Problem with lan

[Pitsilkas Manolis]

I have this problem with my lan al home:I have 3 PCs.All have network cards 10/100.My switch is at 10/100.Although i can't get more speed than 25mbit/sec.I have tried with several cables(handmade and from stores) but nothing.What could be the problem?

[Jim Mallett]

There will be a little bit of overhead anyways so it'll be hard getting the full 100MB performance, but you should be doing much better.
There are quite a few things it could be but I would start with these:
Check that you are using the TCP/IP protocol. Unless you NEED them, remove any protocols that are not being used (ie: NetBeui).
Check the configuration on the network cards and see what the link speed and duplex settings are. I normally keep mine at "Auto" for auto negotiate, you could try forcing 100MB Full Duplex though and see if that helps.

Jim

[Ernest Ford]

What are you using to measure the transfer speeds?

If you are measuring the time it takes to transfer files, you are including several other factors in the test which can impact throughput negatively.

[Schnellmann]

As Ernest stated it's the way of measuring the transmission speed. If you try with ftp to test the speed you have to keep in mind that the window size as well as the packet size is affecting the transfer (acknowledgment of the received packets).

[Schnellmann]

As Ernest stated it's the way of measuring the transmission speed. If you try with ftp to test the speed you have to keep in mind that the window size as well as the packet size is affecting the transfer (acknowledgment of the received packets).

[Saad_1]

Hi, I can help you tweak your TCP/IP stack to get a few Mbps more out of your existing network. But it depends on whether you are willing to edit some registry settings (I am assuming you are running windows)
I reccomend that you use 'iperf' to measure the transfer speed. Find out what packet size get you the max out of the network. ( http://dast.nlanr.net/Projects/Iperf/ ). Once you get the readings, post a summary or mail me on my private address. I will then send you the appropriate changes to be made to windows registry. Just as a info note, I manage upto 93Mbps on a LAN between two laptops using the iperf test, thats getting a LOT out of windows XP. THe registry fix also improves downlaod speed if you have high end broadband connection.