ATM Utility

Vadim Antonov avg at
Mon Oct 31 18:06:44 UTC 1994

>I believe that ATM, even in its perhaps immature state, is useful and
>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.


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