> I'm familiar with the old-style IDs such as "914-1" for White Plains
>> etc., but I've never been able to figure out how the current system
>> is supposed to work.
> It doesn't work, really, and is actually becoming less and less
> relevant as the network topology flattens. The New Orleans 4ESS is
> probably among the last of its breed, and I remember hearing that AT&T
> removed a lot fo them from service long ago as they shifted towards a
> decentralized network.
Many thanks for the explanations. As you might have guessed, I'm still not fully conversant with the way the North American network was structured even before the modern era, but I'm gradually piecing the story together from various sources.
-Paul