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Re: Re[2]: IRC Server
On Wed, 5 Jul 1995, Evgeny Stambulchik wrote:
[...]
> Thus, maximum RAW i/o you can get with 2400 baud is 2400*16=38,400 bps - not
> much better that mentioned 32,000.
>
[...]
>
> Could you please explain, how with 3.6kHz bandwith lines folks get something
> better than 3600 bps (probably, times some factor near 1, depending on bandwith
> definition)?!
Sure. The physical copper wires that are the telephone line can carry
much more bandwidth that 3.6kHz -- for example, 10BaseT uses wire which
isn't so different from regular phone wire (except it's twisted) and
carries 10Mbps. I bet that at least a few hundred kbps are possible with
regular phone wire (exact numbers, someone?).
The point of the 3.6 Kbps is that this bandwidth was decided upon by the
people who made up the telephone standards -- for VOICE communication, as
this is about the bandwidth needed for voice. They choose the least
possible bandwidth so that it would be possible to multiplex lots of
phone calls over a single line (like T1/E1).
All this means that modem speed is limited not by the wires, but by
hard-coded limits in the exchanges. With local phone calls (i.e. not thru
an exchange), much higher speeds are _physically_ possible.
Gavrie.