Chat Script Examples

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This section contains chat scripts that you can use as a reference for creating your own chat scripts. The modem manufacturer's guide and information from your ISP and other target hosts contain chat requirements for the modem and your target peers. In addition, numerous PPP web sites have sample chat scripts.

Basic Modem Chat Script

The following is a basic chat script that you can use as a template for creating your own chat scripts.

ABORT   BUSY
ABORT   'NO CARRIER'
REPORT  CONNECT
TIMEOUT 10
"" AT&F1M0&M5S2=255
SAY     "Calling myserver\n"
TIMEOUT 60
OK      "ATDT1-123-555-1212"
ogin: pppuser
ssword: \q\U
% pppd

The next table describes the contents of the chat script.

Script Contents	Explanation
`ABORT BUSY`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT 'NO CARRIER'`	Abort transmission if the modem reports `ABORT 'NO CARRIER'` when dialing. The cause for this message is usually a dialing or modem negotiation failure.
`REPORT CONNECT`	Gather the `CONNECT` string from the modem. Print the string.
`TIMEOUT 10`	Set initial timeout to 10 seconds. The modem's response should be immediate.
`"" AT&F1M0&M5S2=255`	`M0` – Turn off the speaker during connect. `&M5` – Make the modem require error control. `S2=255` – Disable the TIES “+++” break sequence.
`SAY "Calling myserver\n"`	Display the message `Calling myserver` on the local machine.
`TIMEOUT 60`	Reset the timeout to 60 seconds to allow more time for link negotiation.
`OK "ATDT1-123-555-1212"`	Call the remote peer by using the phone number 123-555-1212.
`ogin: pppuser`	Log in to the peer by using UNIX-style login. Supply the user name `pppuser`.
`ssword: \q\U`	`\q` – Do not log if debugging with the `–v` option. `\U` – Insert in this location the contents of the string that follows `–U`, which is specified on the command line. Usually, the string contains the password.
`% pppd`	Wait for the % shell prompt, and run the `pppd` command.

`/etc/ppp/myisp-chat.tmpl` Chat Script Template

This release includes the /etc/ppp/myisp-chat.tmpl, which you can modify for use at your site. /etc/ppp/myisp-chat.tmpl is similar to the basic modem chat script except that the template does not include a login sequence.

ABORT   BUSY
ABORT   'NO CARRIER'
REPORT  CONNECT
TIMEOUT 10
""      "AT&F1"
OK      "AT&C1&D2"
SAY     "Calling myisp\n"
TIMEOUT 60
OK      "ATDT1-123-555-1212"
CONNECT \c

Script Contents	Explanation
`ABORT BUSY`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT 'NO CARRIER`	Abort transmission if the modem reports `ABORT 'NO CARRIER'` when dialing. The cause for this message is usually a dialing or modem negotiation failure.
`REPORT CONNECT`	Gather the `CONNECT` string from the modem. Print the string.
`TIMEOUT 10`	Set initial timeout to 10 seconds. The modem's response should be immediate.
`"" "AT&F1"`	Reset the modem to factory defaults.
`OK "AT&C1&D2"`	Reset the modem so that, for &C1, DCD from the modem follows carrier. If the remote side hangs up the phone for some reason, then the DCD drops. For &D2, DTR high-to-low transition causes the modem to go “on-hook” or hang up.
`SAY "Calling myisp\n"`	Display the message “Calling myisp” on the local machine.
`TIMEOUT 60`	Reset the timeout to 60 seconds to allow more time for link negotiation.
`OK "ATDT1-123-555-1212"`	Call the remote peer by using the phone number 123-555-1212.
`CONNECT \c`	Wait for the `CONNECT` message from the opposite peer's modem.

Modem Chat Script for Calling an ISP

Use the next chat script as a template for calling an ISP from a dial-out machine with a U.S. Robotics Courier modem.

ABORT   BUSY
ABORT   'NO CARRIER'
REPORT  CONNECT
TIMEOUT 10
"" AT&F1M0&M5S2=255
SAY     "Calling myisp\n"
TIMEOUT 60
OK      "ATDT1-123-555-1212"
CONNECT \c
\r \d\c
SAY "Connected; running PPP\n"

The following table describes the contents of the chat script.

Script Contents	Explanation
`ABORT BUSY`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT 'NO CARRIER'`	Abort transmission if the modem receives this message from the opposite peer.
`REPORT CONNECT`	Gather the `CONNECT` string from the modem. Print the string.
`TIMEOUT 10`	Set initial timeout to 10 seconds. The modem's response should be immediate.
`"" AT&F1M0M0M0M0&M5S2=255`	`M0` – Turn off the speaker during connect. `&M5` – Make the modem require error control. `S2=255` – Disable the TIES “+++” break sequence.
`SAY "Calling myisp\n"`	Display the message `Calling myisp` on the local machine.
`TIMEOUT 60`	Reset the timeout to 60 seconds to allow more time for link negotiation.
`OK "ATDT1-123-555-1212"`	Call the remote peer by using the phone number 123-555-1212.
`CONNECT \c`	Wait for the `CONNECT` message from the opposite peer's modem.
`\r \d\c`	Wait until the end of the `CONNECT` message.
SAY “Connected; running PPP\n”	Display the informative message `Connected; running PPP` on the local machine.

Basic Chat Script Enhanced for a UNIX-Style Login

The next chat script is a basic script that is enhanced for calling a remote Oracle Solaris peer or other UNIX-type peer. This chat script is used in How to Create the Instructions for Calling a Peer.

        SAY "Calling the peer\n"
        TIMEOUT 10
        ABORT BUSY
        ABORT 'NO CARRIER'
        ABORT ERROR
        REPORT CONNECT
        "" AT&F1&M5S2=255
        TIMEOUT 60
        OK ATDT1-123-555-1234
        CONNECT \c
        SAY "Connected; logging in.\n"
        TIMEOUT 5
        ogin:--ogin: pppuser
        TIMEOUT 20
        ABORT 'ogin incorrect'
        ssword: \qmypassword
        "% " \c
        SAY "Logged in.  Starting PPP on peer system.\n" 
        ABORT 'not found'
        "" "exec pppd"
        ~ \c

The following table explains the parameters of the chat script.

Script Contents	Explanation
`TIMEOUT 10`	Set initial timeout to 10 seconds. The modem's response should be immediate.
`ABORT BUSY`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT 'NO CARRIER'`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT ERROR`	Abort transmission if the modem receives this message from the opposite peer.
`REPORT CONNECT`	Gather the `CONNECT` string from the modem. Print the string.
`"" AT&F1&M5S2=255`	`&M5` – Make the modem require error control. `S2=255` – Disable the TIES “+++” break sequence.
`TIMEOUT 60`	Reset the timeout to 60 seconds to allow more time for link negotiation.
`OK ATDT1-123-555-1234`	Call the remote peer by using the phone number 123-555-1212.
`CONNECT \c`	Wait for the `CONNECT` message from the opposite peer's modem.
`SAY "Connected; logging in.\n"`	Display the informative message `Connected; logging in` to give the user status.
`TIMEOUT 5`	Change the timeout to enable quick display of the login prompt.
`ogin:--ogin: pppuser`	Wait for the login prompt. If the prompt is not received, send a RETURN and wait. Then, send the user name `pppuser` to the peer. The sequence that follows is referred to by most ISPs as the PAP login. However, the PAP login is not related in any way to PAP authentication.
`TIMEOUT 20`	Change the timeout to 20 seconds to allow for slow password verification.
`ssword: \qmysecrethere`	Wait for the password prompt from the peer. When the prompt is received, send the password `\qmysecrethere`. The `\q` prevents the password from being written to the system log files.
`"% " \c`	Wait for a shell prompt from the peer. The chat script uses the C shell. Change this value if the user prefers to log in with a different shell.
`SAY "Logged in. Starting PPP on peer system.\n"`	Display the informative message `Logged in. Starting PPP on peer system` to give the user status.
`ABORT 'not found'`	Abort the transmission if the shell encounters errors.
`"" "exec pppd"`	Start `pppd` on the peer.
`~ \c`	Wait for PPP to start on the peer.

Starting PPP right after the CONNECT \c is often called a PAP login by ISPs, though the PAP login is actually not part of PAP authentication.

The phrase ogin:--ogin: pppuser instructs the modem to send the user name pppuser in response to the login prompt from the dial-in server. pppuser is a special PPP user account name that was created for remote user1 on the dial-in server. For instructions about creating PPP user accounts on a dial-in server, refer to How to Configure Users of the Dial-in Server.

Chat Script for External ISDN TA

The following chat script is for calling from a dial-out machine with a ZyXEL omni.net. ISDN TA.

        SAY "Calling the peer\n"
        TIMEOUT 10
        ABORT BUSY
        ABORT 'NO CARRIER'
        ABORT ERROR
        REPORT CONNECT
        "" AT&FB40S83.7=1&K44&J3X7S61.3=1S0=0S2=255
        OK ATDI18882638234
        CONNECT \c
        \r \d\c
        SAY "Connected; running PPP\n"

The following table explains the parameters of the chat script.

Script Contents	Explanation
`SAY "Calling the peer"`	Display this message on the screen of the dial-out machine.
`TIMEOUT 10`	Set the initial timeout to 10 seconds.
`ABORT BUSY`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT 'NO CARRIER'`	Abort transmission if the modem receives this message from the opposite peer.
`ABORT ERROR`	Abort transmission if the modem receives this message from the opposite peer.
`REPORT CONNECT`	Gather the `CONNECT` string from the modem. Print the string.
`"" AT&FB40S83.7=1&K44&J3X7S61.3=1S0=0S2=255`	The letters in this line have the following meaning: `&F` – Use factory default `B40` – Do asynchronous PPP conversion `S83.7=1` – Use data over speech bearer `&K44` – Enable CCP compression `&J3` – Enable MP `X7` – Report DCE side rates `S61.3=1` – Use packet fragmentation `S0=0` – No auto answer `S2=255` – Disable TIES escape
`OK ATDI18882638234`	Make an ISDN call. For multilink, the second call is placed to the same telephone number, which is normally what is required by most ISPs. If the remote peer requires a different second phone number, append “+`nnnn`.”. `nnnn` represents the second phone number.
`CONNECT \c`	Wait for the `CONNECT` message from the opposite peer's modem.
`\r \d\c`	Wait until the end of the `CONNECT` message.
`SAY "Connected; running PPP\n"`	Display this message on the screen of the dial-out machine.

Refer to the chat(1M) man page for descriptions of options and other detailed information about the chat script. For an explanation of expect-send strings, refer to Chat-Script Field in /etc/uucp/Systems File.

For More Chat Script Examples

A number of web sites offer sample chat scripts and assistance in creating the chat scripts. For example, see http://ppp.samba.org/ppp/index.html.