Hi sijan,
Here is the link you were looking for, http://www.808.dk/?code-csharp-nas-performance . Also, 2.5 MB is dramatically faster than 400 kbs about 6x faster, but even transferring a bunch of small files, I would think you should be over 6 MB. Are you sure you have a switch and not an older hub? You might try making the connection to the NAS via one of the ports directly from the router and use a computer which is also connected to the router as a test and see what kind of transfer speed you get then. If you get another dramatic improvement, you can bet that there is something off on your switch. Anyway, good luck.