Xbox live modem connection?

I hav my 360 connected to my modem which is then connected to the phone socket. i got my 360 with a 1 month trial on xbox LIVE gold. i created a profile on my xbox and have been obtaining achievements since i got it. i decided to get xbox LIVE and so got a long enough ethenet cable and connected it. Heres the problem. wen i go on the Live banner on the xbox dashbord and go on join xbox live it says my network connection failed. if i go on troubleshoot it all confirms except the xbox live part which says its failed and when i retry same thing happens. PLEASE HELP!!!!!!!!!!!

Xbox live modem connection?

i have mine setup to my modem.i would tell u word 4 word but u just go here read directions cus this is whrere i learned.http://www.xbox.com/en-US/support/connec...