The rtptools distribution consists of a number of small applications that
can be used for processing RTP data.

rtpplay
     play back RTP sessions recorded by rtpdump
rtpsend
     generate RTP packets from textual description, generated by hand or
     rtpdump
rtpdump
     parse and print RTP packets, generating output files suitable for
     rtpplay and rtpsend
rtptrans
     RTP translator between unicast and multicast networks

WWW: http://www.cs.columbia.edu/irt/software/rtptools/