Have read various entries on this across the forum but cannot find an straight answer. Maybe I have missed something. I have an HP Proliant DL360 G6 running SBS 2008. All fine. 3CX v8 was running on an old Dell box with a single NIC. Thats been fine as well. Created a backup of the config on the Dell and restored this to the HP box making sure the installer I used for 3CX was identical. Dell IP address I created on the 2nd NIC on the HP. Created my routing table to point all requests for the SIP trunk to point at the correct router. Only one G/W is featured on one NIC. The other has none. In the "wrong" router I have put a route sending traffic to the SIP router. Proved all this to work with trace & ping tests. Disconnected Dell & started 3CX on HP. SIP trunks register & outbound calls no problem. Nightservice routes inbound calls to voicemail. This works no problem. Day service - inbound calls fail. Looks show that the call routing is trying to present a call to the ring group from the wrong NIC IP. Clearly this is why they are failing. Have ensured the STUN server is off & that I have enetred the ISP IP & the correct NIC selected. Ensured that in the "advanced" tab all the IPs relevent are correct. Not sure now what else to check? I have rolled back my config to the Dell so service is working. I am guessing therer is an answer to this judging by posts on here. Any ideas? Thanks!