Black Box 32144, Manual

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CHAPTER 3: Options: Customizing the Modem Setup
NOTE
If a connection cannot be
established using the
selected protocol LAPM/MNP,
LAPM ONLY or MNP ONLY),
the action the modem will
take depends on the V.42
mode setting. See V.42
MODE.
V.42 bis Operation
Hayes, V.25 bis, Dumb, Leased line
modes (except V.33)
V.42 bis operation provides error
correction with data compression.
Like V.42 error correction, V.42 bis
uses the link access protocol for
modems (LAPM). V.42 bis
operation may be enabled or
disabled.
Break Handling
Hayes, V.25 bis (Async only),
Dumb, Leased line modes (except
V.33)
When error correction is active,
a break signal is relayed with an
“attention” packet. The break
handling option determines how
the attention packet is sent.
NONE. No attention packet
is sent.
DESTRUCTIVE/EXPEDITED
(DESTR/EXP). All data in the
buffer is deleted; the attention
packet is then passed through the
channel.
NON-DESTRUCTIVE/
EXPEDITED (NDT/EXP). The
attention packet is passed through
immediately, but data in the buffer
is not deleted.
NON-DESTRUCTIVE/NON-
EXPEDITED (NDT/NEXP). The
attention packet is passed through
the channel in sequence, and any
data is buffered; this preserves the
sequence of data and breaks
received.
Buffer Mode/Speed Conversion
Hayes, V.25 bis, Dumb, Leased line
modes (except V.33)
This option enables or disables
speed conversion (for
asynchronous operation only)
between the DTE and modem
when error correction is not used.
ENABLE. When error correction
is not active, the V.42 circuit will
function as a buffer between the
DTE and the modem and will
provide transmission-speed
conversion.
DISABLE. Speed conversion is
not allowed.
DTE Speed
Hayes, V.25 bis, Dumb, Leased-line
modes (except V.33)