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Re: 28800 modems?



fixed

At 11:01 PM 4/22/97 -0400, Don wrote:
>
>Dumb question, doesn't telco basically have a effective datarate on
>switched analog lines of about 37kb???  


33.6, if the modem ads are any indication.    (:

>From what I've read, this is the max (after you add in v.32bis v.42bis etc
etc) that you can cram thru an analog phone line.

Except if you use the x2 technology, which (as I understand it) 'cheats,'
and takes advantage of the way the phone system works.

The phone company hates the newer modems, with the data compression and
error correction.  They built the long distance lines with the expectation
of voice connections... and there's a lot of 'quiet' on a voice call.  They
planned on using the silence with their multiplexers so they could get more
calls in a single channel.  Modems, on the other hand, effectively cram data
across the entire voice bandwidth all the time; there is no 'quiet' time, so
a modem call can't be multiplexed.


--Paul E Musselman
PaulMmn@ix.netcom.com

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