Subject: Re: 486 with 56K modem?
To: Aidan Cully <aidan@kublai.com>
From: Stefan Grefen <grefen@hprc.tandem.com>
List: port-i386
Date: 11/13/1998 10:03:48
In message <19981113021219.A3455@xanadu.kublai.com>  Aidan Cully wrote:
> On Thu, Nov 12, 1998 at 09:55:30PM -0600, Tom T. Thai wrote:
> > I don't think it's the 486 talking to the modem.  Most likely it's your
> > modem talking to the upstream ISP.  It's trying to negotiate but can't for
> > what ever the reason may be, username/password or maybe even 56K
> > compatibility.
> 
> I really doubt that's it, since a) it works fine from Linux, whenever
> it gets carrier, and b) sometimes we do start to negotiate, but it's
> universally unreliable, and I don't think we've yet completely
> negotiated IPCP (though we have started to).  A look at the modem
> lights seems to indicate that we do get data back at the same time as
> we send it, but the pppd logs don't corroborate that.

>From the first mail you send  I giuess that Linux as a 512 MTU and
NetBSD a 1500 Byt MTU. On a slow machine this makes a difference.
Try to set the MTU on NetBSD to a lower value.

Stefan

> 
> ...a bit later...
> 
> Enabling crtscts seemed to let us connect, but here's some netstat
> output from the PPP interface while trying to look at some web pages to
> which we've gotten good throughput through the linux box:
>    input    (ppp0)    output            input   (Total)    output
>  packets  errs  packets  errs colls  packets  errs  packets  errs colls 
>       57    62      314     0     0      4366    62     1832     0     1
>        0     7        9     0     0        20     7       20     0     0
>        1     3        4     0     0        11     3       11     0     0
>        0     3        1     0     0         4     3        3     0     0
> and then the NetBSD box froze up, and it stopped responding to pings or
> keyboard input, and I had to hard-reboot it.  No messages in /var/log to
> clue me in or anything.
> 
> I expect I'll have to do a fair bit more digging..
> --aidan

--
Stefan Grefen                                Tandem Computers Europe Inc.
grefen@hprc.tandem.com                       High Performance Research Center
 --- Hacking's just another word for nothing left to kludge. ---