bmanning@ISI.EDU writes:

And its not clear there is enough capacity in the PSTN to carry all the bits about.

The hard part is stringing fibre around, followed by figuring out clever ways of lighting it up. North America is Geographically Challenged in that respect compared to the greater number of shorter rights-of-way among large customer bases in other parts of the world. For now there is some coasting going on in the U.S. and Canada particular since the traffic crunch is mostly north-to-south. However ultimately trunking east-to-west will fill and that is a much harder bottleneck to widen, and provides interesting opportunties to people deploying things other than fibre in the U.S. Of course, such deployments strike me as unstable economically principally for scaling and failure-avoidance-and-recovery reaosns compared to modern fibre technology. Of NANOG relevance, there are ample war stories of weather-sunspot-and-bat-releated outages on high-bandwidth alternatives to terrestrial paths. *I* wouldn't use a non-fibre (and ideally non-SONET) path where one were avialable if losing connectivity (or alot of capacity) when it stops working were an issue. Sean.