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high speed

High speed in terms of internet connectivity over long distances could be considered as anything better than ISDN. Speed is measured by bits per second, and when the numbers get big, using K or M to bring them down to size. Common speed inter-company data pipelines are T1, or T3 or faster, and these labels are also used as speed measures. A good 56k modem on a clean line will manage at most 48k bits per second. This is roughly 1/30th the speed of a T1. A smallish ISP may share a T1 amongst hundreds of simultaneous dialup sessions. An large office may share a T1 for internet and email traffic amongst 500 employees or more. On the other hand, DSL speeds are commercially available that range from 1/12th of a T1 to 5x a T1. This is truly high speed. Related topics to consider along with pure theoretical speed are also ping time/latency of the connection, sustainable transfer rates versus burst rates, as well as monthly traffic limits, and packet drops. In addition, for windows machines, registry settings can have a big effect on throughput.
Comparing DSL to 56k modems, it is obvious the jump in performance is huge.



Comparing DSL to 56k modems

The famous CNN online home page, without any graphics or adverts loaded, is currently 69k (69 x 1024 characters) big. To transfer this on my 56k modem takes about 13 seconds, and then add more time for my fetch request to reach CNN, their servers to respond, and the time to come back, and then even more time to request, start, and complete loading all the images. No wonder www is thought to stand for World Wide Wait!
In comparison, on a 416k SDSL link, www.cnn.com can load in about 2-4 seconds, and that includes all the images. On a 7.4mbs ADSL link it is even faster, although the limiting factor then becomes speed of the browser and computer, so the perceptual difference between 416k and 7.4mbs is slight. These numbers give you some feel for data rates.
The other thing to consider is latency. A modem adds a latency (ping time) of between 50ms and 250ms depending on how big the data packet is. A DSL modem is more in the order of 7ms, and the rest is up to the quality of the internet. With a latency of 7ms, and 40-70ms for packets of real data, internet resources feel almost as quick as if they were on your local machine, and high speed interactive internet games are free from juddering, freezes, hops, and the infamous quake POD (ping of death).


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