I have a customer who already has a 3CX system and wants to connect it to an AT&T Business In a Box (BIB) SIP Trunk. I've seen some information on these forums about doing this, but the solutions mentioned made use of two NIC cards in the 3CX server. I would like to avoid that, if possible, and only use one NIC card in the 3CX server. The customer needs to keep all telephone traffic on the same network as his computer system (can't split telephone and data traffic into two networks). Since the data connection and the SIP connection are provided through two ethernet connections from AT&T's equipment, is it possible to use a dual-WAN router (such as a MikroTik router, programmed as such), to connect both connections (data and SIP/Voice) to the customer's LAN and the 3CX server (thus only using one NIC on the 3CX server)? If so, does anyone have some fairly specific information on how this might be configured? John Rayfield, Jr.