NAT PROCESSING METHOD, DEVICE AND SYSTEM FOR CALLS BETWEEN CLIENTS OF PRIVATE NETWORK AND CLIENTS OUT OF NETWORK

摘要

The present invention relates to the technical field of communications. Disclosed in an embodiment of the present invention are an NAT processing method, device and system for calls between clients of a private network and clients out of network, solving the technical problem of unable to pass through NAT and FW when a proxy server and a private network client are in the same private network. The processing method for the NAT device comprises: allocating an idle public network address and port for the private network address and port of the private network client in the SDP portion of an SIP packet sent by a server, and storing the mapping relation; performing NAT ALG processing to the SIP packet, and converting the private network address and port in the SDP portion of the SIP packet into the public network address and port according to the mapping relation. The NAT device comprises a processor and a storage device for realizing the above functions. The calling system comprises the NAT device and the proxy server. The present invention is applicable for implementing network telephone call.