[1685] in linux-net channel archive
Re: PPP connection busy ...
daemon@ATHENA.MIT.EDU (Al Longyear)
Thu Jan 25 07:11:32 1996
To: jvichere@undergrad.math.uwaterloo.ca (Jan Vicherek)
Date: Tue, 23 Jan 1996 15:19:51 -0800 (PST)
From: "Al Longyear" <longyear@sii.com>
Cc: linux-newbie@vger.rutgers.edu, linux-net@vger.rutgers.edu
In-Reply-To: <Pine.SUN.3.91.960119140722.6903B-100000@legendre.uwaterloo.ca> from "Jan Vicherek" at Jan 19, 96 02:14:53 pm
Jan Vicherek wrote:
> Every several hours I come to my computer and see the RX led on my modem
> going crazy, SD is not so crazy, but blinks on the 14.4 connectin about
> every second or so, and the connection is unusable -- it takes ages for
> me to log in somewhere via the connection. I get login:, and before I
> manage to type is my userID, I get login timeout ...
Are you sure that the modem is not retraining? You may wish to look in your
modem manual for the conditions for the retrain display. My ZyXEL modem
has a "SQ" indicator for this purpose. I have seen it blink-blink-blink
on several occasions.
A 14.4KBPS modem will retrain in the downward direction should the line
condition degenerate. The V.34 modems will go in both directions.
> So I kill pppd and restart pppd. Once new pppd is up, the activity
> doesn't re-appear until several hours later ...
Again, killing pppd is really resetting the modem. It may be co-incidental
that the condition improves because you have stopped pppd. Having stopped
pppd you disconnected the modems and then replaced the call.
> netstat doesn't show any active connections that could cause it.
> (what utility would show me the type and source of the incoming packets ?)
Again, this is leading to a modem<->modem communications rather than
computer<->computer over the modem link.
> What could it be ? And what can I do about it ?
Get a better telephone line?
As an experement, you may wish to turn off the modem's retraining
flag. Each modem has a different command to do this so you will have
to look it up.
The 'down' side of this is that if the modems must retrain because of
a bad line and you have disabled one from participating in the retrain
process then the only option that the modems have is to disconnect.
However, you will have a different symptom. Your connection will break.
If you used a package such as diald and applied the tty patches to the
kernel then diald should automatically bring the link back up.
> How can I find out (== diagnose) what's going on ? And then what do I do ?
There is analog equipmenet for measuring the line quality of your telephone.
I do not know if this will help because the only solution to a bad telephone
line is to pay for more line conditioning. (That does not mean that the
telephone people will come out. It will usually only show up on your
telephone bill. However, you will get a guarantee from the BOC that the
line is of a certain quality and when it falls below that then they will
fix it.)
--
Al Longyear longyear@netcom.com longyear@sii.com
Finger longyear@netcom.com for PGP public key.
