ATM Utility

Jon 'Iain' Boone boone at
Tue Nov 1 20:53:24 UTC 1994

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.

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