Xbox live/router

Hi everyone,
My brother is having xbox live problems,when he signs in to xbox live it lags really hard,he cant join chat partys and cant connect to games,once every 100 attempts he can get into a game but then he as 1 red bar on the signal (1 red bar = worst,5 bars best).
He as an Edimax BR-6104K Router,his 2 pcs connected to the router via ethernet cables run fine,his xbox connected via ethernet cable is awful,when he connects the xbox 360 directly to his modem via ethernet it works perfect,
Xbox live tells you your NAT,his NAT says moderate.

can anyone help please,thanks.


p.s he cant wire xbox straight to modem as his girlfriend uses her pc at the same time

How much free space is on the hard drive of the XBox? This will matter, as a small amount of space will not let the hard drive work at its maximum function.

Thanks for replying here mate,but the matter is now solved
On xbox a moderate NAT only allows you to connect to certain people,
So he had to go in his router and turn on UPNP to make his NAT open
Now he is running fine
Thanks for the replys anyway mate
keep up the great work guys