I have same scenario now, upgraded the application from 6.2 to 7.2 and configured the CTI link as well.
Able to connect to CTI and login to Pega call as well. When dial in as User and give account number details in IVR, call is getting connected and status is getting changed in Pega call. But Call pop up is not appearing and in trace i don't see any account number details except the caller number details.
I see that your post has 2 replies. Please address them stating if they helped you or if your requirements are different. That way the other community members would know and can try helping you better. Active engagement is the key!