There are only so many providers of VoIP hardware, with branded (and locked) VoIP boxes from companies such as . Engin's latest version is the Engin's Voicebox 3102, which is itself a Linksys SPA3102 Voice Box.
As ATAs (Analog Telephone Adaptors) go, the 3102 is quite unremarkable. It's a small silver box -- good if you don't want lots of "techy" looking stuff cluttering up your phone table -- with phone, line, Ethernet and Internet ports labelled on the back. Engin also supplies a short length of Ethernet and phone line cable in the box, along with the requisite power adaptor. A set-up CD is provided, although this proved problematic for us; it's not Mac OS X compatible, and when trying to run it under Windows Vista, it proclaimed that the set-up routine wouldn't run on Windows 95 or NT machines. Now there's an odd error for you. Thankfully, like most ATAs, it's equipped with an IP-based Web interface -- more on that later.
The 3102's primary function is of course routing voice calls, but it's also equipped with a PSTN pass-through port. What this means is that unlike a straight VoIP ATA, when you plug in your phone and line to the 3102, it's also capable of receiving calls on your regular POTS phone line number. If your VoIP goes down -- either due to an ISP problem, or a problem at Engin's end -- then the 3102 defaults back to the POTS system.