> More expensive boxes are called scanners and cost thousands - they can do > things like testing all OSI layers (ie speak a full smtp session with a > remote host) as well as testing actual voltages, cable lengths, noise > factors, etc.
There's a Dynatel subscriber loop analyser in my work van that can, among other things, test longitudinal balance, insulation resistance, cable length. If everything is within spec then you'll know the cable's OK. I guess you might want to test SNR at frequencies used by 100baseT and 1000baseT, but I don't think the Dynatel does that (not the model I have). Yuri
