Calls from CUCM IP Phone to Asterisk PSTN


We have CUCM 8.6 and wish to have IP Phones registered with CUCM to make some calls using Asterisk connected to an analog gateway.

I already know that we will need to setup a SIP trunk between CUCM and Asterisk. When this is done what I need to do is allow IP Phones registered with CUCM to be able to make some toll free calls using a certain pattern to be routed through this trunk out to the analog line.

What is the configuration needed to accomplish this? Also what will be the maximum number of simultaneous calls that can be done using this scenario? What are the suggested PSTN card models I should use to have a t least two simultaneous calls to PSTN in the above manner?

Sorry for all the questions but I am sure this is the best community to get the correct information.


For the SIP Trunk definition on Asterisk side you need to define a SIP peer in sip.conf. You can run many concurrent calls through that SIP trunks. If you want, you can also limit the number of concurrent channels on the SIP peer.

We are a good peer support, but this still does not mean that we will do the work of learning the basics of asterisk for you. For a start read: