I am getting stressed

 This damn XBOX360 or Rainbow Six Vegas or Router.  I really don't know the problem. It is one of the three or maybe a combo of all. 

Me and my clan have noticed when some people host some members cant get in, some cant, hear another member in the lobby or game. Lately it has been getting this way for me. 

Last night, I could not connect to the dedicated server that we usually always play on. I tried and tried. The members in the lobby were sending invites and every time I accepted, it told me (Failed to join requested match).

I done all I could think of. Reset my XBOX, Router, Computer. Checked all my settings. My NAT settings were open ( according to XBOX, Microsoft, & Dlink this was the optimal setting). I have an XBOX live compatible Router according to the list on xbox.com.  Trying to get any sort of customer support is like driving from coast to coast on a moped. It can be done but it will take forever.

I don't know what to do. Is there anyone out there that has this same problem.

I might have to buy a better router. I don't want to do that unless I know for sure it will fix the problem.