PPP and seriel connection

From: Allison J Parent <allisonp_at_world.std.com>
Date: Tue May 12 10:29:16 1998

<Now it is possible that the modems I had available then were different
<from current ones, this was in 1993 and I was working with 1200 or 2400
<baud modems.

No difference. DC on the line was used to sense off hook. It's possible
to ignore the associated line status bit, standard software(dialers,
terminal emulators" would likely look at it and indicate an error. Most
modems use this to indicate a live line and not already in use.

Carrier tone (dial tone) is the next level up to indicating a live line
and dialing is possible.

In any case if these are worked around one modem must be originate and
the other answer so the signal sense is correct.

While it could be handy and made for a real simple two wire interconnect
it's slower than serial direct.

<If you can give me references to documents describing modem and phone lin
<electrical standards I would appreciate it.

Not handy, I'm sure it's on the net.


Allison
Received on Tue May 12 1998 - 10:29:16 BST