UCM 8.0 - Maximum Calls Per SIP Trunk

[Kirill Klimakhin]

Hello everyone,

I have looked everywhere but do not see a specific number that states how many SIP calls can be placed on each SIP trunk configured in the UCM.

I know it's bandwidth dependent but is there a physical limit specified for the UCM?

I am planning for SIP integration with a ACD system and I am being asked to give them a maximum number for each configured SIP trunk.

I am running UCM 8.6 on UCS C210 servers.

Thanks!

[james.ferris · Accepted solution]

I dont think there is a hard number.  According to the CUCM data sheet CUCM can handle a maximum of 100,000 busy-hour call completions (BHCCs) per Cisco Unified Communications Manager server and 250,000 per server cluster (configuration dependent)

For SIP trunks as you mentioned bandwith is one of the factors along with CPU usage, available memory, weather or not  this SIP intergration requires MTP, what codec is being used, transcoding, etc. 

Is the SIP trunk terminated on the CUCM or are you using a voice gateway with CUBE? 

You have more controll if your using  a VG and CUBE.  For example you can use the max-conn under a dial peer to specify the max number of connections.

Or you can use the call threshold global commands to limit calls based on resources available.

[Chris Deren]

Correct, SIP trunk is just a virtual connection and no limit exists, you will be limited by CUCM server limitations and/or CUBE session limitations.

HTH,

Chris