I used MSN to start converation with the machine within the same institute's network. It worked greatly without any problem.
When I used it with my friend in another state within USA, it never works.
When I used it with my parent in China, it worked for about severak weeks only at the beginning when my parent switched to a New Phone Company. after about one month, it stopped and not work any more. Right now we can only see each other and can not talk any more.
There is no pronlem in the related hardware and software setting.If you have any solution, I will be more than happy to listen.