Re: [aqm] I-D Action: draft-ietf-aqm-recommendation-04.txt

I agree that if AQM is deployed it would be good to revisit this topic
(and note that some methods include a notion of flow-queuing, which also
interacts). Coincidentally this at a time when TSVWG is trying to help
inter-domain diffserv connection...

As I noted at the last IETF TSV WG meeting, this topic has the attention
of  "this" TSV WG Chair - and I think it would be useful to AT LEAST
review where we have reached, although I suggest "what do we do next"
discussions belong on the TSV mailing list.

Feel free to take this topic up there!

Gorry
(TSVWG Co-Chair)

> Hi,
>
> On 13.05.2015 at 07:01 Fred Baker (fred) wrote:
>>> On May 12, 2015, at 9:06 PM, Simon Barber <simon@superduper.net>
>>> wrote:
>>>
>>> Where would be the best place to see if it would be possible to
>>> get agreement on a global low priority DSCP?
>>
>> Id suggest
>>
>> https://tools.ietf.org/html/rfc4594 4594 Configuration Guidelines
>> for DiffServ Service Classes. J. Babiarz, K. Chan, F. Baker. August
>> 2006. (Format: TXT=144044 bytes) (Updated by RFC5865) (Status:
>> INFORMATIONAL)
>>
>> It refers to
>>
>> [QBSS]     "QBone Scavenger Service (QBSS) Definition", Internet2
>> Technical Report Proposed Service Definition, March 2001.
>>
>> (http://mgoutell.free.fr/gridftp/QBSS/qbss-definition.txt) and
>> states that
>
> While QBSS may have gotten more attention the original idea is here:
> https://tools.ietf.org/html/draft-bless-diffserv-lbe-phb-00
> from there it finally went to a PDB definition in RFC 3662 as you
> already found out, because the DiffServ chairs didn't want it to be
> defined as PHB.
>
>>> Within QBone, traffic marked with DSCP 001000 (binary) shall be
>>> considered in the QBSS class and should be given the service
>>> described in this document.  Notice that while DSCP values
>>> generally have only local significance we are assigning global
>>> significance to this particular codepoint within QBone.  We refer
>>> to packets marked with DSCP 001000 as being marked with the "QBSS
>>> code point.
>>
>>
>> Thats where we came up with recommending CS1 (001000) for the
>> traffic class.
>
> CS1 is maybe a problem because originally (rfc 2474) CS1 means better
> priority than CS0. At that point in time of RFC3662 the discussion was
> to use CS1, because also in 802.1p 1 means "background". However,
> this inconsistency makes it now hard to rely on any semantics of DSCP
> CS1. IIRC the Diffserv chairs were opposed to spend another DSCP on LE
> and therefore proposed to use an existing one. In retrospect, this
> seems to have been a wrong decision given the problems of rtcweb and
> so on these days.
>
>> Im pretty sure the latter ultimately resulted in an RFC, but for
>> some reason Im not finding it. The closest thing I see is
>
> Yes, https://tools.ietf.org/html/rfc3662.
>
> Regards,
>  Roland
>
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