Couple of things:
1: It's Microsoft you were calling not "Xbox". Xbox is a product name.
2: At some point along the way you seem to have mixed up IP with ISP
3: Try some paragraph breaks next time
That all said, it sounds like they were going to have you open a port on the router, which really shouldn't be necessary.
Personally, I'd just run a google search for connecting the Xbox to Xbox Live, and every time you run across an error message, pop that into Google and see what you get as far as troubleshooting goes.
Ok, I've been having a lot of touble connecting my xbox to the internet. I've called Xbox, Linksys, and AT&T trying to figure the problem out. Here's the gist of it.
I got the xbox, plugged it into my router, ran a connection test and the DNS failed. I called xbox, they told me that I needed the DNS #'s from my ISP to enter it manually. I called my ISP got the #'s, entered them manually an it still failed. I called back xbox and they now had me connect the xbox directly into my computer. Did that and then the ISP part of the connection test failed. Xbox tells me to call my ISP and get my ISP address and the subnet mask from them. I call my ISP and get that info and they tell me that my router has changed the ISP because it doesn't start with 192. and that it is odd that it doesn't. But I use the numbers that I have and it still doesn't work. So I call xbox back, they tell me that I now need to call Linksys and have them open a port so that I can somehow connect it through that. So I call linksys and they now want to charge me $30 to tell me how to open a port but that first I need to call back xbox and get some #'s from them (I can't even remember the ones they want....by this time I am numbered out). I didn't pay Linksys and I didn't call back xbox for the numbers because the whole thing has me disgusted. It all sounds like a load of BS froma bunch of "techs" that don't really know what they're talking about and since all of the techs that I talked to (with the exception of the xbox people) don't speak english as a first language I am having a hard time understanding what they're talking about. So does anyone know what I can do to get connected? It just seems like a whole lot of BS to go through to get to xbox live. Any help would be greatly appreciated.