3Com 10014299 manual Restore the ex-factory modem settings, AT&b1&c1&d2&s0=0

Modem Configuration Examples 755

Restore the ex-factory modem settings

To restore the ex-factory modem settings, use the “AT&F” command.

[Router]script-string factory "" AT OK AT&F OK

[Router]interface serial 0

[Router-Serial0]start-chat factory

Configure the modem initialization parameters

Correctly initializing the modem configuration is an important step for the correct connection with the modem. The following contents briefly introduce the conventional AT initialization commands and the works for initialization.

■When the negotiation is being carried out between modems, the modem speed must not be changed. Otherwise, the user should send an AT command to the remote modem so that the modem can be set to the new speed.

■The port speed must not change when a session is negotiated with a remote modem. If the speed of the port on the access server is changed, you must establish a direct Telnet session to the modem and send an AT command so that the modem can be set to the new speed.

■Modems differ in the method they use to lock the EIA/TIA-232 serial interface speed. Refer to the modem documentation to learn how the modem locks the modem speed (check the settings &b, \j, &q, \n, or s-register settings).

■The modem must use the data carrier detect (DCD) to indicate when a connection is established with a remote end. Most modems use the &c1 command to implement the configuration. Refer to the modem documentation for details.

■The modem must disconnect the modem active connections via the data terminal ready (DTR) signals. Most modems use &d2 or &d3 to implement the setting. Refer to the modem documentation for details.

■If the modem is required to access incoming calls, it must be configured with the number of off-hook ringing for incoming calls. The user should not to adopt the ringing auto-answer mode. S0=0 is adopted to make the configuration for most of the modems. For details, please refer to the modem operation manuals provided by the related manufacturers.

Considering the previously listed situations, the following initialization string is designed for typical applications:

AT&b1&c1&d2&s0=0

The initialization string enables the following functions:

■Locks the speed of the modem to the serial interface speed

■Enables DCD

■Enables disconnection of DTR

■Configures the non-auto answer

[Router]script-string init "" AT&b1&c1&d2&s0=0 OK

[Router]interface serial 0

[Router-Serial0]start-chat init