Re: [tsvwg] L4S DSCP (was: L4S drafts: Next Steps)

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Hi Gorry,

One detail only, otherwise we are in line otherwise, I think

> Then innocent bystanders may get hit and a specified DSCP might allow for protection.

[GF] The bystanders are those impacted by a "CE-marking from a non-L4S router" that is congested, but where the other traffic responds using L4S.

[GF] Is this any different to the first operator not forwarding the ECT(1) codepoint?

[GF] I do wonder if this proves a real problem whether the community might deprecate CE-marking of ECT(0) in non-L4S devices, I wonder in future how much hardship this would cause, especially if L4S were to be widely deployed.

[RG] In the case of an operator sending L4S traffic, the source of a "CE-marking from a non-L4S router" must be upstream of the terminal. That is likely a policy point of the operator or an external network. The former doesn't apply and I doubt that the latter is to be expected. I'd expect the terminals to be deployed for some experiment (and users are either operator employees or friendly volunteers), so the contact with external networks sending "CE-marking from a non-L4S router" might be rare (I'd wonder about that - where's the bottleneck, a peering interface?).

Regards,

Ruediger