cisco

interface
 ip unnumbered Loopback0
 encapsulation ppp
 keepalive 10
 async mode dedicated
 no peer default ip address
line
 modem InOut
 transport input all
 stopbits 1
 rxspeed 115200
 txspeed 115200
 flowcontrol none

freebsd

cat >> /etc/ppp/name
nodetach
/dev/cuaa0
115200
noipdefault
nocrtscts
local
debug
defaultroute
passive
lock

cat >> /usr/local/bin/ppp.loop 
#!/bin/sh
while sleep 3
do
echo "Start ppp" >> /var/log/pppd.log
/usr/sbin/pppd file /etc/ppp/bow
echo "Crash ppp" >> /var/log/pppd.log
done

cat >> /etc/syslog.conf
!pppd
*.*    /var/log/pppd.log