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Passing Line status over trunks

Level 1
Level 1

I have 2 CUCM 7.15 clusters. They are connected via a “Inter-Cluster Trunk (Non-Gatekeeper Controlled)”. Calls and caller ID pass between them just fine.

Phones in one cluster can see the line status of other phones in the same cluster when I check missed calls, placed calls, corp directory, etc.

I am trying to get the line status in the corporate directory to display for ALL phones, including the phones in the other cluster. Is this possible? I do not see a “SUBSCRIBE Calling Search Space ” field on a “Inter-Cluster Trunk (Non-Gatekeeper Controlled)” – but I do on a SIP truck.

Do I need a SIP trunk to pass presence (line status) information? If so, I assume I can ditch the old trunk and just use SIP for both calls and line status? Would this also allow the Attendant console to see line status of phones in the other cluster?  All phones are currently listed in the corporate directory.

Am I barking up the right tree? Any advice\pointers would be greatly appreciated.

5 Replies 5

Level 1
Level 1

...selfish bump...

You could try using SIP trunk for the integration instead of H323 ICT, but I am not sure if the presence state will be delivered accross it, worth a try.


Try to use a SIP trunk like Chris said, take a look on CUCM SRND to unterstand the concept.

"If the presence entity exists outside the cluster, Unified CM will query the external presence entity

through the SIP trunk. If the watcher has permission to monitor the external presence entity based on the

SUBSCRIBE calling search space and presence group (both described in the section on Unified CM

Presence Policy, page 23-9), the SIP trunk will forward the presence request to the external presence

entity, await the presence response from the external presence entity, and return the current presence

status to the watcher."


Leonardo Santana

*** Rate All Helpful Responses***

Thanks for the replies.

I saw that in the SRND, but thanks for posting it.  I guess it's confusing a bit because "presence" is a term used when maybe it shouldn't.  My understanding is when you see the line status in the corp directory, it's often referred to as "BLF For Call Lists", and not "Presence" since you're only seeing the line status.  So it's sometimes hard to understand when the SRND referrs to "Presence", if it's also referring to the directory, or just the product called "Presence", "Jabber", CUPC, etc.

BLF is presence.