[rbridge] MAN scale and future uses of Rbridge

[Peter Ashwood-Smith]

> >   The protocols do not know how they are being applied. They
> > are either
> > mathematically correct or not so I assume you are either 
> talking about
> > scale or migration? 
> 
> About scalability, yes.
> 
> Regards,
> Rute

  In general link state type procotols of which IS-IS and therefore
Rbridge is an example scale better than distance vector style protocols,
of which  STP is a varient. 

  This is one reason for the dominance of OSPF over RIP at L3. 

  Shortest paths are of course of interest in the MAN but other reasons
why Rbridge is attractive in the MAN consist of future uses of its link
state topology. In particular as Alia pointed out, RAPID style rerouting
(loop free alternates) is possible. Also the link state topology is
useful for constraint based routing. So let's not rule out larger scale
in the future, especially since this is where Rbridge will really shine.

  Peter