cloudfront cdn report 48+% packet lost

I noticed bitbucket start using cloudfront as a cdn solution. And I been having trouble since then.

Turn out couldfront been giving 48+% packet lost. So it is causing the web page can't fully loaded:

{{{
ping cdn.bitbucket.org -t
Pinging d2aq0a746ftmav.nrt4.cloudfront.net [216.137.53.244] with 32 bytes of data:
...
...
Ping statistics for 216.137.53.22:
Packets: Sent = 587, Received = 302, Lost = 285 (48% loss),
Approximate round trip times in milli-seconds:
Minimum = 124ms, Maximum = 287ms, Average = 160ms
}}}

I'm from Shanghai China