I am looking for more feedback on the following topic (not by Roni
or Ali).
The example in the draft is coming from a distribution source using
for example SAP (multicast distribution).
There are three entities in the communication. The multicast
distribution source, the unicast retransmission which also serves as
a feedback target and a client that wants to receive the multicast
stream and will ask for unicast resynchronization or retransmission.
This SDP is coming from the distribution source and according to the
authors specify the multicast address, the unicast transport address
for the RTCP receiver reports for the multicast (SSM), the uincast
transport address on the feedback target/retransmission server that
will be used by the clients to ask for retransmission streams using
RTCP-FB and the transport address on the client that will be used by
the feedback target to send the unicast RTP stream to.
Does this SDP look like it supplies all this information enabling
interoperable applications.
v=0
o=ali 1122334455 1122334466 IN IP4 rams.example.com
s=Rapid Acquisition Examples
t=0 0
a=group:FID 1 2
a=group:FID 3 4
a=rtcp-unicast:rsi
m=video 40000 RTP/AVPF 96
i=Primary Multicast Stream #1
c=IN IP4 224.1.1.1/255
a=source-filter: incl IN IP4 224.1.1.1 192.0.2.2
a=recvonly
a=rtpmap:96 MP2T/90000
a=rtcp:40001 IN IP4 192.0.2.1
a=rtcp-fb:96 nack
a=mid:1
m=video 40002 RTP/AVPF 97
i=Unicast Retransmission Stream #1 (Ret. Support Only)
c=IN IP4 192.0.2.1
a=recvonly
a=rtpmap:97 rtx/90000
a=rtcp:40003
a=fmtp:97 apt=96
a=fmtp:97 rtx-time=3000
a=mid:2
Thanks
Roni Even