Subject: Re: ppp compression...
To: None <>
From: John Maier <>
List: netbsd-users
Date: 06/09/2001 09:58:42
> Nope. The ISP doesn't have compression at all. They bought their newer
> portmasters without the stac compression cards.
> Bummer that.

I run an ISP and I have Bay RAC 8000's and 5399's all over the place.  When
I took over, I noticed that Stac and BSD compressions were turned off.  I
thought this strange and turned it all back on.

I started seeing strange occurrences on connections.  Windows 98 machines
would successfully negotiate the Stac compression and go along ok for a few
moments and then link would seem to freeze, couldn't ping, then it would
come back after 30 sec give or take a little.  I turn off stac compression
and the problem went away.

A friend, who defected to Linux, was dialing into me and the pppd messages
in syslog were very interesting.  It seemed that the BSD compression
supported was rather old (on the Bay) and pppd spend several LCP passes
renegotiation for a BSD compression version that the Bay and pppd could
agree upon.  After it got a BSD compression version it liked it went on.
Things were okay for him between 12 and 48hr but the BSD compression would
just break down and finally the only thing to do was to disconnect and
reconnect.  NetBSD tended to work better but there was an occasional problem
that NetBSD at least seemed to be able to recover from.  I finally just
turned off the BSD compression on the Bay.

I personally like the Bays (better than the Cisco) but the compression
technology leaves a lot to be desired.  However, I found that the gains from
compression were very marginal (but measurable) and the trade off for slim
increased performance were not worth reliability.