I am using ser to solve the nat problem,

In my environment:  invite A-->SER-->B

 

 

1. SER receive the invite message REQA from A(invite B)

2. SER judge the use B, if the B is in public network, will fix nat in the REQA message

    if judge the B is in private network , will not fix anything

 

and I want to know, how to judge the B's network, when the SER receive the INVITE from A?

Is there any examle code used in ser.cfg

 

 

thank you very much