I am now in South Korea, which is reported to have the fastest internet. (It is kind of true, as it is quite easy for me to get a first post or get in a packed Hangout1 on Google+. If this seems to be an ad for Google+, feel free to edit it out.)
The thing is, with this seemingly fast internet connection, I cannot have a fluent video chat with my friends in China, Japan, United Kingdom and United States.
Now I deal with it by dialing a VPN, and after this, the video chats (including 10 people's Hangout) become fluent.
I want to know where the problem lies, and how to deal with it. I do not like to dial VPN so often anyway.
1: Hangout is a group video chat for at most 10 people.
Best Answer
A "Fast" internet connection does not necessarily indicate low latency, which is the most important factor in any real-time collaboration whether it be voice or video chat. Latency and bandwidth are two completely different beasts. This is why most corporate implementations of IP phones will make use of a prioritized "voice VLAN" to ensure calls are prioritized over regular LAN traffic. You can have a dedicated 50Mb connection and still have a choppy video chat with someone across the world. Give PingTest a try, see your results when running tests between the locations you've listed.
You may have a low latency connection to the VPN, and the VPN may have a better route to your friend's chat servers. The bottleneck could be between your ISP and the Google servers. A basic traceroute goes a long way in indicating bottlenecks between hops.