The IP over ATM Mailing List Archive by date

[Curtis Villamizar <curtis@ans.net>]

In message <96012912323065@engr05.comsys.rockwell.com>, Albert E. Manfredi writ
es:
> 
> OUTBOUND TRAFFIC
> 
> The ATM network has to provide a DNS and ARP-like service.
> 
> If an ATM host wants to open a session with another ATM host on the same 
> IP flatnet, the DNS will provide the ATM address of that other ATM host.
> The NNI takes care of routing.
> 
> If an ATM host wants to communicate with a legacy IP host, the ATM-DNS
> query results in the ATM address of one (or more, for reliability) router 
> which is, for simplicity, the closest to that DNS server.
> 
> Note that this DNS server can easily provide the minimal ARP function 
> required of it. Edge routers are not expected to change very often, and 
> each server only worries about one or very few edge routers. Also note 
> that I didn't make an unamiguous distinction between DNS server and ARP 
> server.


To summarize your proposal: The ATM flatnet is then using "shortest
path out" routing and essentially using default routing as well.  The
other media is also doing "shortest path out" to the ATM flatnet LIS.
There is no transit of non-ATM across ATM flatnets, but there can be
transit across non-ATM media to reach disjoint ATM flatnets.

If there is significant traffic between the ATM flatnet and the other
media and the traffic is near symetric (approximately equal amount of
traffic in both directions), then there needs to be equal bandwidth
for this on the other media as there is on the ATM media.  There is
also no hope to transit the ATM flatnet.

Now lets look at transition.

This would mean that initially a provider hoping to become a player in
the Internet market in some portion of the world) would have to either
build two infrastructures, one ATM, and one not using ATM, or pay
other providers for transit.

It would seem to me to be much more attractive to the potential user
of ATM in this scenario (trying to make a dent in the global Internet
market) if ATM could be used to transit non-ATM traffic.  This way
such a user of ATM could be selling transit service rather than buying
it.  If another provider also uses ATM, but supports routing, they can
reach all the non-ATM places without paying all the transit fees or
supporting the two infrastructures you have to support.

You may even need more than 90% to make this work.  If you have the
capital to take 90% of the global Internet market overnight, then who
can argue with you.  If not, an ATM flatnet is a very bad choice.

Curtis

ps- Even if you do have the capital, you still haven't addressed the
issue of how the limited VC space problem gets solved for a large ATM
flatnet (which would presumably make host to host connections that get
concentrated into OC12 and OC48 or higher).  You also haven't solved
the problem of connection setup overhead for all these very short
lived host to host connections (DNS packets, short lived WWW flows,
etc).  Carving small VPs either destroys QoS capability or brings back
the inefficiency of TDM by fixing the VP bandwidth allocations and
rate shaping the VPs.