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. --vadim
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.
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.
Tell you what -- go run the numbers for any reasonable-sized IP provider, and tell me whether or not they are better off on "metered" service of this type, or with full-time dedicated circuits. Metered service will *always* be more expensive at reasonable to high loads, because the metering and billing costs money to do! -- -- Karl Denninger (karl@MCS.Net)| MCSNet - The Finest Internet Connectivity Modem: [+1 312 248-0900] | (shell, PPP, SLIP, leased) in Chicagoland Voice: [+1 312 248-8649] | 6 POPs throughout the area, all 28.8 equipped Fax: [+1 312 248-9865] | Email to "info@mcs.net" for more information ISDN: Surf at Smokin' Speed | WWW: http://www.mcs.net, gopher: gopher.mcs.net
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
participants (4)
-
Jon 'Iain' Boone -
karl＠mcs.com -
Pushpendra Mohta -
Vadim Antonov