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

[Donald Eastlake <[e-mail]>]

Hi Tal,

On Mon, Jan 7, 2019 at 2:57 AM Tal Mizrahi <[e-mail]> wrote:
>
> Hi,
>
> I reviewed the draft, and I believe it is worth pursuing in the working group.

Thanks for the support.

> 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.

That is a reasonable consideration and the draft should probably talk
about it. I think some actions by the NSH classifier could cause
problems but there are other NSH classifier actions that would be OK.

> - 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.

OK.

> - "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.

I agree we need to clarify that.

Thanks,
Donald
===============================
 Donald E. Eastlake 3rd   [phone] (cell)
 1424 Pro Shop Court, Davenport, FL 33896 USA
 [e-mail]

> 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