Re: [Dart] [tsvwg] Comments on draft-ietf-tsvwg-rtcweb-qos-00

[Brian E Carpenter <[e-mail]>]

On 26/06/2014 01:23, Gorry Fairhurst wrote:
...
>> Sure, however, my point was that simply injecting traffic marked with
>> a DSCP for a PHB that normally requires prior admission control is
>> somewhat problematic: either guarantees for already admitted flows
>> are violated or such traffic has to be dropped.
> 
> I see a potential problem here, if this becomes a default: If widely
> deployed using EF, the traffic will likely result in this DSCP being
> ignored/dropped (not given you EF properties0)or in breaking EF
> properties for other flows (which needs to be policed).

If you look at RFC3246 (the EF specification) you will find
these words:

 the rate at which EF
 traffic is served at a given output interface should be at least the
 configured rate R, over a suitably defined interval, independent of
 the offered load of non-EF traffic to that interface.

In other words, if you do not apply admission control to
EF traffic, excess traffic *will* be discarded, because EF
has a strict maximum rate.

    Brian