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

[Gorry Fairhurst <[e-mail]>]

On 24/03/2021 13:53, Black, David wrote:
>> The interaction with DSCPs was revisited in 2018
>> (draft-briscoe-tsvwg-l4s-diffserv-00), after RFC8311 enabled such a
>> deployment experiment using ECT(1).  That which explains how the two
>> approaches interact, how they can be arranged to complement each other
>> and in which cases one can stand alone without needing the other.
> My recollection is that this draft was not taken forward due to lack of interest at the time.
>
> Thanks, --David

True, the discussion of Diffserv goes has to date gone in cycles - with 
few (if any) operators stepping-up and saying that they would like to 
deploy L4S with a DSCP.

Gorry

>
> -----Original Message-----
> From: tsvwg <[e-mail]> On Behalf Of Gorry Fairhurst
> Sent: Wednesday, March 24, 2021 8:47 AM
> To: Pete Heist; [e-mail]
> Subject: Re: [tsvwg] L4S DSCP (was: L4S drafts: Next Steps)
>
>
> [EXTERNAL EMAIL]
>
> So injecting a little more history here.
>
> Some previous discussions are:
>
> The earliest discussion of L4S in the IETF that I recall was in 2015.
> When discussing, it was known that RFC4774 would allow experimentation
> with a diffserv domain (e.g., as in RFC 6660), but the practicalities of
> deploying an end-to-end Internet transport required an RFC to use a
> method that was not protected by a DSCP. The discussion on whether the
> ECN Plus a Diffserv Codepoint (DSCP) was also noted in the appendix of
> draft-briscoe-tsvwg-ecn-l4s-id-00 in 2015.  R
>
> Tradeoffs that lead to using ECT(1) were described in the proposal to
> the AQM working group in draft-briscoe-aqm-dualq-coupled-00 in 2015.
>
> The interaction with DSCPs was revisited in 2018
> (draft-briscoe-tsvwg-l4s-diffserv-00), after RFC8311 enabled such a
> deployment experiment using ECT(1).  That which explains how the two
> approaches interact, how they can be arranged to complement each other
> and in which cases one can stand alone without needing the other.
>
> Gorry
>
> On 24/03/2021 11:01, Pete Heist wrote:
>> I'll just add to the sentiment that I think the use of DSCP is still
>> worthy of consideration. Beyond the use of a single DSCP on all
>> traffic, there may be other alternatives that address at least some of
>> the concerns in B.4.
>>
>> Pete