I have a VPN set up between two sites. Each site has an RV120W router, connected to the internet through a broadband modem, so the setup looks like this:
Site 1 Internal Network <---> RV120W <---> BT Openreach Modem <---> Internet <---> BT Openreach Modem <---> RV120W <---> Site 2 Internal Network.
We have a working IPSEC VPN tunnel between the two sites, and can ping between sites no problem. Also working for file transfers, http etc.
I have a VoIP server with several SIP phones connected to it at Site 1. I have a couple of SIP phones at Site 2, which used to work fine using our old routers. However since moving to the RV120W I cannot get the SIP phones at Site 2 to connect to the server at Site 1 through the VPN.
I've tried playing with the port forwarding rules for the router at Site 2, but to no avail so far.