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.

  stringing it is easy...
  the where to do it part is harder...
  the hard part is the clever ways to light it...

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.