iMac FaceTime freezing and quitting after a few minutes of connection

Mid 2011 iMac with Yosemite 10.10.2 places FaceTime call but the recipient reports that the video freezes and audio is lost after a 5-10 minutes. When I try to recall her she does not receive any indication. When she calls me, I cannot connect on the iMac, but I can on my iPhone 6. Any suggestions welcome.

An Update

Installed WiFi explorer and identified a number of wifi networks using the same 2.4 GHz channel. Switched channel on my Time Capsule to 5GHz and the problem has not recurred.

WiFI loss in FaceTime

I've a mid 2011 iMac which recently began losing FaceTime connections about 15 minutes into a call.

Welcome to the forums! What recently changed on your system or with your ISP? If it's consistently dropping at the same point for EVERY FaceTime, I would be suspicious of your ISP doing something. Does it also drop if you try FaceTime on a different network?

Thank you for your reply. I do not believe it is my ISP as I am able to use Face Time without interruption on my iPhone, iPad, and MacBook Pro. The interruption is not always at 15 minutes, it sometimes occurs earlier, sometimes later. I spoke with Apple Support last evening and they help me clean the FaceTime cache in the library. I am testing the results of that process this evening.

Ah, you hadn't shared that all the other devices were working just fine. Hard to diagnose with only partial information. Glad Apple was able to help. Good luck with it!

Resolution

I reinstalled the operating system at the behest of Apple Support and the problem seems to have cleared up.