Reason and behavior of IM&P and CTI in services profile

[Ali Amir]

Greetings,

In my lab I am playing with CUCM, IM&P and Unity.

In user profile configuration "Home Cluster" and "Enable User for Unified IM and Presence" > are enabled.

I already configured in IM&P Server the CUCM SIP trunk, presence gateway, TFTP Servers and CCMCIP.

By the mistake I didn't configure UC services and UC profile for the users. I mentioned that, without any configuration of IM&P and CTI as UC Service users can login to Jabber, They have IM and Presence functions and also use Jabbber softphone.
My test Agent can login to Finess and get calls on their Jabber/Finess webpage.

So, Do I need to configure IM&P and CTI in services profile for the users with above requirements. Can I ignore this part of configuration?

CUCM ver 12.5

PS:

I now for voicemail, I have to configure the related UC services and add it to related service profile.

I added two IMP Servers as UC services. It's not important which server is configured in service profile as primary. The Jabber client logged in to the IMP Server, that the user was assigned on it.

[Jonathan Schulenberg]

CTI is used for desk phone control when on-prem (Cloud Connected UC supports Borderless CTI for MRA connectivity). I’m a little surprised IM worked without an IM&P UC service assigned but I don’t understand the discovery process at that level of detail to explain why it worked without one. Maybe someone else will chime in with that tidbit.