I have two FreeSWITCH servers that I need to gateway calls between. Sip_A is on a public network with a static IP address. Sip_B is on a private network that is NAT'd. I am trying to pass calls from devices connected to Sip_B, through Sip_A and on to another server. I am also trying to pass calls from Sip_A into Sip_B. I don't have access to the firewall at the location of Sip_B so I am not able to forward standard ports into Sip_B. I am fairly new to FreeSWITCH, so I'm not certain how to solve this problem well. Many of the documents I have read online recommend using ACLs and port forwards for this. However, the private network does not have a static IP address that I can give access to and, as mentioned, I cannot make port forwards. Instead, I have created an extension on Sip_A and a gateway on Sip_B that registers using the extension on Sip_A. That works fine for passing calls from Sip_B through Sip_A and on. Sip_B has been maintaining a registered connection to Sip_A through the NAT'd connection for several days now without trouble. Not knowing a better solution, I have been searching for a gateway configuration on Sip_A that would allow it to route calls back over the registered extension from Sip_B. I have not found a way to accomplish it yet. As an alternative, I have also tried without success to create a passive gateway on Sip_A that the gateway on Sip_B could register with. Any help is appreciated! Thanks, Robert