I'm not an expert on this, but I have cable, and I don't have to put a user name, or PW.
At my grandfathers house (He has DSL) I had to put in his full name, such as
Grandfather@aol.com (He doesn't have AOL, just an example) and had to put in his password for it to work, it took me a few days to figure that out cause the DSL company, and sony was saying you shouldn't need the user name and PW. It also had to be the main account holders name a PW. Also there was something about if he had a Dynamic, or Static IP, If I remember right I figured out he had a Dynamic IP. I don't really remember if that is what determined if I needed to put the Name, or not, but it had something to do with getting it to connect. Hope this helps some.
As far as have to user a router, I don't know about that, but I was using one at his house, and I use one at my house as well. 7seals seems pretty sure that is what it is going to take, so if all else fails give it a try.