast Source Routing (MSR6)
draft-cheng-spring-ipv6-msr-design-consideration-00
Abstract
This document discusses the design consideration of IPv6 source
routing multicast solution.
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.
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 January 13, 2022.
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Internet-Draft Design Consideration of MSR6 July 2021
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Design Consideration . . . . . . . . . . . . . . . . . . . . 3
3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . 5
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
7. Normative References . . . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
Multicast could provide efficient P2MP service without bandwidth
waste. The increasing amount of live video traffic in the network
bring new requirements for multicast solutions. The existing
multicast solutions request multicast tree-building on control plane
and maintaining end-to-end tree state per flow, which impacts router
state capacity and network convergence time. There has been a lot of
work in IETF to simplify service deployment, in which Source Routing
is a very important technology, including SRv6, BIER, etc. Source
routing is able to reduce the state of intermediate nodes and
indicate multicast forwarding in the ingress nodes, which could
simplify multicast deployment. Source routing requires sufficient
flexibility on the forwarding plane and IPv6 has the advantage with
good scalability. Therefore, it is important to simplify multicast
deployment and meet high quality service requirements with IPv6
Source Routing based multicast.
This document discusses the design consideration of IPv6 multicast
source routing (MSR6) solution. The definition of the new IPv6
multicast source routing solution is out of the scope of this
document.
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2. Design Consideration
Firstly, MSR6 needs to support the basic multicast functionalities,
including:
o P2MP Forwarding: replicate and forward multicast packet to the
next replication nodes;
o Multicast Flow Overlay: multicast service, such as MVPN
o P2MP OAM functions: Ping/Traceroute/BFD
In addition to this, it is necessary for MSR6 to meet the need of
high quality service with high reliability, including:
o Traffic Engineering: explicit path specification to satisfy
different kinds of requirements
o FRR
o E2E Protection
o Advanced network measurement functions, including: performance
measurement and In-situ Flow Information Telemetry, which is the
basis for traffic engineering and high quality transport service.
The IPv6 multicast source routing should take use of the advantages
of source routing to reduce the state of the network as much as
possible. That is, it should satisfy the above requirements with
high scalability.
However, MSR6 is not about starting from scratch. The existing IETF
work should be reused as much as possible:
o BIER
Bit Index Explicit Replication (BIER) defined in [RFC8279] is an
architecture providing optimal multicast forwarding without requiring
intermediate routers to maintain any per-flow state by using a
multicast-specific BIER header. BIER use bitstring in the BIER
header to indicate leaf nodes which gives an efficient solution for
Best Effort multicast flow without the requirement of Traffic
Engineering.
o SRv6([RFC8986])
SRv6 has advantages in indicating explicit paths, which brings
convenience for unicast TE and FRR. MSR6 TE should refer to the
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experience of SRv6. In addition, SRv6 provides flexible path
programming capability with the definition of different type of
segments. MSR6 could make use the of existing segments in the design
of TE/FRR . For example, path segment
([I-D.ietf-spring-srv6-path-segment]) could help to enhance the
performance measurement capability. In the meantime, SRv6
compression ([I-D.srcompdt-spring-compression-requirement]) is under
discussion to reduce encapsulation overhead, which could also be
reused by MSR6.
o The existing and ongoing IPv6 extensions
1) Existing functionalities including fragmentation and security
Multicast packets need to be fragmented and secured as they pass
through the IPv6 network. This can be done using IPv6 Fragmentation
and ESP(Encapsulating Security Payload) defined in [RFC8200]. Work
about Path MTU [I-D.ietf-idr-sr-policy-path-mtu] which supports
fragmentation, is also under discussion. All these existing work
should be reused in the MSR6.
2) New network functionalities based on the ongoing IPv6 Extensions,
including Network Slicing, Deterministic Networking(DetNet),
IOAM.etc.
Network slicing ([I-D.ietf-teas-ietf-network-slices]) and DetNet
([RFC8655]) are being introduced to satisfy the quality service
requirements of critical services. IOAM ([I-D.ietf-ippm-ioam-data])
is also introduced to implement in-situ network measurement. IPv6
data plane is being used to support network slicing
([I-D.li-6man-e2e-ietf-network-slicing] and
[I-D.dong-6man-enhanced-vpn-vtn-id]), Detnet
([I-D.geng-spring-srv6-for-detnet] and
[I-D.geng-spring-sr-redundancy-protection]), IOAM
([I-D.ietf-ippm-ioam-data]), etc. Multicast service can also benefit
from these new network functionalities to improve quality of service.
MSR6 could reuse the ongoing work based on IPv6 extensions to
implement the functionalities for multicast services.
3) Future possible work based on IPv6 extensions, including
Application Aware Network (APN)
APN ([I-D.li-apn-framework]) is used to provide more granular
services, which can use IPv6 extension header to carry APN
information for the purpose of steering traffic, etc. MSR6 can
combine with APN to map the traffic to different Network-based
multicast services/functionalities according to the APN information
in the IPv6 data plane.
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4) MSR6 is also supposed to be started at the Host based on IPv6
In [RFC8754], it is supposed that a host can originate the IPv6
source routing packet. MSR6 should take use of the native IPv6
design and support originating the IPv6 packet by the host.
3. Conclusion
A new IPv6 multicast source routing solution is requested based on
the design consideration listed above.
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
6. Acknowledgements
7. Normative References
[I-D.dong-6man-enhanced-vpn-vtn-id]
Dong, J., Li, Z., Xie, C., and C. Ma, "Carrying Virtual
Transport Network Identifier in IPv6 Extension Header",
draft-dong-6man-enhanced-vpn-vtn-id-03 (work in progress),
February 2021.
[I-D.geng-spring-sr-redundancy-protection]
Geng, X., Chen, M., and F. Yang, "Segment Routing for
Redundancy Protection", draft-geng-spring-sr-redundancy-
protection-02 (work in progress), February 2021.
[I-D.geng-spring-srv6-for-detnet]
Geng, X., Li, Z., and M. Chen, "SRv6 for Deterministic
Networking (DetNet)", draft-geng-spring-srv6-for-detnet-01
(work in progress), July 2020.
[I-D.ietf-idr-sr-policy-path-mtu]
Li, C., Zhu, Y., Sawaf, A. E., and Z. Li, "Segment Routing
Path MTU in BGP", draft-ietf-idr-sr-policy-path-mtu-02
(work in progress), November 2020.
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Internet-Draft Design Consideration of MSR6 July 2021
[I-D.ietf-ippm-ioam-data]
Brockners, F., Bhandari, S., and T. Mizrahi, "Data Fields
for In-situ OAM", draft-ietf-ippm-ioam-data-12 (work in
progress), February 2021.
[I-D.ietf-spring-srv6-path-segment]
Li, C., Cheng, W., Chen, M., Dhody, D., and R. Gandhi,
"Path Segment for SRv6 (Segment Routing in IPv6)", draft-
ietf-spring-srv6-path-segment-00 (work in progress),
November 2020.
[I-D.ietf-teas-ietf-network-slices]
Farrel, A., Gray, E., Drake, J., Rokui, R., Homma, S.,
Makhijani, K., Contreras, L. M., and J. Tantsura,
"Framework for IETF Network Slices", draft-ietf-teas-ietf-
network-slices-00 (work in progress), April 2021.
[I-D.li-6man-e2e-ietf-network-slicing]
Li, Z. and J. Dong, "Encapsulation of End-to-End IETF
Network Slice Information in IPv6", draft-li-6man-e2e-
ietf-network-slicing-00 (work in progress), April 2021.
[I-D.li-apn-framework]
Li, Z., Peng, S., Voyer, D., Li, C., Liu, P., Cao, C.,
Ebisawa, K., Previdi, S., and J. N. Guichard,
"Application-aware Networking (APN) Framework", draft-li-
apn-framework-02 (work in progress), February 2021.
[I-D.srcompdt-spring-compression-requirement]
Cheng, W., Xie, C., Bonica, R., Dukes, D., Li, C., Shaofu,
P., and W. Henderickx, "Compressed SRv6 SID List
Requirements", draft-srcompdt-spring-compression-
requirement-06 (work in progress), March 2021.
[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>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
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[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>.
[RFC8296] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Tantsura, J., Aldrin, S., and I. Meilik, "Encapsulation
for Bit Index Explicit Replication (BIER) in MPLS and Non-
MPLS Networks", RFC 8296, DOI 10.17487/RFC8296, January
2018, <https://www.rfc-editor.org/info/rfc8296>.
[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>.
[RFC8663] Xu, X., Bryant, S., Farrel, A., Hassan, S., Henderickx,
W., and Z. Li, "MPLS Segment Routing over IP", RFC 8663,
DOI 10.17487/RFC8663, December 2019,
<https://www.rfc-editor.org/info/rfc8663>.
[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>.
Authors' Addresses
Weiqiang Cheng
China Mobile
Email: chengweiqiang@chinamobile.com
Gyan Mishra
Verizon Inc.
Email: gyan.s.mishra@verizon.com
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Zhenbin Li
Huawei Technologies
Email: lizhenbin@huawei.com
Aijun Wang
China Telecom
Email: wangaj3@chinatelecom.cn
Zhuangzhuang Qin
China Unicom
Email: qinzhuangzhuang@chinaunicom.cn
Chi Fan
New H3C Technologies
Email: fanchi@h3c.com
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