OK, all... here's the lowdown on your questions - from the 'horse's mouth'. I work for SBC, in the DSL sales office for SWBT area. YMMV for PacBell, Ameritech, or SNET areas.
1) If you've already got SBC DSL service, even if you're under a current contract or paying more, you CAN rerate to $29.95/mo for another year. Call 1 877-722-3755, options 3, then 1. The voice option says this is "to cancel your service" but it sends you straight to our retentions group, who can place the change order right then and there. We're open from 8:00 am - 7:00 pm central Mon-Fri and 8:00 am - 5:00 pm Sat. If you have existing SBC DSL service, the new term will start the day you order. The lower rate may take 1 - 2 billing cycles to show the new rate, but will continue for 12 months. This is due to the nature of the billing beast and the FCC requiring SBC to separate the ordering office (SWBT) from the ISP (SBC Internet Services). You are, at that point, liable for early term fees of $200 if you disconnect the DSL service before the 12 month term is up without good cause...(please don't flame me on that part...). If you rerate, your current service shouldn't be affected at all (i.e. speeds, etc.)
2) There is no 30 day grace period. If you're getting new service, it starts billing on your due date - If you order by calling 1 877-372-3755 options 3 then 2, we can nearly always get 1 week due dates.
2a) To get DSL to your address, the central phone serving office has to be equipped with DSL equipment which has to be provisioned and connected to your phone line. In some cases, better service is available to you if a remote terminal (RT) has been built in your neighborhood. By the way, this same equipment has to be shared with any other ISP who wants to provide DSL to their customers. And, because we have to share, we also have to give them priority, which is partly why we have to take a week to set it all up.
3) The only software that needs installed is a version of PPPoE, either the Enternet 300 on the install CD, the built-in PPPoE in Windows XP, or what may be in your router.
4) If you're using a router, we don't care how many PC's/Mac's are accessing the service at one time. Nothing against the Linux/Unix user's out there, but our lovely tech support group is not trained, nor does SBC Internet support, any OS besides Windows 98 - XP, and Mac 8.6 - 10.1 excluding 10.0 - 10.04. Existing users still get support for Windows 95.
4a) TommyBoy8 is right - 2 modems won't work. They'd be fighting each other for the same signal.
5) We don't cap the amount of data you upload or download. Your upload speeds will be capped at a steady 128 kbps, unless you opt for a faster package (costs more, though). Download speeds will also be steady, but will vary depending on your distance from the central office (C/O). Again, depending on the package, we do have minimum download speeds. Please realize that these speeds are just from you to the local C/O.
6) Changing your speeds won't result in any downtime, unless doing so would require switching your DSL service from C/O based to RT based.
Hope this helps...
TextRT:light: