Having just relocated to Colorado with three of these modems (I accumulated them after years of SBC/AT&T DSL service back in Connecticut), I decided that I might as well try getting one of them to work on my new Qwest circuit before spending money on a Qwest-approved modem.
Since Qwest does not support the SpeedStream 5260, I turned to the Internet to see if anyone else had done anything like this before. What I discovered is that every DSL provider seems to use its own specific VPI/VCI settings, and “ISP approved” modems are usually just pre-configured with the correct settings. For example, the correct VPI/VCI values for AT&T DSL are 0/35, while Qwest uses 0/32. So it seems that all you need to do is find out the correct VPI/VCI values for your ISP and reconfigure your modem to match.
But how do you manage a SpeedStream 5260 when it’s just acting as a bridge? As it turns out, you can always access it via telnet at its default IP address (10.0.0.1). Just give your PC a static IP address (e.g. 10.0.0.2/255.0.0.0) and plug it directly into the modem with a regular straight-through cable. Once at the command prompt, type the following command:
This will list the current VCI/VPI settings on the modem. To change them for Qwest DSL, set the VPI to 0 and the VCI to 32:
set vc 0 32 llc max
These commands appear to take effect immediately (i.e. there doesn’t seem to be a command to save the config).
Update: None of this applies if you happen to be on one of the newer VDSL2 connections. In that case, it looks like you’re stuck with a Qwest-supplied modem for now.