Re: [sfc] The SFC WG has placed draft-eastlake-sfc-nsh-ecn-support in state "Candidate for WG Adoption"

[Tal Mizrahi <[e-mail]>]

Hi,

I reviewed the draft, and I believe it is worth pursuing in the working
group.

Comments:

- Section 1.3 / Section 4: these sections discuss how the ingress node
(classifier) may react to the congestion. However, it seems that there may
be a conflict if the egress node both propagates the ECN to the destination
AND sends a congestion feedback to the ingress node. In this case traffic
may be throttled by two nodes (traffic source and NSH classifier). It would
be helpful if the draft clarifies whether these two behaviors are mutually
exclusive, or how they coexist.

- The draft implies that in a network that uses ECN-in-NSH the Ingress and
Egress nodes must be ECN aware, while the SFFs and SFs may be ECN unaware,
allowing interoperability with older SFF/SF nodes. I would suggest to state
this explicitly in the introduction.

- "It MAY instead be set to ECT(1) if the NSH domain supports the
experimental L4S capability [RFC8311], [ecnL4S]."
  This sentence is confusing from an implementer's perspective. Does the
"MAY" here allow interoperability between the two approaches (RFC3168/
RFC8311)? Please clarify in the draft whether ECN-in-NSH-aware nodes are
expected to be implemented as defined in [RFC3168] or as in [RFC8311], or a
combination of both.

Cheers,
Tal.

On Thu, Jan 3, 2019 at 7:11 AM IETF Secretariat <
[e-mail]> wrote:

>
> The SFC WG has placed draft-eastlake-sfc-nsh-ecn-support in state
> Candidate for WG Adoption (entered by Joel Halpern)
>
> The document is available at
> https://datatracker.ietf.org/doc/draft-eastlake-sfc-nsh-ecn-support/
>
> Comment:
> This starts the WG call for adoption of this draft.
> Please respond to the list, indicating support for this as a work item of
> the
> working group with this document as the basis for the work, or objection to
> the working group adopting this item as a working group draft.
>
> The authors should confirm to the chairs and WG secretary that all IPR
> known
> to them relevant to this draft has been disclosed.
>
> The working group adoption call will last 2 weeks, ending at the end of the
> day on Thursday, January 17 2019 COB somewhere.
>
> Thank you,
> Joel
>