Internet speed constantly up and down

[plcman]

Hi

I have an issue on a server with SBS2003. I consider myself pretty computer literate but am no SBS expert.

Basically the internet speed seems to be being slowed down inside the server on a random basis. I have a 2 NIC setup with one NIC connectd to a broadband router, I get a connection speed on a laptop plugged directly into the router of 6mb. The server and work stations though sometimes have 6mb but more often have speeds less than dialup.

It has been a real pig trying to get to the bottom of this and so far I have had the telecom line changed to raise the incoming connection from 1mb to 6mb, I had all the telecom internal wiring and filters changed. I have checked all of the CAT5 cableing. I have worked across weekends to try and find a reason but 9.5 times out of 10 the speed is good at night and at weekends.

I am at a loss of what to look at next so any advice on a path to take to find the route of this random problem would be gratefully recieved.

 

[Chuckak]

Is your Internet connection a DSL line. If it is you likely have an MTU issue. Default is 1500 on server 2003 and XP. DSLreports.com has test section that will help you verify the issue. You will need to set the MTU in the router to a lower number (found by testing) that has the external connection to the DSL line. You can just set it to 1425 and test to see if the issue is resolved. If it is you can use the ping tests to find the maximum number then set your router to it. You might find improvement by setting the XP workstation MTU to the same value using the DRTCP utility.

 

[ShackDaddy]

So all the workstation internet traffic is routed through your server before it gets to the router? I think checking the MTU at the server is the best initial idea. Are you running ISA? If you aren't, then I would consider not using a dual-NIC arrangement at all and see if your workstations start doing way better when they communicate directly with the router. SBS 2008 and SBS 2011 don't even support that configuration anymore.

Dave Shackelford
ThirdTier.net
TrainSignal.com

 

[markdmac]

Look for users running Pandora or other streaming media.

I hope that helps.

Regards,

Mark

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