Choked Output Queue with FreeBSD PPP and Demon G5
Andy Long
equipment. I was just wondering if anyone else running a similar config may
have had any such probs.
I run FreeBSD 3.2 (I know I should upgrade but it would be a big job) on
relatively new hardware (16550A uarts) with a Eicon Diva T/A ISDN modem
connected via serial to the machine. I then obviously connect via ISDN to
the G5 isdn number.
After being connected for a relatively long period of time (>1-2 hrs) all
connectivity will cease and my /var/log/ppp.log will simply have
Dec 2 19:08:32 hostname ppp[925]: Phase: Clearing choked
output queue
Dec 2 19:08:33 hostname ppp[925]: Phase: Clearing choked
output queue
repeated several times. I have tried turning on more complete logging but I
don`t have a huge amount of disk space to play with.
I have been running this config for over 12 months, connecting until
recently to BT Internet. I used that service connected for similar periods
of time and transferred similar amount of data and had no such issues. Does
anyone have similar experiences or feel able to shed any light on my
problem.
Many Thanks
Andy Long
Mark Knight
Long <andy...@yahoo.com> writes
>I am having a problem with FreeBSD's user land PPP and maybe Demon's G5
>equipment. I was just wondering if anyone else running a similar config may
>have had any such probs.
>
fyi - Brian Somers (maintainer of user ppp in FreeBSD) wrote:
I've see this before when playing with my Eicon Diva T/A (although I
usually use an ISDN card).
Basically, the problem is that your connection is wedging - it's
either jammed up or you can no longer connect to Demon. ppp has a
default internal packet queue length of 20 - it'll read up to 20
packets from your interface, and will sit on them 'till either they're
sent or the ``choked timer'' happens (and the entire queue is
dumped). The choked timer is reset every time any data is sent and
defaults to a 2 minute timeout.
When the connection wedges, you'll see lots of these messages - until
the connection is active again.
I've seen this on my TA and discovered that the TA itself seemed to be
wedged. Doing a ``show physical'' showed that there was data in the
tty queue (outq) that just didn't want to go anywhere, despite the TA
thinking that everything was fine.
Re-opening the link make everything work again....
For what it's worth, have a look at the ppp man page for ``set
choked'' and ``set ifqueue''. There's not much you can do about this
though....
--
Mark Knight
Tel: +44 (0)7973 410732 http://www.knigma.org/