Hello Dear Amos: I guess i know real reason via analying request and rep header of firebug . i found our cache obtained data from other cache(not us ) , and Age is small value or 0 , So our cache have to refresh or confirm with other cache often . and we i found waiting time is very high via monitor some hit objects . Whether we can increase age value via squid config ? Thanks for your advisement _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users