CUCM 11.5 Call Pickup group sizing

[sergiope]

We are in the middle of migrating an old PBX to a CUCM v11.5 cluster. Our end customer has requested us to place all these phones (10,000+ phones) into a single call pickup group to be able to pick up calls from a BLF Speed Dial.

My question here is, what would be the implications of doing this? If we were to apply this setup, would that have an impact on performance on our CUCM call processing nodes? Also, if there an actual size limitation for call pickup group members?

Thanks in advance! 

[Jaime Valencia]

I don't believe there's a hard limit for the maximum number of phones in a pickup group, but I'd exercise caution and would advice against doing that, you're going to create a signaling storm to 10K+ devices for every single call. I've never heard of anyone with such requirement to ring/alert 10K phones all at the same time for every single call.

Not precisely the same scenario, but read:

Performance and Scalability for Hunt Pilots

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/11_5_1/sysConfig/CUCM_BK_SE5DAF88_00_cucm-system-configuration-guide-1151/CUCM_BK_SE5DAF88_00_cucm-system-configuration-guide-1151_chapter_010101.html

I'd advise you reach out your SE to discuss this.

[Dennis Mink]

LOL,  has your customer actually thought about the implications of that?  

I would personally make them understand this is not a good thing to do and could potentially actually cost them money, when they have 10K employees trying to pick up a call every time a call comes in through the pickup group.