Moxa V2401-LX [46/108] Ppp point to point protocol

V2401/2402 Series Linux User’s Manual Managing Communications

3-19

PPP (Point to Point Protocol)

PPP (Point to Point Protocol) is used to run IP (Internet Protocol) and other network protocols over

a serial link. PPP can be used for direct serial connections (using a null-modem cable) over a

Telnet link, and links established using a modem over a telephone line.

Modem/PPP access is almost identical to connecting directly to a network through the

V2401/2402-LX’s Ethernet port. Since PPP is a peer-to-peer system, the V2401/2402-LX can also

use PPP to link two networks (or a local network to the Internet) to create a Wide Area Network

(WAN).

ATTENTION

Click on the following links for more information about PPP.

http://tldp.org/HOWTO/PPP-HOWTO/index.html

http://axion.physics.ubc.ca/ppp-linux.html

Connecting to a PPP Server over a Simple Dial-up Connection

The following command is used to connect to a PPP server by modem. Use this command for old

ppp servers that prompt for a login name (replace “username” with the correct name) and

password (replace “password” with the correct password). Note that “debug crtscts” and

“defaultroute 192.1.1.17” are optional.

#pppd connect ‘chat -v ““ ATDT5551212 CONNECT ““’ ogin: username word: password’

/dev/ttyS0 115200 debug crtscts modem defaultroute 192.1.1.17

If the PPP server does not prompt for the username and password, the command should be entered

as follows. Replace “username” with the correct username and replace “password” with the correct

password.

#pppd connect ‘chat -v ““ ATDT5551212 CONNECT ““’ user username password password

/dev/ttyS0 115200 crtscts modem

The pppd options are described below:

connect ‘chat etc...’ This option gives the command to contact the PPP server. The chat

program is used to dial a remote computer. The entire command is

enclosed in single quotes because pppd expects a one-word argument

for the connect option. The options for chat are given below:

-v verbose mode; log what we do to syslog

“ “ Double quotes—don’t wait for a prompt, but instead do ... (Note that you

must include a space after the second quotation mark)

ATDT5551212 Dial the modem, and then ...

CONNECT Wait for an answer.

“ “ Send a return (null text followed by the usual return)

ogin: username word: password

Refer to the chat man page, chat.8, for more information about the chat utility.

/dev/ Specify the callout serial port.