Subject: [straw] My comments for WGLC on draft-ietf-straw-b2bua-rtcp-03

From: "Roni Even" <[email-masked]>
Date: Thu, 26 Feb 2015 19:33:45 +0200

Hi,

In general I am not sure what is the scope of the b2bua described here. My
understanding is that this entity is only handling point to point
connections and as  such the relevant topologies from
draft-ietf-avtcore-rtp-topologies-update-05 are the point to point ones
discussed in sections 3.1 and 3.2 and not the selective forwarding middlebox
from section 3.7 mentioned in section 3.2 of this document.

I also think that if this b2bua also handles multipoint cases than it does
not discuss it at all.

On the point to point case need to mention the case of SSRC multiplexing and
how it reflects in the case of aggregated RTCP reports from multiple SSRCs
form the same endpoint .

As for media terminator, if they do not buffer information than they MUST
maintain end to end relation, for example they cannot not send RRs on
packets that were not received by the remote site if they want to support
end to end NACKs. I think that for RTCP they will behave the same as media
aware relays which will make sense also for XR reports to report end to end
QoS. 

Some editorial issues:

1.       You should only reference
draft-ietf-avtcore-rtp-topologies-update-05 and not RFC5117 which will be
obsolete by the new document.

2.       On CNAME maybe reference RFC6222 recommending its usage.

BTW: My view is that if the purpose of  this document is to specify behavior
of any media handling middle box for point to point or multipoint topologies
as described in draft-ietf-avtcore-rtp-topologies-update-05 it should have
been discussed in AVTcore. 

Thanks

Roni Even