I am setting up a spare router in case my WAG54 dies at some later date. I have 2xVFX lines on an SPA2102 working fine through the WAG. The spare router is an SMX 7904WBRA2-AU which is ADSL2+ and says it is "voip compatible". Is there any settings I need to consider on the SMC router to get the 2102 working or does it look through the router in some way. I don't quite understand how the VFX communicates through the router with the WAN.