Question: How do I setup a remote extension to the UCM6100 series IPPBX?

If the UCM is using an external IP (not behind a NAT), then you don’t need to configure anything for remote extensions, but if it is behind a NAT then these are the steps:

- Navigate to PBX-->SIP Settings-->NAT on the UCM6100's web UI. Put the external IP of the network in the field “External IP Address” (if a domain is being used instead. e.g. DDNS, then use the next field “External Host”) and the internal IP of the UCM in the field “Local Network Address”
- Port forward in your router the SIP port for the UCM (by default UDP:5060 and can be changed under the “PBX” > “SIP Settings” > “General” tab –we recommend changing it to increase security) and the audio ports (by default the range UDP:10000-20000 and can be changed/decrease under the “PBX” > “Internal Options” > “RTP Settings” tab – we recommend decreasing it to 10000-11000).
- On the remote phone(s) use the external/public IP of the UCM as the SIP server. Also put in the SIP User ID, Authenticate ID, SIP Password for the remote extension.
- On the remote phones you may want to enable “Keep-Alive” for NAT settings. In Grandstream phones the option is “Auto” for the setting “NAT Traversal” located under the “Accounts” > “Accounts #” > “Network Settings” tab of the phone’s Web interface. If those options do not work then select “STUN” and put “” in the field “STUN Server” located under the “Settings” > “General Settings” tab also of the phone’s Web interface.
- On the phone(s) you may want to enable “Use Random Port” by setting it to “Yes” under the “Settings” > “General Settings” tab of the phone’s Web interface. For this setting you need to reboot the phone to take effect.

Category: UCM6100 Series