Please try adding the following permission to the user in callmanager
Standard CCM End User Standard CTI Enabled Standard CTI Allow Control of Phones supporting Connected Xfer and conf Role Standard CTI Allow Control of Phones supporting Rollover Mode
Also please make sure first if the user is able to control other IP Phones so that to ensure there is not other issues other than the phone model.
They can control other IP Phone models. The issue is if they use the 8945 and they get an outside call and try to answer it, it disconnects the caller if the presence client is running.
That is a bit strange behavior. Please replication as much config as possible between a working IP Phone model and a 8945 IP Phone (including phone load as much close as possible) and see if the behavior replicates. I suspect this might a config/call routing issue on cucm.
The codebase on the 8945 is based on 6921/41/61 phones, which require the additional roles that MD has pointed out in order to control properly from CUPC.
Have you tried any 69xx phones? Have you tried adding the roles that Md has suggested?
I took a look and found other customers have had success with controlling 8945 devices are adding those roles.
What version of CUPS, CUPC, and CUCM are you running?
I already did. I was told since that model isn't listed as being supported with the current release, I would have to wait till a update came out that did list that model as a supported device in CUPC.