The Routing Over Large Clouds Mailing List Archive by date

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

> > But, as ATM large clouds do not and, in short-term, will not, exist,
> > NHRP is not a short- or long- term answer.
> 
> I don't believe this is true for all values of 'large' and 'short-term'. 
> In Scotland we have 4 Academic MANs based on ATM or mixed ATM/FDDI
> technology.

If your network is really a large cloud, that is, not necessarily
geographically large, but contains a large number of non-IP switches,
then, that is a bad news. It will be an administrative nightmare.

> NHRP MAY help us to avoid either the
> obvious router bottlenecks

"obvious router bottlenecks"? What are they?

Isn't it obvious that cell-switching IP routers, whose cell switching
fabrics are setup by RSVP to have VCs for each flow, are just as fast
as legacy ATM switches?

> or the administrative complexity of
> overlaying a mesh of IP connections over a simple ATM star topology. 

If the mesh of IP connections are necessary only within a subnet,
a small cloud between the cell-switching IP routers, it's administration
is only as complex as the current configuration.

And, are you aware that if you have a large cloud with N nodes and
a mesh of IP connections over a simple ATM star topology, most
links will have O(N^2) VCs? That is, if you use CBR, each VC can't
have high bandwidth.

> Cell switching routers clearly aren't that
> in the short term,

What is clear?

You can order Ipsilon swiches today. You can make a more general
CSR from legacy PVC/SVC ATM switches controlled by a usual UNIX WS
through RS 232c.

It is true that RSVP spec may not fix in the short term, in which
case, we can use ST2 or draft RSVP, can't we?

> and aren't currently the IETF consensus about the way
> to go.

What consensus, do you think, we need?

To let CSR work, we need no new protocol.

When we discussed on the issue of WG creation, Joel Halpern, the
IESG routing Area Director, stated that we can't create a WG only
to develop a router that needs no protocol.

So, the IETF consensus is, seemingly, that to go for CSRs
we need no further IETF consensus.

Anyway, to abandon NHRP, we only need a consensus that it is
proven to not to work.

						Masataka Ohta