Sip trunk to CUCM

[Juraj Papic]

Hi all,

I would like to know in what scenarios I have to configure a SIP trunk from the CUCM to the Presence?

thanks. 

[Roger Kallberg]

Not 100% sure, but if memory serve me it's required for any systems from 8.5 and higher. Can't find a document to back that right now, but there is for sure mentioned in various Cisco doc.

[Juraj Papic]

Im asking this because I have a customer with a CUCM and IM working and there is no SIP trunk configured.

thanks.

[Roger Kallberg]

The trunk in itself is not used for IM. It’s use is for presence information, like On a call.

[Roger Kallberg · Accepted solution]

From the configuration guide for CUPS.

Configure SIP Publish Trunk on IM and Presence Service

When you turn on this setting, Cisco Cisco Unified Communications Manager publishes phone presence for all line appearances that are associated with users licensed on Cisco Unified Communications Manager for IM and Presence Service.

This procedure is the same operation as assigning a SIP trunk as the CUP PUBLISH trunk in Cisco Cisco Unified Communications Manager service parameters.

[Juraj Papic]

Thanks!!!