Method for passing through network address conversion

Abstract

The method includes steps: after receiving IP message of user's logon request sent from user terminal UE, SBGF entity obtains IP address / port of source; after carrying out NAT address conversion for IP message head, SBGF entity sends it to AF entity; AF entity obtains IP address / port of user and address / port of IP message converted by SBGF entity carried by load of message; after successful logon, AF entity saves address / port of IP message converted by SBGF entity, and sends IP address / port of user carried by message load to SBGF entity; SBGF entity compares IP address of source in user logon message with information of user's IP address / port carried in message load sent from the AF entity; if not identical, then it is determined that there is NAT equipment existed between UE and SBGF entity; sending keep alive message of NAT to UE regularly. The method lighten handling burden for AF.

Description

technical field [0001] The invention relates to the field of packet service technology, in particular to a method for traversing network address translation (NAT) in a packet service network. Background technique [0002] Due to insufficient IP addresses or security considerations, a large number of NAT devices are deployed at the egress of the access network and enterprise network. These NAT devices save a large number of IP addresses for operators or enterprises, enabling various data services to be carried out normally. But at the same time, due to the existence of the NAT device, the session service cannot be carried out normally. This is mainly because the NAT device changes the IP address of the message and isolates different address domains at the same time, while the address of the media stream identified in the signaling message is still the original private IP address. The text cannot be forwarded normally, and communication cannot be carried out. The above probl...

AI Technical Summary

Problems solved by technology

[0015] In the above networking situation, due to the presence of NAT devices in the carrier network, that is, NAT conversion needs to be performed in the BGF, and since the application functional entity, such as P-CSCF, is a centralized large-capacity control device, from the perspective of networking and security Consider that the P-CSCF is usually located in the central computer room of the operator's network, not at the network border. At this time, the signaling channel between the NAT and the P-CSCF in the client network may not be established in the operator's network, so , it may not be possible for signaling packets to traverse the NAT device in the above-mentioned networking

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