I'm having the same issue: constant poor connections, video/audio freezing, reconnecting, and failed FaceTime calls. I only FaceTime with one person, but because we've grown so accustomed to this type of call, it's very annoying now that it constantly doesn't work.
- My wi-fi network is entirely Apple (2 Airport Extremes).
- The friend I FaceTime with has a NetGear wireless router at his home.
- At his mom's house, I have set up an all Apple wireless network (again, 2 AEs).
Before the official release, I had the iOS 6 beta and he had iOS 5, and the problem occurred then as well. At that time I thought the problem was only occurring because of changes in iOS6 and expected the problem to be resolved once we were both on iOS 6. It was annoying, but I didn't think much of it. Now, we are both on the official iOS6 release, and obviously, as everyone here has noticed, the issue is not resolved.
I have reset my iPhone 4S's network settings and it has no effect. Two nights ago, he reset his network settings, and FaceTime worked for the following call over the NetGear router. Yesterday afternoon, he called from his mom's house on the Apple network and the call was fine. Yesterday evening, back at his house with the NetGear wireless router, the problem returned. He reset his network settings again, and it again worked for the following call. I can't find any real pattern for the problem except that it seems to originate from his end, when the NetGear router is involved. Then once it starts, based on experience from many past calls, it doesn't matter whether he is on his NetGear network or his mom's Apple network. So it seems to be related to some persistent hidden setting on the phone that occurs as a result of the connection to the NetGear router, which doesn't occur until the second connection to it after the network settings reset, but that seems ridiculous to me. What kinds of routers do most of you having this problem, and the person with whom you are FaceTiming, use?
On another note, does anyone know what the network settings change to DNS 8.8.8.8 is supposed to accomplish? This is a Google Public DNS server. Is it expected to resolve something correctly that my ISP's DNS servers won't?