User's Manual

Modem 34336

The available error correction options are listed below:

• V.42 Mode • DTE Speed

• MNP Class (class limit) • DTE-DCE and DCE-DTE Flow

• Break Handling

Control options

• V.42 Selection • Flyback Buffer

• Buffer Mode/Speed Conversion • Pass-Through Flow Control

All of the above options affect the type of error correction selected via the

V42 SELECTION screen (discussed below), except that the MNP Class and

Flyback Buffer options are applicable only to MNP operation.

The error-correction options can be selected in any order, but the following

sequence is suggested:

1. Select the type of error correction desired from the V42 SELECTION screen.

2. Make a selection from the V.42 Mode screen.

3. Select other error-correction options as appropriate for your application.

The V.42 Mode is available for Hayes, V.25 bis, Dumb, and Leased-Line

modes (except V.33).

The V.42 Mode settings described below apply to the type of error correction

selected with the V42 Selection screen. For example, if LAPM ONLY is

selected as the error correction protocol, and MANDATORY is selected

from the V42 Mode screen, V.42 or V.42 bis error correction is activated.

If the error correction cannot be activated, the Modem will hang up.

• OFF — Error correction will be disabled.

• MANDATORY — Error correction will be activated. If the modem cannot

establish a connection using the type of error correction selected via the

V.42 Selection option, it will hang up.

• AUTO — The Modem will fall back to buffer or non-buffer mode if

conditions do not allow it to establish a connection using the type

of error correction selected via the V42 SELECTION screen.

The MNP Class (Limit) is available for Hayes, V.25 bis, Dumb, Leased Line

modes (except V.33). This option is effective only when MNP error correction

is active. It limits MNP operation to the selected MNP class or lower (MNP

classes 1-5 are available). In general, the higher MNP classes provide the most

throughput efficiency. Class 5, the default, can provide as much as 2-to-1 data

compression over the transmission link.