Date Added: Jan 2010
Today, SIP is a protocol par Excellence in the field of communication over Internet. But, the fact that it belongs to the application layer constitutes a weakness vis-?-vis the NAT traversal. This weakness is due to the way in which the server replies to the requests of clients on the one hand. On the other, it is caused by the dynamic allocation of UDP ports for emission and reception of packets RTP/RTCP. The TURN Protocol may face this weakness. However, its use requires a certain number of exchanges between the clients and a TURN server before establishing the multimedia sessions and this increase the latent time.