okay so for the past two weeks i haven't been able to connect to xbox live, i am currently using a 3G mobile broadband modem using a direct connection from my computer and then an ethernet to my xbox, which in the past has worked perfect for me, just to confirm that my ISP was not the cause of my problem i ahve contacted them and they have confirmed that all ports on my connection are infact open. Also i have checked and confirmed that all of my ICS settings are in fact all correct. The problem i am getting is that my console connects both to my network and the internet fine, but when it comes to connecting to xbox live it reaches a 1/3 of the way to connecting then just goes back and forth until it eventually fails and i get the error message that it cannot connect to the xbox live service, on the few occasions that i have managed to connect i am disconnected either instantly or within roughly 10 minutes of connecting (Also when i try to reconnect i have the error that there was a problem signing in as my console cannot contact the xbox live service.) After 2 weeks of frustration and trawling through many forums to try and come to some sort of conclusion as to what my problem could be, i thought it may be the ethernet connection on my console, but now know this is not the case as my xbox is currently connected to xbox live and running perfectly fine at my girlfriends house. I then thought it could possibly be the port on my computer but now i am unsure as why would my xbox connect to both my network and the internet in the first place if my port was to blame. I have also thought i could possibly have a dodgy ethernet cable but i know this also not the case as i do have 2 ethernet cables which i have tested and know that they both work fine. Also notably i have been recieving on many occasions the IP 169.254.x.x which i know is an error in my console being able to make any sort of connection service with my LAN have also tried to use static IP connections.). If somebody could please shed some light on this ridiculous and annoying situation i would much appreciate it, as you can see i have done my research on this and have still come to no avail so i'm getting very frustrated with it now because i really want my xbox live back :( anybody that has any sort of input or could in fact help me solve this situation please reply and get me back on to xbox live because i am going crazy here trying to figure out as to what the cause of this could be.
Thank you in advance to anybody that actually takes the time to read this and/or replies.