Method for realizing external network user crossing NAT equipment

Abstract

This invention relates to a method for realizing crossing over NAT equipments by external users including: after registering successfully to a net-guard, a GW in a private net sends a request for connecting the call signaling to the net-guard to set up related TCP connection and store it, then, when an external user calls the user under the GW of the private net, the net-guard sends the received call message to the user under the GW of the private net via the stored TCP connection corresponding to said GW, therefore, when an external net calling user calls the private net user connected with H323 GW under the NAT device, this invention can ensure it to call the called private net user smoothly via the net-guard and related TCP connection.

Description

technical field [0001] The invention relates to the technical field of network communication, and in particular to a method for realizing traversal of NAT equipment by external network users. Background technique [0002] In the existing communication network, when at least one GW (gateway) of the communication parties is located in the private network behind the NAT (Network Address Translation) server, the user connected to the GW in the private network is called from outside the private network The call will fail. This is because after the call initiated from outside the private network reaches the GK (gatekeeper), the gatekeeper GK can only connect the call to the corresponding NAT device through the corresponding TCP (Transmission Control Protocol), and on the NAT device, then Since there is no mapping relationship between the GW in the private network and the NAT device, the SETUP (establishment) message of Q931 cannot be transmitted to the private network, so the GW ...

AI Technical Summary

Problems solved by technology

[0002] In the existing communication network, when at least one GW (gateway) of the communication parties is located in the private network behind the NAT (Network Address Translation) server, the user connected to the GW in the private network is called from outside the private network will fail to call successfully

This is because after the call initiated from outside the private network reaches the GK (gatekeeper), the gatekeeper GK can only connect the call to the corresponding NAT device through the corresponding TCP (Transmission Control Protocol), and on the NAT device, then Since there is no mapping relationship between the GW in the private network and the NAT device, the SETUP (establishment) message of Q931 cannot be transmitted to the private network, so the GW in the private network will not be able to receive the call, that is, the call between the calling party and the called party cannot build success

[0003] like figure 1 As shown, when the telephone user with the number 5001 calls the telephone user with the number 6001, the corresponding SETUP message is sent to the corresponding NAT device through the Internet (Internet) and GK, but there is no address mapping of the GW in the private network on the NAT device Therefore, the NAT device cannot know which user connected to the SETUP message will be sent to, and therefore cannot transmit the SETUP message to the called user end

Images