Digicom 3911, 3910 operation manual 42/MNP/Buffer

COMSPHERE 3900 Series Modems

Table 5-5

(6 of 6)

Leased Line Configuration Options

Lease_Lookback: Disable

Nxt Disable Enable

Lease Lookback. While operating on backup lines, this configuration option allows the modem to test the primary 4-wire leased lines for connectivity by detecting line energy across the normal line bandwidth. This test of the primary lines will not interrupt the data flow on the backup lines. The configuration option settings must be the same at both ends.

Dual_Leased_Ln: Disable

Nxt Disable Enable

This configuration option is only available when the Dual Leased Line device option is installed.

Dual Leased Line. Allows the 2-wire backup facility to function as a 2-wire leased-line facility. When this configuration option is disabled, the backup facility is a 2-wire dial line.

NOTE: Plug the leased line into the jack labeled DIAL on the rear panel of the modem. Except for dialing, ring indication, and call progression functions, you control the backup function as if it were a normal dial backup.

NOTE: Once the Dual_Leased_Ln configuration option is enabled, the Bakup_TXClk_Src configuration option can be enabled.

BackupLineCheck: Disable

Nxt Disable Enable

This configuration option is only available when the Dual Leased Line device option is installed.

Backup Line Check. Tests the backup circuit for availability while the modem is operating on the primary leased lines. The test involves detecting line energy across the normal bandwidth. This test of the backup lines will not interrupt the data flow on the primary lines. The configuration option settings must be the same at both ends.

NOTE: In network applications where the modem is in backup mode and is connected to a modem other than the modem connected to the primary leased-line, enabling this configuration option can cause problems.

V.42/MNP/Buffer

V.42/MNP/Buffer configuration options determine the type of error correction and flow control used by the modems and attached DTEs.

Some choices within this group may not appear depending upon how previous configuration options have been selected. If the Async/Sync Mode configuration option is set for synchronous operation (refer to the DTE Interface configuration options group), then the V.42/MNP/Buffer group does not appear on the LCD. Any changes made to configuration options within this group only take effect after a disconnect.

Table 5-6 shows each V.42/MNP/Buffer configuration option as it appears on the LCD, with the Async Dial factory default setting shown following the colon ( : ) on the first line and with all available selections listed on the second line. Following this is a description of the configuration option. Factory default settings are listed in Appendix F.

5-38 September 1998 3910-A2-GN32-40