Re: [AVTCORE] multi session draft-ejzak-avtcore-rtp-subsessions-00.txt

["Ejzak, Richard P (Richard)" <[e-mail]>]

Harald Alvestrand wrote:
> That ("based on the negotiated payload types") is the part that doesn't
> seem natural to me.

I only mean by this that QoS treatment can take into account the characteristics of the expected payload.  I don't think we differ here.

> I'm suggesting that media lines should be grouped into RTP sessions,
> each of which is carried on a single transport connection. That's the
> reason why the BUNDLE extension is explicit about which sessions are
> part of the bundle; it's simple to define as many bundles as are needed
> in order to achieve one's differential-treatment goals.
> >   I would prefer to have a solution where we can assign differential
> treatment to flows within a transport connection.
> That's a complexity I don't see the need for. YMMV.

This seems to be the real issue.  We have a difference in understanding of requirements.  I thought that the multi session work was intended to remove the major limitations of the single session BUNDLE technique.  To me, the most significant limitation of BUNDLE is the inability to assign differential treatment to different media lines within a BUNDLE.  If we don't fix this I don't see a need to progress work on multi session within AVTCORE.  I agree with you that single session BUNDLE is adequate for all reasonable use cases without this requirement.  And differential treatment based on filtering on a SHIM header at the end of the IP payload is problematic in some implementations. 

Richard