Line/extension state query on a distant IPpbx SIP subscribe through a trunk


I wondering if there is a way for Asterisk to subscribe through a SIP trunk to the state of line/extension on a remote IPpbx like a Cisco CUCM.

I have all my phone devices registered on a Cisco CUCM cluster and I use Asterisk for ACD purpose but I cannot get the extensions state on the remote IPpbx.

Thank you for a response.

This is not currently supported by either chan_sip or chan_pjsip.

Is it planned in a future release?

Asterisk is an open source project. What exists is based on what people contribute and what they like/need to work on. I know of noone working on such a thing.