[AG-TECH] getting raw rtp addresses of streams

Andrew Rowley Andrew.Rowley at manchester.ac.uk
Tue Oct 5 09:47:32 CDT 2004


As far as I am aware, each RTP message is sent with an SSRC identifier.
This is unique for each source.  If you capture all the packets with the
same SSRC, you should get all the packets from one stream.

To tell which SSRC refers to which stream, you need to look at the RTCP
packets (on the port number above that which the RTP channel is connected
to).  The packets there will carry the same SSRC number with all the other
identifiers of the source, such as the origin.  Note that it might be a bad
idea to use the sender IP address of the UDP packet to indicate the source
of the packet.  This is because some people will be connected via a
Unicast-Multicast bridge.  Using this IP address will most likely give the
IP address of the bridge, not of the original sender.

See http://www.faqs.org/rfcs/rfc1889.html for details of RTP.

Andrew :)

Access Grid Support Centre,
SVE Group,
Manchester Computing,
Kilburn Building,
University of Manchester,
Oxford Road,
M13 9PL, 
Tel: +44(0)161-275 0615
Email: Andrew.Rowley at manchester.ac.uk 

-----Original Message-----
From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On Behalf
Of david ignacio
Sent: 01 October 2004 19:51
To: ag-tech at mcs.anl.gov
Subject: [AG-TECH] getting raw rtp addresses of streams

I am looking into a process for converting AG Video streams into
Quicktime.  Is there a method for obtaining the raw rtp addresses of
arbitrary people's video streams?


More information about the ag-tech mailing list