Digicom 3910, 3911 operation manual 42/MNP/Buffer Configuration Options

DCP Configuration

Table 5-6

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V.42/MNP/Buffer Configuration Options

Err Contrl Mode: V42/MNPorBfr

Nxt V42/MNPorBfr V42/MNPorDsc MNP_or_Buffr MNP_or_Disc BufferMode DirectMode

LAPM_or_Disc LAPM_or_Bufr

This configuration option is only available if Async/Sync Mode is configured for Async.

Error Control Mode. Determines the type of error control used by the modem. In most cases, V42/MNPorBfr is the best choice. If V.42bis and MNP are enabled, then the modem uses the following priority for error control negotiation: V.42bis, V.42, MNP 5 and below. Online changes do not take effect until a disconnect occurs.

HV.42/MNP or Buffer

Modem attempts to connect in V.42 Error Control mode using V.42 Link Access Procedure for Modems (LAPM) protocol. If this fails, the modem attempts to connect in MNP mode. If this fails, the modem connects in Buffer mode and continues operation. This is also known as V42/MNP Autoreliable Mode.

HV.42/MNP or Disconnect

Modem attempts to connect in V.42 Error Control mode using V.42 LAPM protocol. If this fails, the modem attempts to connect in MNP mode. If this fails, the modem disconnects. This is also known as Reliable mode.

HMNP or Buffer

Modem attempts to connect in MNP mode. If this fails, the modem connects in Buffer mode. This is also known as MNP Autoreliable Mode.

HMNP or Disconnect

Modem attempts to connect in MNP mode. If this fails, the modem disconnects. This is also known as Reliable mode.

HBuffer Mode

Modem does not use error control and allows the DTE rate to differ from the communications line rate. This mode should only be used if the DTE provides its own error control or if errors in data can be tolerated. This setting is also known as Normal mode and is valid even if the remote modem is set to Direct mode.

HDirect Mode

Modem connects at a data rate equal to or less than the initial DTE interface rate. (The modem never connects at a data rate greater than the initial DTE rate.) If the modem connects at a data rate lower than the DTE rate, the DTE must then adjust its data rate to equal the modem rate.

Ultimately, the modem speed and DTE speed must be the same. Direct mode does not support error control or data buffering.

HLAPM or Disconnect

Modem attempts to connect in LAPM mode. If this fails, the modem disconnects.

HLAPM or Buffer

Modem attempts to connect in LAPM mode. If this fails, the modem connects in Buffer mode.

NOTE: The modem must be reconfigured for Direct mode before changing the leased-line modulation if V.42 error control or Buffer mode are enabled with V.32bis or TMp on leased lines.

3910-A2-GN32-40 September 1998 5-39