Fine Tuning of MS Proxy Server 2.0

I am having MS Proxy Server 2.0 in my office
with 64 Kbs ISDN Link. Every day 25 peoples
(Average)are browsing the net through that
server. When I reboot the server and reconnect the ISDN for some reasons, the
clients are not getting the browing imtly(atleast after 30 mints), the errors “Host was not Found” or “Software Caused connection to abort” coming after the 1 or 2
hour only the people are able to browse. Even
though i am having the P3 with 128Mb RAM Server and 1Gb chaching i am able to work with this MS Proxy…. If any one could help..it will be very usefull for me

thanks
anantharaman v