bmanning@ISI.EDU writes:

If the PSTN is the only game in town

The PSTN is dead; the only thing is that the body is still giving off lots of heat so fibre owners haven't begun giving up on it yet. Some of them even appear to be betting that in three days it'll get up and start walking around again. Real money is in computer mediated and computer-to- computer communications, and it's that money which is sustaining the last vestiges of metabolism in the PSTN.

then its ATM or nothing.. and ATM won't cut it at those rates.

Well it's not surprising that telcos still hope to save the PSTN by selling only ATM like in silly cases where a clear-channel colocation-facility-to-colocation-facility SONET run is ignored as a sales option while an ATM PVC of the same general bandwidth takes a thousand-mile detour to and from the nearest ATM switch... Moreover, I'm told that currently on offer from one telco is a OC3 SONET pipe for only ten times the price of a DS3. However, if you want a PVC following the exact same path, the circuit is only a little more than double DS3. (Ironically you can currently do 4:3 SONET/SDH inverse muxing giving you an OC3/STM-1 from 4xDS3 (plan your DS3s along divers paths, kids!). Of course, you can just use various router vendors' strategies for load-balancing among DS3s and use all 4 DS3s as they are, for that matter...) Finally, to tie in a reply to your reply to my previous message, finding ways to light up fibre is not so difficult; at worst it all comes down to massive amounts of MUXing. While I happen to prefer the approach of a combined SONET MUX/IP router to stick at each end of a pair of soliton-containing fibre strands, Vadim Antonov's approach is also tractable and attractive, and has some interesting benefits that could be seen as side effects wbut which he has turned into a real additional-value feature within his proposed product. In any event, let me just say that I disagree with you that "stringing is easy" -- replacing all the crap in the ground in the U.S. now with fibre that has decent chromatic dispersion properties and as little dependence on electro-optical conversion as possible is going to be a long, expensive and labour-intensive process. Hence the window of opportunity for Hans Werner von Braun and his amazing rocketships of death, and similar techologies I'd rather not have to depend on. :-) Sean.