We currently have CUCM cluster with around 10,000+ users.
We are planning to add a new CUCM Subscriber to our exising Production environment.
This new sub will not run a CM service and only for IPVMS purpose.
I have read somewhere in the forum that during the installation of Sub, there will be a reset in all phones?
I just want to verify if this is still happening in 11.5 version as we want to avoid an impact,eventhough we will done during maintenance window.
Our CUCM version is 11.5 SU(5)
Thanks & Regards,
The reset of the phones, upon adding a Subscriber is an expected behavior, you can have a look below:
Thanks for reply.
When does the restart of the phones happens? Is it during the installation?
Is it apply to all subscriber? I just curious as I won't add Subscriber to CUCM Group as it's only run IPVMS.
If i remember correct, the restart occurs at the phones that below on the CM Group that includes the New Subscriber and its a soft-restart, ie if a phone is on a call, this phone will restart only when the call ends.
All the phones at this CM Group will restart, since the Publisher will send a restart prompt to the phones, to get updated with the new ITL file that includes -amongst other- info for the new Sub.
The phone reset has nothing to do with the CUCM configuration itself but rather updates to the ITL files when new node joins the cluster. Phones will reboot during the CUCM sub install process, so be ready for the phones to reset and plan accordingly.
Chris is totally right, I was going to mention that my previous comment was not totally correct.
Chris thank you for clarifying.
Just as a point of reference this was introduced in CUCM 8.5 or 8.6, in prior versions you were able to add CUCM node with no impact to the cluster (good ole days :0)
I would suggest to do it off hours.