at Tuesday, December 17, 2002 5:33 AM, the following Choatisms were
heard:
> Nobody (but perhaps you by inference) is claiming it is identical,
> however, it -is- a broadcast (just consider how a packet gets routed,
> consider the TTL for example or how a ping works).
ping packets aren't routed any differently from non-ping packets - they
bounce up though your ISPs idea of best route to the recipient's ISP,
who then use their idea of best route to the target (leaving aside the
via IP flag). The reply bounces up their ISP's idea of best route to
your ISP, and down though your ISP's best route to you. There isn't a
sudden wave of "ping packet" travelling out across the internet like a
radar pulse, and reflecting back to you - it is a directed transfer of a
single discrete packet.
The best analogy (made by someone else here earlier) is a telephone
call; each call follows a routing path defined by the phone company's
best idea of pushing comms one step closer to the destination at that
time; it may be that a longer route (bouncing via a third country to get
to a second, rather than using the direct line) has a lower "cost" due
to the usage at that time, so that route is used.
