Poor John called me, very apologetic, and noted that Speakeasy will be giving me two months of the DSL for free, for the inconvenience of the downtime. He's pretty cross at the Qwest folks, and we're still wondering what's happened to my line -- it seems like every piece of equipment between me and the actual link to Speakeasy has gone down.
To bobson and others who have asked why Covad and Qwest are both involved... how DSL works is something like this. You have the actual phone line itself, which runs to the house; you need a specific quality of line service in order for the DSL to work properly, because it's a digital signal mixed with the normal audio. When the phone line reaches the Central Office, then it's fed through something called a Splitter Card, which takes the voice and data blocks and splits them apart. The data portion is fed through some stuff to decode it, and then sent to a local point-of-presence. At the point-of-presence, the signal is turned into normal TCP packets and sent over a link to the appropriate ISP.
Qwest has a monopoly in Seattle on phoneline installation, pretty much. But Qwest only offers DSL service for Qwest.net customers. Therefore, you need a secondary provider -- such as Covad. The signal comes in over Qwest, and then goes through a sort of tangled area where some stuff happens on Qwest's side and is handed over to Covad, and some stuff happens on Covad's side before being carried to the local point-of-presence for transmission to the ISP.
In my case, the signal goes out over my (Qwest-provided) normal phone line, to the (Covad-managed) set of equipment which carries it to the regional point-of-presence for Speakeasy. You can introduce another layer of complexity when you realize that the line from the point-of-presence to other places is often managed by a different backbone provider (in my case, MCI Worldcom). In this particular case, the problems seem to all be in the area where Qwest and Covad mix together, which led to the two of them blaming each other, Covad finally doing some work, and then discovering there was still more work which needed to be done on Qwest's side.
This is an overly simplified explanation, but hopefully it explains a little of the reasoning behind all of this.