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JTAPI Application Design

Level 1
Level 1

Hello All - I am trying to build a JTAPI application and need some inputs for the design . My application is JTAPI softphone which sits inside a CRM, used to control users desk phone/Jabber. I would have a web server and application server hosting JTAPI.jar. This connects to CTI manager which is installed on a CUCM subscriber. My requirement is to scale up to 10,000 users

I see below from the guide.

  • Maximum Devices Per Provider-This parameter specifies the maximum number of devices that a single CTI application can open. The default specifies 2000 devices.

  • Maximum Devices Per Node-This parameter specifies the maximum number of devices that all CTI applications can open on any CTIManager node in the Cisco Unified Communications Manager system. The default specifies 800 devices.

If the configured limits are exceeded, CTI generates alarms, but the applications continue to operate with the extra devices. 


Now for my question(s): Does this mean I need to have 1 app server hosting JTAPI jar for every 800 observers ?(the guide says it would raise alarms if 800 limit is exceeded but will continue to function?) To solve this ,I am thinking of having multiple application instances having their own set of  CTI managers (Primary and failover, I anyway have 10+ subscribers in my environment)to cater to 10000 user base (In this case I would have 12 app instances (12*800 observers)). Is my understanding correct ? or is there a way to open multiple connections to different CTI manager nodes from same app server? or having a dedicated nodes running CTI manager service would help here with the scale?

Also, is there a general guidance on how the servers can be sized ?

Thanks for your help in anticipation!


1 Reply 1

Anusha B R
Cisco Employee
Cisco Employee


Have you had a chance to look at these documents -


Anusha B R