Noel;
> > From: Caitlin Bestler <[EMAIL PROTECTED]>
>
> > Given the source interface, the *meaning* of an IP header is not
> > supposed to be dependent on the routing tables. ..
> > By contrast, the meaning of an ATM circuit is dependent on the context
> > in which it was established. There is no expectation that there is any
> > meaning to this circuit identifier beyond those imparted when the
> > circuit was created.
>
> Yes, but that's just a minor engineering decisions, i.e. the use of a
That's the essential requirement for networks capable of best effort
service to let all the packets have globally routable addresses.
> non-global namespace for circuit ID's. It's easy to imagine an ATM-like system
> in which circuit ID's are global in scope.
RSVP is a case.
> The real crucial *architectural* difference is in the fact that there is
> per-flow state, along with the need to set up state before the packets can
> flow.
RSVP establishes the per-flow state before the packets can flow.
It is just a minor engineering decision to allow optional circuit
switched service over a best-effort-capable network.
Masataka Ohta
