Liaison statement
Response to "LS on new work item QSTR.MVC “Method for Verifying Conformance to SRv6"

We would like to thank the ITU-T-SG-11 for informing the IETF about the new
work item QSTR.MVC "Method for Verifying Conformance to SRv6" [1].
Specifically, we appreciate that the ITU is soliciting feedback for a work
related to an IETF-developed technology: Segment Routing over IPv6 (SRv6). We
acknowledge that the technical report does not aim to alter any SRv6
specification or seek to specify new SRv6 requirements outside of IETF's work.

There are several Working Groups (WGs) in the IETF (mainly SPRING, 6MAN, BMWG,
BESS, IDR, LSR, PCE, RTGWG, TEAS, and OPSAWG) that are working on SRv6-related
specifications. The links to all active IETF WGs can be found at [2]. Further,
the list of RFCs published by each of the WG are available on each WG's page.

The specifications listed as "Core SRv6 Standards" in the attached document to
the LS are a subset of SRv6-related Proposed Standards published so far by the
IETF. The IETF does not identify a subset of SRv6-related specifications as
"Core SRv6 Standards". We understand that this is a classification that it is
specific to ITU-T-SG-11.

Unlike what is stated in the report, some of the listed RFCs (e.g., RFC 8665,
RFC 8666, and RFC 8667) do not apply for SRv6, but for SR-MPLS. Some RFCs
(e.g., RFC 9256) apply for both SRv6 and SR-MPLS. A review of the RFCs listed
on the WGs pages will provide information on their applicability to SRv6. Also,
the name of some of the listed RFCs should be corrected as follows:

RFC 8665: OSPF Extensions for Segment Routing

RFC 8666: OSPFv3 Extensions for Segment Routing

RFC 8667: IS-IS Extensions for Segment Routing

Note that some other SRv6-related specifications are being finalized by SPRING.
Notably, "Compressed SRv6 Segment List Encoding (CSID)" [3] has been approved
and is planned for publication by the IETF in the coming few months.

When referring to aspects of the IETF standards as "mandatory" or "optional",
it is recommended to provide a reference to the specific section and text from
the specific RFC. This approach avoids misalignment with IETF standards. For
example, RFC 8754 does not specify the usage of "Tag" in the SRH (it only
introduces the "Tag" field in the SRH), but the ITU technical report marks
"Packet Tagging and Tag Processing" as mandatory. There are other similar
misalignments that need to be adjusted.

While ensuring better interoperability is one of the key objectives of the IETF
specifications, the IETF does not produce formal conformance test suites per
se. However, the IETF has a WG that is chartered for Benchmarking Methodology
(BMWG WG) [4].

For information, the BMWG is actively working on an SR-related benchmarking
methodology specification [5] with a focus on performance for both SRv6 and
SR-MPLS. This specification is planned for publication by the end of 2025.

For future collaboration on these matters, we encourage the use of BMWG WG
mailing list [6] as the most effective and expedient way of exchanging
information, answering questions, and progressing any work.

For specific questions related to a given SRv6-related specification, we
encourage the use of the mailing list of the WG that produced that
specification.

OPS Area Directors: Mohamed Boucadair & Mahesh Jethanandani

Routing Area Directors: Gunter Van de Velde, Jim Guichard, & Ketan Talaulikar

INT Area Directors: Éric Vyncke & Erik Kline

BMWG WG Chairs: Giuseppe Fioccola & Sarah Banks

SRV6OPS WG Chairs: Daniel Voyer, Dhruv Dhody, & Weiqiang Cheng

SPRING WG Chairs: Alvaro Retana, Bruno Decraene, & Joel M. Halpern

OPSAWG WG Chairs: Benoît Claise & Joe Clarke

6MAN WG Chairs: Bob Hinden & Jen Linkova

References:

[1] https://datatracker.ietf.org/liaison/1983/

[2] https://datatracker.ietf.org/wg/

[3] https://datatracker.ietf.org/doc/draft-ietf-spring-srv6-srh-compression/

[4] https://datatracker.ietf.org/group/bmwg/about/

[5] https://datatracker.ietf.org/doc/draft-ietf-bmwg-sr-bench-meth/

[6] https://www.ietf.org/mailman/listinfo/bmwg