CUCM publisher like backup for Call Processing

[cristian.munoz]

Hi All

I have a question of a customer, about of to use CUCM pub:

What would happen if you use CUCM pub as backup for Call Procesing in a cluster more than 1250 users?

There is some Cisco document about it?

TIA
Cristian

[GadgetFood]

Simply put... It would process those calls.
I was doing this when I was at a business that had more than 3000+ users, however all those 3000+ users are not processing call at the same time so keep that in mind for your environment.
I would recommend only to use Pub for configuration changes and not call processing.
I am not sure what your ratio your using but I would recommend setting up an additional subscriber node if you feel you need additional resources.
I am not sure which version your running but see the link Cisco SRND link
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab10/collab10/callpros.html