pppd command line arguments:

#/usr/bin/pppgo

	#!/bin/sh
	#if [ "$1" = "" ] ;then
	#   echo "Usage: pppon username"
	#   exit 1
	#fi
	#/usr/sbin/pppd /dev/ttyS1 57600 user $1 connect "/usr/sbin/chat -f $HOME/chatscript"

	if [ -f /var/lock/LCK.ttyS1 ]; then
		rm /var/lock/LCK.ttyS1 > /dev/null
	fi
	setserial /dev/ttyS1 autoconfig auto_irq
	# /usr/sbin/pppd /dev/ttyS1 57600 debug defaultroute connect "/usr/sbin/chat -v '' ATD2501956 CONNECT '' ogin: username assword: password"
	# /usr/sbin/pppd /dev/ttyS1 57600 defaultroute connect "/usr/sbin/chat '' ATD2501956 CONNECT '' ogin: username assword: password"
	#(/usr/sbin/pppd 10.0.0.1:10.0.0.2 call isp connect "/usr/sbin/chat -v -r /etc/ppp/report-chat -f /etc/ppp/ppp.chatscript") || exit 1
	while [ "x" ]; do
		/usr/sbin/pppd /dev/ttyS1 115200 modem crtscts lock -detach defaultroute \
			connect "/usr/sbin/chat -f /etc/ppp/chatscript"
		sleep 60
	done
	} & >/dev/null 2>&1
	exit 0

#/usr/bin/pppstop
	#!/bin/sh
	killall -qw pppd > /dev/null
	rm -f /var/lock/LCK..* /var/run/ppp*.pid
	rm -f /etc/ppp/report-chat
	exit 0

Modify the scripts properties.
	% chmod 666 /usr/bin/pppgo	# make executable by all users
	% chmod 666 /usr/bin/pppstop	# make executable by all users