Configuration Verification

I believe I have a fairly rare situation. I own a wireless ISP in
Florida and operatite via a 2.4 Ghz wireless Metropolitan area network
(MAN). All of my customers have a wireless connection with 1.54Mbps of
Internet connectivity.

I have a 100Mbps link onto a OC12 for Internet connectivity, Here sets
my parent cache.

At each hopping station (We have a range of 10 miles from each hopping
station) I also have a linux box running squid. I also have several
customers running linux boxes with squid.

So presently my configuration is fairly simple:

Parent:
    All other cache boxes are listed as siblings

Siblings all point to the parent. When we go two hops down the line,
the parent for that would of course be the next cache (hop) up the line
toward the Internet POP.

My question is this, I have only had this set up for about 2 weeks and
have seen a significant reduction in the amount of Internet bandwidth
used. However I'm not totally convince that I have all of the boxes
tweaked for best performance. My stats on all of the siblings run about
a 50% hit rate, but the partent pulls 99% of all it's content directly
from the Internet.

I've also been unable to figure out how to change the configuration to
make a page fresh for 2 mins instead of 30 seconds.

Any and all help or comments are greatly appreciated.

--
Thomas Gaume                            *Wireless Networking experts
VP - Operations                         *High speed Internet access via our wireless MAN's
Airwire.net, Inc.                        (Metropolitan area networks)
407-752-4000, tom@airwire.net
http://www.airwire.net