hi!
after i install and configure squid as a transparent proxy i can see the different and that increase the speed of the net, but after one week it is not fast as first , how can i increase the speed again ??
thank you

The "speed increase" is perceived, relative, so if you cache items one week you need a lot and the next week only access unique items that need to be retrieved (MISS) you will not see any speedups. Squid works best with a large chunk of memory since caching in RAM is n times faster compared to disk (I/O) so for instance browsing workstation + proxy being one and the same machine isn't the most performant setup. There's more than this but the essence is it's hard to say without details and statistics. Have a look at Onlamp's Eleven Metrics to Monitor for a Happy and Healthy Squid and the http://wiki.squid-cache.org/SquidFaq. Worth reading.

ok, thank you i'll check that
thank you

Also you could check how often you cache is been deleted and how large your cache is

how can i check how often is mt cache and how to increase it,
thank you mahmoud ...

anyone has an idea ??