Basically, Verizon DSL isn't like cable. Verizon DSL uses PPPoE, which uses a username and password to log onto the service. This can be done a number of ways. It can be set up in XP as a PPPoE connection natively. This creates a connection which you have to physically open and push connect each time you want to use it. There are many 3rd party PPPoE "dialers" as well, for earlier versions of Windows that did not support PPPoE connections.
The Westell modem, be it the Versalink or 2200 are capable of "dialing" or logging in with your username/password each time the modem is turned on.
Another option, if you don't have the Versalink (westell mode & wireless router ALL-IN-ONE), and you have the Westell 2200 is that you can use a router with it. MOST ROUTERS, like the Linksys WRT54G, can do PPPoE dialing (through the modem), but there's complications to this. The modem needs to be set in "bridge" mode. Essentially, this modem is just a router with only one ethernet port and no wireless. Bridge Mode, makes it JUST a modem, thus letting the router do the PPPoE. This setup, if done right, with the correct packet headers, etc, is the optimal connection, but if done wrong, it causes serious connection problems down the line.
The Versalink modem is nice because it is a modem and router all in one. AKA, none of the above garbage I talked about. Only problem with it, is that it's still the same situation: PPPoE, only this ALL-IN-ONE device is doing the PPPoE.
The software CD that Verizon gives you is nothing more than something that logs onto Verizon's website, let's you create an account. It sets up your mail program (Not sure which ones, probably Mail) and it sets up your device (meaning Versalink or 2200) for PPPoE.
When I got Verizon, I did this all myself. I didn't want Verizon's "spy" software running in the background on my PC. Yes, this was when my main computer was a PC (for good reasons). There's all kinds of "checking" apps, etc. I don't want or need that crap.
So, I called Verizon, had them MAKE me the account, accessed 192.168.1.1, and put in admin/admin (or was it admin/password...one of those) and did the setup on there. Most of the complicated options should be left alone, just the username/password should be entered.
Then, once you get that username, your e-mail address is simply
thatusername@verizon.net <--watch that get spammed

.
If you want additional e-mail addresses, there's a place on dslstart.verizon.com to log in and create other ones. Let me warn you though, their site is extremely buggy and likes to randomly DELETE your additional e-mail addresses, webspace (yes, that whole generous 5MB!), and basically screw with your mind.
Right now, I'll say it. If there's ANY other broadband (preferrably cable) provider near you, I would advise you to look at your other options now. Verizon has pretty bad tech support and will actually REFUSE to send someone to your location to diagnose the problem. They make you do everything on the phone with non-English-native speakers (no offense). It's just not a good experience.
I spent most of my time when I had Verizon DSL messing with it, as it was constantly slowing down, disconnecting etc. I still, spend many days helping other people with the same problems I have had.
Anything else, just ask.

I know my Verizon DSL.
