Sorry but I don’t get what you’re problem is. In the part of your text where you wrote about your problem there isn’t any clear definition of a problem, not as far as I can see anyway.
That's Normal.
you can integrate CUCM and CUC using SCCP & SIP protocol. And the SIP trunk you created between CUCM and CUC is for integration and call handling. CUCM use this SIP trunk to send/receive calls to/from CUC
If you assign an extension to CTI route point, you can have have a maximum calls and busy trigger as mentioned below.
if you assign the same on a phone below mentioned is the maximum your get. So we normally assign AA extension to a CTI and also another reason is to avoid consuming license. The AA will also work if you create just an extension with call forward all to VM.
This is normal as CUC does not have control over the CTI RP via CTI and it does not have any need to be in control of it. The important part of the configuration is the directory number that is forwarded to voicemail.
So your remaining problem is that you hear the message Wait while I transfer your call? If so @Nithin Eluvathingal already gave you the information on how to get rid of that, “uncheck the Play the Wait While I Transfer Your call Prompt option”.
On a side note, the polite thing would be to give appreciation to the people who helps you out by using the helpful vote option on posts before asking for more help on new questions.
