The Routing Over Large Clouds Mailing List Archive by date

[Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>]

> >In WAN environment on Earth with N nodes and geographical size
> >L, such topology costs O(L*N) for wiring, while mesh like one
> >costs only O(L*sqrt(N)).
> >
> >That is, the architecture is impractical in large cloud WAN,
> >where N is, by definition, large.
> >
> >Note that, in Sam's case, N is not so large.

> Seems that we have another case of talking past each other.  I was talking
> about a LOGICAL star, where the VCs converge on a central point; that says
> nothing about the PHYSICAL network, i.e. how the wires run.

Star topology do says physical wiring cost of O(L*N).

Note that you can't relocate physical location of sites.

> There is no need whatsoever for excess length of the physical circuits.
> The carrier shares the wires among multiple customers, and designs the
> physical topology accordingly.

As you know, a customer with foolish topology must pay a lot to
the carrier.

							Masataka Ohta