On Thu, 21 Nov 2002 12:22:27 EST, [email protected] wrote:
>1) The maximum possible modem-to-modem connect speed through the PSTN is V.34 
>33,600 bps.  To get V.90 speeds you must have a V.90 modem connected to a 
>"digital modem" at the central office.  In other words, there is only one 
>analog hop in a V.90 connection.  V.90 works fine for internet access, but 
>V.90 is not possible for two analog modems connected through the PSTN.
>

>3) The maximum 33,600 bps rate for a V.34 modem requires an extremely clean 
>channel.  For example, this rate can only be achieved on about 5% of the 
>connections through the North American PSTN.  On the other hand, a good V.34 
>modem will achieve rates of at least 26 K on over 90% of the connections 
>through the PSTN.

Comment please:

I have two USR 5560 PC Card modems hooked up back to back over a very 
clean circuit (basically just two battery-feed circuits connected by
two 1 uF capacitors).   My terminal program always reports connection
at 31200 V42bis whether I enable or disable compression.  Why might I not 
get 33600?  Could it be something about the modems?

Thanks to all of you who offered comments on this.

Jeffrey Race

Reply via email to