I'm not sure if this is a NetBSD problem, or a 486 problem, or a heavily-
overloaded VLB problem..  I suspect a combination of the last two.  Has
anyone here had any luck getting a 486 to talk to a 56K modem?  I wanted
this old box to take over the routing for our home network, but whenever
I start pppd, it looks like the modem drops characters during LCP
negotiation.  Here's some of the output from ppp.log with debugging
enabled:

Nov  3 09:10:40 albatross pppd[328]: pppd 2.3.5 started by aidan, uid 0
Nov  3 09:11:11 albatross pppd[328]: Serial connection established.
Nov  3 09:11:12 albatross pppd[328]: Using interface ppp0
Nov  3 09:11:12 albatross pppd[328]: Connect: ppp0 <--> /dev/tty00
Nov  3 09:11:12 albatross pppd[328]: sent [LCP ConfReq id=0x1 <magic 0x98bb7fa2> <pcomp> <accomp>]
Nov  3 09:11:12 albatross pppd[328]: rcvd [LCP ConfAck id=0x1 <magic 0x98bb7fa2> <pcomp> <accomp>]
Nov  3 09:11:15 albatross pppd[328]: sent [LCP ConfReq id=0x1 <magic 0x98bb7fa2> <pcomp> <accomp>]
Nov  3 09:11:33 albatross last message repeated 6 times
Nov  3 09:11:33 albatross pppd[328]: rcvd [LCP ConfReq id=0x1 < 00 04 00 00> <mru 1524> <asyncmap 0xa0000> <auth pap> <pcomp> <accomp> < 11 04 05 f4> < 13 09 03 00 c0 7b 72 6e d9>]
Nov  3 09:11:33 albatross pppd[328]: sent [LCP ConfRej id=0x1 < 00 04 00 00> < 11 04 05 f4> < 13 09 03 00 c0 7b 72 6e d9>]
Nov  3 09:11:36 albatross pppd[328]: sent [LCP ConfReq id=0x1 <magic 0x98bb7fa2> <pcomp> <accomp>]
Nov  3 09:11:42 albatross last message repeated 2 times
Nov  3 09:11:45 albatross pppd[328]: LCP: timeout sending Config-Requests
Nov  3 09:11:45 albatross pppd[328]: Connection terminated.
Nov  3 09:11:47 albatross pppd[328]: Exit.

>From my linux box, the same pppd, the same options &c.:

Nov  3 12:22:06 xanadu pppd[2384]: pppd 2.3.5 started by aidan, uid 1001
Nov  3 12:22:38 xanadu pppd[2384]: Serial connection established.
Nov  3 12:22:39 xanadu pppd[2384]: Using interface ppp0
Nov  3 12:22:39 xanadu pppd[2384]: Connect: ppp0 <--> /dev/ttyS0
Nov  3 12:22:39 xanadu pppd[2384]: sent [LCP ConfReq id=0x1 <mru 552> <asyncmap 0x0> <magic 0x35cfd957> <pcomp> <accomp>]
Nov  3 12:22:39 xanadu pppd[2384]: rcvd [LCP ConfReq id=0x1 < 00 04 00 00> <mru 1524> <asyncmap 0xa0000> <auth pap> <pcomp> <accomp> < 11 04 05 f4> < 13 09 03 00 c0 7b 72 6e d9>]
Nov  3 12:22:39 xanadu pppd[2384]: sent [LCP ConfRej id=0x1 < 00 04 00 00> < 11 04 05 f4> < 13 09 03 00 c0 7b 72 6e d9>]
Nov  3 12:22:39 xanadu pppd[2384]: rcvd [LCP ConfAck id=0x1 <mru 552> <asyncmap 0x0> <magic 0x35cfd957> <pcomp> <accomp>]
Nov  3 12:22:39 xanadu pppd[2384]: rcvd [LCP ConfReq id=0x2 <mru 1524> <asyncmap 0xa0000> <auth pap> <pcomp> <accomp>]
Nov  3 12:22:39 xanadu pppd[2384]: sent [LCP ConfAck id=0x2 <mru 1524> <asyncmap 0xa0000> <auth pap> <pcomp> <accomp>]
Nov  3 12:22:39 xanadu pppd[2384]: sent [PAP AuthReq id=0x1 user="private" password="private"]
Nov  3 12:22:39 xanadu pppd[2384]: rcvd [PAP AuthAck id=0x1 ""]

until we eventually get the local/remote IP from the other end.  LCP
authentication works great on the linux box, but not the NetBSD.  It
takes forever to receive a ConfReq from the other end, but we ConfRej
it and never get a subsequent ConfReq (this is not quite universally
the case..  sometimes we do get the ConfReq, and even start PAP
authentication, but not once has it happened as soon in the negotiation
chain as with the Linux box.).  It looks like the NetBSD box is simply
dropping a lot of input from the other end.

Here's the relevant dmesg output:
NetBSD 1.3H (ALBATROSS) #1: Sat Nov  7 14:47:28 PST 1998
    aidan@albatross:/usr/local/sup/src/sys/arch/i386/compile/ALBATROSS
cpu0: family 4 model 3 step 5
cpu0: Intel 486DX2 (486-class)
real mem  = 16384000
avail mem = 13324288
using 225 buffers containing 921600 bytes of memory
...
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
...
com1 at isapnp0 port 0x2f8/8 irq 3: ns16550a, working fifo
...

and my /etc/ppp/stuff
/etc/ppp/options
tty00
115200
debug
modem
defaultroute
mru 552
asyncmap 0
call isp

/etc/ppp/peers/isp
noauth
name private
novj
connect "/usr/sbin/chat -f /etc/ppp/scripts/isp"

which is all the same as on our Linux box, and pppd works fine under
NetBSD with our internal 288 modem.

Thanks for any pointers..
--aidan