One SBC serves as the proxy of two Softx3000s. softx3000_A serves user-group-A, and softx3000_B for user-group-B. However, it prompts error when using addrmap command to configure the mapping of softx3000_B, and the configuration fails. The topology is:
The address of both Softx3000 is 220.127.116.11 and 18.104.22.168 respectively; the address of SBC server interface is 22.214.171.124, and that of client is 10.0.0.1.
The original command is: sbc addrmap clientaddr 10.0.0.1 serveraddr 126.96.36.199 softxaddr 188.8.131.52
When using the following command to configure the mapping of softx3000_B, error is prompted, and the configuration is failed:
sbc addrmap clientaddr 10.0.0.1 serveraddr 184.108.40.206 softxaddr 220.127.116.11
The difference between SBC and a router lies in that the master IP and slave IP can belong to the same sub-net at the same interface of SBC.
At the interface connecting to Internet, configure the slave IP by the following command: ip address 18.104.22.168 255.255.255.0 sub
At the interface connecting to the user, configure the slave IP by the following command: ip address 10.0.0.2 255.255.255.0 sub
Use addrmap command to set up another group of mapping: sbc addrmap clientaddr 10.0.0.2 serveraddr 22.214.171.124 softx3000 126.96.36.199
In the topology, there are two groups of mapping and each uses the same serveraddr and clientaddr. However, it may result in chaotic session table, so the configuration is not permitted.
Solution: Configure one slave IP address for upstream and downstream interfaces of SBC respectively, which can be used to set up mapping of softx3000_B.
The solution is recommended when one SBC serves as proxy for two or more softx3000s.