Thanks for your inquiry and apologies for the delayed response! You will need to log into an agent with Jabber before you can log into them as you've mentioned. Please let me know what Operating System you're running and I'll get you a copy of Cisco Jabber for Development and use in this lab.
I too am trying to test cisco uccx 10.5 via the sandbox and am unable to login as agent without the jabber client.
Could you please let me have a working link to download Jabber for Windows x64?
I've been trying to test out Finesse in the UCCX Sandbox, however I have been unable to log into Finesse.
When I try to log in with any agent, a message box appears stating "The device associated with that extension or dial number is invalid".
I found a forum thread here that discusses using the Cisco Jabber Client.
But, I'm unable to download it as it says I need a valid service contract.
Is the Cisco Jabber Client the software I need to allow logging into Finesse and make calls?
Also, is there a way to get the Jabber Client without a service contract?