Obtain low bandwidh in linux. I m using a Redhat linux AS 4 proxy server in my office,in which I

Question

I m using a Redhat linux AS 4 proxy server in my office,in which I configure squid 2.5 for sharing the internet(BSNL dataone leased line).the band width provided by the ISP is 2 mbps,but when I check the bandwidth in http://dataone.in from the proxy server it shows around 400 kbps.then I connect a dual boot client pc ( windows XP sp2/fedora 6) to the same port I use for the proxy server in NORTEL 8300 switch.Now I got the increased bandwidth (around 1.77 mbps) in XP but again low bandwidh with fedora. plz tell me why linux operating system show me the low bandwidth ?