The Routing Over Large Clouds Mailing List Archive by date

["Andrew G. Malis" <malis@nexen.com>]

As has been noted on the list, there has been a lot of "interest" (a
polite word for "hype") lately in the industry with regard to cell
switching routers.

However, I (as an equipment purchaser) would think twice before
purchasing any router, cell switching or otherwise, that doesn't meet
at least the most important requirements in RFC 1812 (Requirements for
IP Version 4 Routers).  High on the list is the requirement to
decrement TTL and not forward packets with a TTL of zero.  Ipsilon,
for one, recognized this requirement and found one way to work around
it while switching at the cell layer; I'm sure that there are other
solutions as well.

Given the existence of CSRs, does the need for NHRP go away?  My own
opinion is that the need for NHRP probably goes away when ALL routers
on an NBMA network are integrated into the NBMA-layer switching fabric
(so, for example, every ATM switch is also a router), and router hops
are no more expensive than non-router hops (because there AREN'T any
non-router hops).

However, I also think the reality is that neither non-cell-switching
routers nor non-router ATM switches will be going away for quite some
time, if ever, thus the need for NHRP.

Cheers,
Andy