Debian is slow on the Network

[<nicolas.kosmalski@alemtid.asso.fr>]

Hi,

i have little problem with my network speed. (i dont know how do we say
exactly in english).
I explained my trouble :

I use a java application on a window computer, which do a request to my
debian computer; the time to give an answer is nearly the 25sec. It's
the same thing if i do the request from all the computer to my debian.
But if i do the request to another computer it's fast!

The time to show a prompt for a telnet to my computer is long too but
(near 5 sec.)

The ping is classic to the window computer (~0.30 ms).

I am a alone debian on a LAN composed by a lot of windows and one AIX.

I saw on the web that it could be a host name resolution problem. but i
dont think so. (the host name resolution is fast when i connect to a
website).

The problem is essentially on the local, the internet connection seems to
go well.

i dont see exactly where is the problem, maybe the network, but it seems
only the network for  my computer that is so slow.
Configuration tips? idea? i take all !

thanks