6. PPP Configuration

Make an easy link to your modem device:

ln -s /dev/ttyS1 /dev/modem

Now change to the /usr/sbin directory and look for ppp files. Look for either a pppsetup or a pppconfig script. You may directly start this script to set up PPP on your system. On my Slackware system I typed pppsetup and started the script. This script asks for various parameters for connecting via the ISP.

• It first asks for the phone number to dial -- enter "atdt#777", where 777 is replaced by the number that you need to dial.

• It then asks for the modem -- select /dev/ttyS1

• Baud Rate -- select "115200"

• Callback -- Answer "NO"

• Modem INIT String -- "ATZ OK "at+crm=1" OK"

• ISP Domain Name -- Leave blank

• DNS Server Address -- Enter a valid DNS Server IP, for instance "202.41.97.3" or "202.41.97.132", or leave blank

• Authentication -- "PAP"

• Username

• Password

Refer to Section 3 for Username and Password.

Finally it shows you your configuration.

Some more work needs to be done. We need to edit the options file present in the /etc/ppp folder. We need to check if the following entries are present in the file:

lock
defaultroute
noipdefault
modem
/dev/ttyS1
115200
crtscts
noauth
passive
asyncmap 0

	The noauth option
	Remember that noauth is by default commented; you need to uncomment it.

You can use egrep -v '#|^ *$' /etc/ppp/options to list only the options present in this file so as to quickly judge which ones are missing or incorrect.