nanog mailing list archives

Re: ATM Utility


From: Bob Doyle <bdoyle () sprint net>
Date: Wed, 2 Nov 1994 09:41:33 -0500

Also, please also do not confuse Vadim's individual opinion with the opinion 
of Sprint.  Sprint also recognizes the cost-benefits of a fast packet service 
versus point-to-point circuits.  One of the primary reasons we pursued an ATM 
strategy in advance of many others was due to the cost-benefits in our 
backbone...There are a litany of other reasons which I would be happy to 
pontificate...Pushpendra, no criticism intended, but I would probably argue 
that our stockholders do not consider the cost of additional network capacity 
as "funny-money"....

Bob Doyle
Sprint

From: Pushpendra Mohta <pushp () CERF NET> 
Message-Id: <199411020630.WAA05172 () mystic cerf net> 
Subject: Re: ATM Utility 
To: boone () prep net (Jon 'Iain' Boone) 
Date: Tue, 1 Nov 1994 22:30:14 -0800 (PST) 
Cc: avg () sprint net, tjs () msc edu, nanog () merit edu, nap () hq si net 
In-Reply-To: <Pine.ULT.3.91.941101155015.2348E-100000 () nic prep net> 
from "Jon 'Iain' Boone" at Nov 1, 94 03:53:24 pm 
X-Usmail: CERFnet, P.O. BOX 85608, San Diego, CA 92186-9784 
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Jon 'Iain' Boone writes: 

On Mon, 31 Oct 1994, Vadim Antonov wrote: 

cost-effective in a number of applications today.  In particular, 
the cost of wide-area DS-3 ATM services can be very attractive 
when compared to a number of point-to-point DS-3s. 

TAANSTAFL.  You keep forgetting that underneath ATM there are the 
same SONET or clearline DS-3s/OC-3s etc.  So, just by using IP 
routers instead of ATM switches you get 30% more bandwidth for the 
same price. ATM does not appear to make economical sense when 
applied to both data and voice communications.  So, from the point 
of view of a user purchasing something carriers offer ATM may make 
sense (if carrier does not offer native IP) -- but from the point 
of view of a carrier ATM does not look that attractive. 

You still have to run IP over ATM (there's no such thing as native 
ATM applications yet), and the extra level of encapsulation does 
not bring anything worth 30% of bandwidth. 

In terms of real switching capacity (i.e. user data payload) the 
new generation of IP routers is pretty much close to ATM 
switches -- and quite cheaper. 

  But, if you don't need the full 45 Mb/s, you can find a more 
cost-effective solution in the wide-area Fast-packet services.  In 
the case of the MCI Hyperstream offerings, you don't have to pay for 
the full amount of a circuit from point A to point B -- you simply 
pay a monthly subscription fee and then a usage charge per Megabyte 
of data. 

  So, you can build a multi-megabit/s backbone that is (say) 10 Mb/s 
and not end up having to purchase the entirety of the DS3 circuits 
needed to provision it. 


Indeed. 

Vadim works for a phone company, where long haul SONET links are 
funny money. Not like the rest of us :-) 

--pushpendra 

Pushpendra Mohta              pushp () cerf net        +1 619 455 3908 
Director of Engineering                             +1 800 876 2373 
CERFNet 




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