Increasing parameter "maximum number of registered devices" on CUCM

[raghav0122]

Will there be any impact on increasing maximum number of registered phones on the CUCM subscribers? CUCM 12.5

[Nithin Eluvathingal]

Not clear what you are looking for? could you please explain a little more about your question. 

[raghav0122]

It is the service parameter on each subscriber, where the maximum number of registered device is 5000 which is set by default. We want to increase that number 10000. So, want to make sure if there will be any impact if we change that value.

[Nithin Eluvathingal]

Unified CM Capacity Planning Guidelines and Endpoint Limits

The following capacity guidelines apply to Cisco Unified CM as part of Cisco Business Edition 7000 or outside of Business Edition:

• Within a cluster, a maximum of 8 call processing subscriber nodes can be enabled with the Cisco CallManager Service. Other server nodes may be used for more dedicated functions such as publisher, TFTP subscribers, and media resources subscribers.
• Each Unified CM node can support registration for a maximum of 10,000 secured or unsecured SCCP or SIP endpoints. Each cluster can support configuration and registration for a maximum of 40,000 secured or unsecured SCCP or SIP endpoints.
• There are several VM configuration options for Cisco Unified CM available in the OVA, depending on the required capacity. The names of the VM configurations correspond to the maximum number of users per node, assuming that each user has one phone. When the ratio of number phones per user is different than one, the VM configuration names actually correspond to the maximum number of endpoints per node. Depending on different variables such as BHCA and feature set used, the actual number of users or endpoints could be lower. To validate the sizing of a deployment, use the Cisco Collaboration Sizing Tool, available at https://www.cisco.com/go/cst .

But I Hope you have selected OVA accordingly to support 10000 devices. 

ReferSolution Reference Network Designs and Go through Capacity Planning for Call Processing

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/srnd/collab12/collab12/callpros.html#98004

[raghav0122]

Thanks for the details.

Sorry, I should have included this on my first post

We are on CUCM 12.5 and we have 10000 devices OVA used on all our subscribers.

My concern is, will there be any impact if I change the service parameter " Maximum number of registered devices" from 5000(default) to 10000 on a subscriber.

[Nithin Eluvathingal · Accepted solution]

No. You can change.

Make sure you use 1:1 redundancy.

[Roger Kallberg · Accepted solution]

As long as your VM are sized according there will not be any impact by changing this parameter.