Problems with Facetime

I'm a macbook pro user...I found out that my FaceTime quite funny..whenever i FaceTime with my friend who is also a FaceTime user with his macbook...we cannot chat long because the FaceTime seems to be hang there and my whole macbook will just hang also...but...when I call my friend to his iPhone FaceTime ...it doesn't has this problem at all...we even can chat for so many hours...is this my macbook problem or is his problem?

I went ahead and changed your thread title. A good thread title helps draw interest to your question.

As to your question - you may want to have a look here:

Apple - Support - FaceTime - Troubleshooting

...and also here...

Basic Mac Troubleshooting | Mac-Forums Blog

...and let us know how you make out.

If you got it from the app store then you can uninstall the app and then redownload it and see if it solves your problem.