Networking a military field unit overseas

I'm a member of the military currently stationed in Iraq and have been tasked with improving our current Internet situation for the 140+ soldiers here. I am somewhat familiar with networking, but I'm searching for some advice.

We "inherited" a 1.2m satellite dish that gives us 1024Kbps download speed and 512Kbps upload. The contention ratio is 10:1 with 29 private IP addresses. The satellite feed is plugged into a Linkstar ViaSat (TX Out & RX In); there is one cable coming out of the 10/100 Base-T. I believe that is plugged into an 8-port Nway Switch manufactured by Encore Electronics.

From the switch there are two cables: One that runs to a UDgateway device and another that runs to a D-Link Ethernet Broadband Router (4-port DI-604). I have unplugged everything attached to this router and now have Internet service with only three Ethernet cables running out of the router. Two of the Ethernet cables are directly attached to PCs running Microsoft XP, and the other cable is attached to an 8-port 10/100Mbps Ethernet switch. That switch is servicing four additional PCs.

The problem: We have zero Internet access because the previous unit had daisy-chained a bunch of Ethernet hubs attempting to service 26 trailers (78 rooms).

With the current configuration, how do I optimize the network to allow all soldiers to get Internet access in their rooms? Is there more gear I can add or is trying to provide Internet service to 78 rooms out of the question?

Please consider this a 140+ "employee" Army Field Artillery Company with network issues. Approximately 40 to 50 personnel could be utilizing the Internet at any given moment.

- A member of our military serving overseas

When I first started reading your message, my initial thought was to suggest some type of proxy server that could help prefetch repeated requests and keep some so-not-frequent ones at hand locally so your Internet connection could be kept free for other requests. After doing some research on the different devices you mentioned, I realized you already had something similar to that in the UDgateway device. I found more information on that device here. To get everyone to use this device, there may be an automated way of pushing out the settings that will be needed on their computers or you may have to visit each computer and make those changes.

I think your Internet access problem was twofold - it would appear that you had more devices going through the D-Link router than it was designed to handle. The other part of your problem was that cascading Ethernet hubs can present a challenge after a while when you start having an ever-increasing amount of Ethernet collisions and more demand for bandwidth than you can provide.

After looking at the UDgateway documentation, see if it can provide the "firewall"-type functionality that the D-Link device was. If it can, you can take D-Link out of the picture. If not, see if you can acquire a firewall device that can handle the number of computers you're trying to provide service for. There are some CD-based Linux firewalls that might be able to do the trick. Go to sourceforge.net, and you should be able to find some candidates there.