Hi, It's very useful feature, avg.gentime factor.
Is it possible in page - individual access(IP) - menu or some DB query?
I want to check gentime(network time+response time) from various country.
Yes it's possible to get this data in the Page URLs widget, see also: http://piwik.org/docs/page-speed/
For further question feel free to ask in the forums: http://forum.piwik.org/