Configuring for Client/Server

Applies to: All client/server configurations

The following was posted on the Apollo Server news group by Andy Duggan:

I have an application that is running between 3 states via a VPN. I had a nasty little problem where the application would start (connect to ADS, Login to ADS) and then would hang. I also had another connection (via Internal ISDN LAN to LAN Routers). That connection worked.

I remembered someone saying they had problems with Firewalls. At the same time, one of my connections could not receive e-mail from 3 particular companies around worldwide. I reported this to the ISP and asked about their Fragmentation rules. They had the MTU setting on one state set very low. This setting for the VPN and the fact that the routers were running behind a NAT box were causing the problem.

To explain in easier terms, the default MTU size for Windows 98 is 1500. If a packet is larger then this it will be fragmented. Our ISP had set the MTU to 576, which too small. When the MTU was set back to 1500 the problem disappeared. In summary, running Windows 98 requires the MTU to be set to 1500 in order for proper data transmission over the Internet.

Additional resources

(Courtesy of Darryl S.) After doing research on the following links, I increased my cable modems download speed by a factor of 5 on a poorly optimized computer. It was around 60KB/s and now is around 300+KB/s.

• http://homepage.ntlworld.com/robin.d.h.walker/cmtips.html#homelan
• http://www.speedguide.net/editorials/packet_size.shtml
• http://www.the-scream.co.uk/html/resources/adsltips.html
• A small utility to make registry changes for you:
  http://www.dslreports.com/front/drtcp.html