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gwhiteCL / NQBdraft

IETF draft on Non-Queue-Building Per-Hop-Behavior
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Should we explicitly document the use of DSCP 5 in RFC8100 interconnections? #49

Closed gwhiteCL closed 2 weeks ago

gwhiteCL commented 2 months ago

BC commented (in https://mailarchive.ietf.org/arch/msg/tsvwg/ej3Rk8FVIuopmM0xMwZqndECTGs/)

In 4.4 "Cross-domain usage and DSCP Re-marking": I think there needs to be an explanation of how this section relates to RFC 8100

RG responded (https://mailarchive.ietf.org/arch/msg/tsvwg/Qi-nsXhDwbVAgGThPWtMfdEOxgs/):

Section 4.4: If NQB support is extended across a DiffServ domain boundary, the interconnected networks agreeing to support NQB SHOULD use the DSCP value 45 (decimal) for NQB at network interconnection, unless a different DSCP is explicitly documented in the TCA (Traffic Conditioning Agreement, see [RFC2475]) for that interconnection.

[RG] If RFC 8100 is agreed and operational and the provider interconnection link is no bottleneck, my suggestion would be to explicitly document usage of DSCP 5 (dec.) The sending party should re-mark NQB traffic to DSCP dec. 5 and the receiving party should classify NQB traffic by that DSCP.

BC concluded (https://mailarchive.ietf.org/arch/msg/tsvwg/CcytdksJWAxZ20xm1U7qYALwLD0/):

I think your first suggestion is useful, and sufficient.

gwhiteCL commented 2 months ago

Earlier versions of the draft included the requirement to re-mark NQB traffic with DSCP 5 at all interconnections. One of the objections to this was a concern about registering two DSCPs with IANA, given the relatively small number of unassigned DSCPs that remain. Is there a way to explicitly document the use of DSCP 5 in this limited context that won't run into the same objection?

gwhiteCL commented 1 month ago

In some offline discussions, it was pointed out that it really isn't a viable option to reference a second, pool 3 DSCP in a standards track document without registering it with IANA. Instead we could add the following proposed clarification (new text in bold):

If NQB support is extended across a DiffServ domain ..... TCA (Traffic Conditioning Agreement, see [RFC2475]) for that interconnection. If [RFC8100] is operational between interconnected domains, the receiving domain may prefer a different DSCP for NQB traffic that allows for a DSCP range-based classification for the Default / Elastic Treatment Aggregate. Similar to the handling of DSCPs ......