Goodmorning everyone. we are trying the free version of 3CX with a gateway Patton 4639. what we want to do is to associate a VoIP extension number to a specific port of Patton of which links 5 ISDN lines each with a different number. specifically: if the switchboard 3c are created 5 0001-0005 and Patton extensions are connected 5 ISDN lines with numbers from 1000 to 1005 we would like to associate the 0001 extension with the number isdn 1000 and so for the other four numbers. Is there anyone who can help me by explaining step by step how to do? thanks to everyone. I have to match the extension created in 3cx 0001 with the number isdn 1000 I connect to port 1 on the SmartNode 4639; I have to match the extension created in 3cx 0002 with the number isdn 2000 connect to port 2 on the link suggested smartnoe 4639.