[net.periph] RV3451PA dialer timeout

henry (10/29/82)

We recently had our dialer in the shop here for a checkout.  We'd had
considerable trouble dialing out with it.  It turns out that a non-trivial
part of the problem was the time delay between the end of dialing and
the recognition of carrier from the other end.  Note that the 3451PA
is a "blind" dialer, which does not recognize things like ringing from
the other end.  This blindness goes deeper than is obvious, though:  it
is not smart enough to listen to the beep and figure out which 1200-baud
protocol the other end wants to use.  It just tries 3400, waits 5 seconds,
and then switches to 212.  I believe it goes back and forth until it
either hits it right or times out.

Now, all this becomes much more serious if you bear in mind that a
long-distance call can take 15 seconds or more to go through, and the
3451PA times out after 25 seconds!  In theory, there may be just enough
time;  in practice, it just doesn't work that way.

The fix?  Easy.  Remember that you put a "k" in the number to give a
5-second pause.  Just slap a couple of those on the *end* of the number
to delay the start of the timeout until the connection is almost ready.
It makes a big difference.

faunt (11/03/82)

Yep, he's right. Works like a champ.  Just add those K's on the end,
and gets right in there.