I have ccm 5.1.3 in my vmware lab.
I created cti RP for ARC. I have also associated the ARc user with the CTI RP.
However the strange thing is that immediately I crreate the cti rp, it picks up the ip add of the callmanager rather than registering using the ip address of the ARC server.
I also created cti ports on calllmanager and they all register using the ip add of the ARC server.
I have restarted the cti manager but I got the same thing.
Ideally, the cti rp should register with the ip address of the arc server