Re: [tsvwg] SCE / L4S and fragmentation

Bob Briscoe <> Mon, 16 March 2020 08:50 UTC

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To: Jonathan Morton <>, "Black, David" <>
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From: Bob Briscoe <>
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Date: Mon, 16 Mar 2020 08:50:43 +0000
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Subject: Re: [tsvwg] SCE / L4S and fragmentation
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Jonathan, [David, this one's for you too]

On 15/03/2020 23:35, Jonathan Morton wrote:
> Isolating one key point:
>> On 15 Mar, 2020, at 8:14 pm, Bob Briscoe <> wrote:
>> I (and David Black) have argued that a separate draft is needed to update fragment reassembly in RFC3168. Can you please accept that we are not going to update ECN fragmentation and reassembly in rfc6040update-shim. Then it can unblock and be published.
>> rfc6040update-shim is meant to be about encap and decap. It would allow this draft to become unstuck if it just said fragmentation and re-assembly is out of scope (which it is).
> I have said several times in the past few days that I agree with that approach, and I'm sure David Black is well aware of that.
> However, the -10 revision (which appears to be current) still contains the section and some language covering fragmentation and reassembly.  To be consistent with this approach, you need to update it to simply refer to RFC-3168 for the relevant semantics.  Then I think it will be possible to make progress.
I am waiting for David on that. After his email asking me to reaffirm 
RFC3168 behaviour in ecn-encap and rfc6040update-shim, I said I'd rather 
just say fragmentation is out of scope. So I'm waiting for David's 
response as doc shepherd before I commit any changes to the draft.

> We can discuss separately what, if anything, should be done to RFC-3168 on this topic.
>   - Jonathan Morton

Bob Briscoe