[ih] bang paths, was Domain Names

[John Levine]

In article <69946A38-7AE0-418B-9F1B-696B750A1CF1 at google.com> you write:
>yes the bang-path was parallel.
>
>eventually they met when gateways linked hosts in the two systems.

Bang paths were used for uucp, a dialup network that transferred
mostly mail and usenet messages, although the underlying transport
could move arbitrary files.  It ran for quite a while primarily by
burying its phone costs in corporate overhead budgets.  Its normal
addressing was site!user, but due to something between a bug and a
feature, addresses like sitea!siteb!sitec!user worked to route mail
from site to site.

It even had its own dynamic routing, sort of like the Arpanet but
several orders of magnitude slower.  Uucp sites would publish lists of
who they talked to in a usenet group which was propagated (mostly by
uucp) all over.  At many sites a program called pathalias would crunch
the lists once or twice a day to figure out the shortest bang path for
each site, although at the many stub nodes they just used a default
route to a better connected site.  There were, as Vint noted, gateways
to the Arpanet and other networks, which were handled by mixed
addressing.  For several years my address relative to the Arpanet was
ima!johnl at CCA-UNIX.

Pathalias eventually went away due to the combination of people realizing
that mail worked better if the route wasn't embedded in the address, and
the Internet and DNS becoming widely enough available that everyone could
use MX records for routing.  Uucp is still a pretty good protocol for
transferring mail by phone call, and I still know a site or two that
uses it to transfer mail with RFC822 addresses.

R's,
John