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CUCM 12.5 and Specific License Reservation

James Hawkins


I have a customer with CUCM 11.5 with only CUWL licenses installed. The users only have one device each so the license type consumed is Enhanced and CUCM borrows CUWL licenses to cover this.

When we upgrade to CUCM 12.5 we will have to use Specific License Registration (SLR) as the customer will not allow the CUCM Publisher to communicate with CSSM either directly or via an on-prem CSSM server.

My concern is whether using SLR with CUCM will allow licenses to be loaned between tiers as would be the case with this customer.

I upgraded UCCX for the same customer and specified Premium licenses when configuring SLR. This caused an issue as agents that were set up only for inbound voices required a Standard license and SLR licensing does not allow Premium licenses to be loaned to cover these logins - if the UCCX were configured to communicate with CSSM this loaning of licenses between tiers would be supported.

Has anyone set up SLR with CUCM? - if yes then does it allow loaning of licenses between tiers or is this limited in a similar way to how UCCX 12.5 works?

1 Accepted Solution
2 Replies 2

Thanks Jaime,


For anyone else browsing the thread it seems that SLR in CUCM does work in a similar way to how I observed it in UCCX - the relevant information is reproduced below:


License borrowing from a higher tier does not happen automatically when a Specific License Reservation is enabled on Unified Communications Manager. License Reservation has to be updated manually to the Unified Communications Manager license consumption/usage.

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