Specifying ALTERNATE SPEED

Specifying ALTERNATE SPEED

Description

The ALTERNATE SPEED characteristic is only used with full MODEM CONTROL access servers.

Two speeds for a modem port can be defined in the access server database: primary and alternate (or fallback). The primary speed is defined with the speed characteristic; the ALTERNATE SPEED is defined with the ALTERNATE SPEED characteristic. You normally set up the primary speed as the high speed and the ALTERNATE SPEED as the low speed. For ALTERNATE SPEED to work, you must specify a single input/output speed for the speed characteristic.

If an ALTERNATE SPEED is specified, the access server asserts the DSRS signal along with DTR and RTS when receiving a connection. DSRS indicates that the higher primary speed should be used.

The access server monitors the SMI signal to determine whether to use the higher or lower speed. When SMI is asserted, the access server selects the higher speed; when SMI is deasserted, the communications selects the lower speed. The modem connected to the access server must support the SMI signal in order for ALTERNATE SPEED to work; otherwise, erroneous data transmission can occur. To determine whether the modem supports the SMI signal, refer to your modem’s documentation.

The ALTERNATE SPEED feature can be used with dial-out (sends calls) modems. For dial-in (receives calls) modems, you should enable autobaud and disable ALTERNATE SPEED. This allows you to configure the dial-in modem to any speed supported by both the modem and the access server.

Configuring Modem Signals 10-13

Page 185
Image 185
HP NetRider manual Specifying Alternate Speed