See the CME admin guide:
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/admin/configuration/guide/cmeadm.pdf
You may need to configure translations/dial-peers etc. to setup the inbound/outbound calls.
See below for understanding dial-peers:
http://www.cisco.com/c/en/us/support/docs/voice/call-routing-dial-plans/14074-in-dial-peer-match.html
If you are still stuck, make a test call and post the debug of voip ccapi inout and also attach your show run.
-Terry
Please rate all helpful posts.