[no subject]

Yes, in the Internet we can technically have multiple address spaces --
that is, multiple roots -- because we have cleanly divided routing (IP
addresses) from addressing (DNS name); and we can't technically have
multiple address spaces in the PSTN, because routing and addressing are
not cleanly divided.  But make no mistake about it: the fact that you
*can* partition the addressing layer without partitioning the routing
layer doesn't make it a good thing, and it doesn't make it any less
problamatic for users.

     -- Brett