[solved] Usually showing "cannot display the web page"

[redstrike]

... The bottneck is the VPS provider limited my banwidth usage to 4 MB/s (normally my site used 6 MB/s), everything will be drop when it over the limit .

Thanks NiteWave, if you didn't find out that, i wouldn't know the situation. Adding more node for load balancing is my solution now.

[NiteWave]

while everything drop, CPU usage of litespeed process up to 100% -- so the reason is the bandwidth limit. this result will benefit other uesrs. Thanks for the feedback. I'd mark this thread "solved".