MediaProxy – RTP Proxy
MediaProxy is an RTP which, used together with SipProxy, allows media streams based on the UDP transport protocol (RTP for voice and video over IP, T.38 for fax over IP) to travel on a determined path across different networks without altering the origin and final destination of the UDP datagrams.
This means that data can travel over different types of network simply, reliably and safely, even with NAT.
MediaProxy implements a dynamic method of Call Admission Control (when there is a request to add a new data stream, it verifies whether this can be supported by the system taking into account the maximum bandwidth declared in both directions and the bandwidth used during the last 10 seconds).
As an option for protocols based on UDP transport, MediaProxy implements the symmetric mode (for further details see the document RFC 4961 – Symmetric RTP/RTP Control Protocol (RTCP)) which allows media to flow bi-directionally even from a remote client which is in turn behind NAT and which has not adopted any specific method of NAT transit.