*BSD News Article 21556


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Newsgroups: comp.os.386bsd.misc
Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!spool.mu.edu!sol.ctr.columbia.edu!usenet.ucs.indiana.edu!bigbang.astro.indiana.edu!pitts
From: pitts@bigbang.astro.indiana.edu (Jim Pitts)
Subject: Re: SLIP problems with NetBSD 0.9
Message-ID: <CE15Ax.8G6@usenet.ucs.indiana.edu>
Sender: news@usenet.ucs.indiana.edu (USENET News System)
Nntp-Posting-Host: bigbang.astro.indiana.edu
Organization: Indiana University Astrophysics, Bloomington, IN
References: <bryan.749160542@fegmania.wustl.edu>
Date: Mon, 27 Sep 1993 20:37:36 GMT
Lines: 49

In article <bryan.749160542@fegmania.wustl.edu> bryan@fegmania.wustl.edu writes:
>Hi!
>
>I'm running NetBSD 0.9 on my 486/33 at home.  I've started playing
>with SLIP and connecting to a machine at work.
>
>I connect fine and the ping times seem pretty reasonable (~250ms).
>If I try to send large amounts of data over the line (like a ftp
>session, etc.) the connection hangs.  If I run another slattach
>the connection will free up... and then eventually freeze again.
>
>What can I do to fix this?  I've heard that the FreeBSD serial
>drivers are more robust... but I would really like to avoid switching
>operating systems again.
>

Nothing that I could find.  The serial drivers for NetBSD and BSD386 blow
chunks (so to speak).  Actually what happens is that they start to lose
bytes of data as their silos overflow.  This happens when the ISA starts
to take clock cycles away from the serial port and it is not smart
enough to compensate.

What you need to do is port the sio device drivers of FreeBSD to whatever
you are running.  This should solve your problems.

The reasons slip (and ppp will do this as well) is dying is because with
the IO driver loses bytes it gets garbled packets.  Slip does not seem to
deal well with these and croaks.  I find this amazing (that it can't
deal with packets like this) because it is an application that is supposed
to run over serial lines (like a phone line) that will trash packets on
a routine basis.

Over a non-slip connection with a modem you will notice zmodem spills its
internals as well.  This is for the same reason.  Zmodem can't survive this
sort of abuse.

I was never able to get NetBSD 0.9 to work with slip/ppp using the serial
driver at 14.4K.  At lower speeds this should work better (but it -is- a
lower speed).  My solution was to use FreeBSD.  It fixed my problem totally.

Not ppp and slip run like a champ.  Zmodem also works great.  The other day
I moved some 10's of MB's of data over the modem with transfer rates
around 1.8 K/s ... not bad!  I also play netrek and serve X over the phone
with no problems.

Good luck.  With NetBSD 0.9 you'll need it.

					Jim