rtpproxy 0.3-2 (lpia binary) in ubuntu intrepid

 RTP (Realtime Transport Protocol) proxy is an application that can be used
 to relay RTP media streams through a server in the public internet. That
 is often necessary when dealing with SIP (Session Initiation Protocol)
 user agents that are behind NAT (Network Address Translator).
 .
 The rtpproxy can be used in conjunction with nathelper module of SER
 (SIP Express Router). When nathelper module of SER detects that a user
 agent will need to relay media through a host in the public internet,
 it will contact rtpproxy and ask it to allocate a public IP and port
 the user agent can send it's RTP streams to. That information will
 then be communicated to the user agent in SDP (Session Description
 Document).