We are setting up a remote callcenter and I need to use some short of VPN tunneling to route SIP-data to our IP-PBX (asterisk). Currently we are using openvpn installed in each of the agents machines but I am looking at a more streamlined solution.
Would a route-based VPN between the two sites (each has an SRX240) allow seamless communication between the clients and the PBX? Is NAT involved in anyway? I've had bad experience with NAT and SIP and I'd like to avoid it. Iplan to create one st0 in each site and put them at each side's trusted zones.
Site A will only export the subnet of the PBX and site B will only export the subnet of the clients.