Mnp 2/3/4 Error Correction; Data Compression; V.42Bis Data Compression - Siemens Insys 56k Operating Manual

Pocket Modem 56k
5.3.2

MNP 2/3/4 Error Correction

The MNP error correction can be operated either in block or in
stream mode. The maximum block size can be set to either
64 byte
128 byte
192 byte
and 256 byte.
The MNP error correction can either be set automatically or
activated via AT commands.
5.4

Data Compression

The modem will identify the type of data compression used by
the other modem, or it is fixed on a certain type or no data
compression.
Data compression is only available for error corrected
connections.
To be able to use data compression, both sides (sender and
recipient) must be able to recognize the same data compression
mode.
5.4.1

V.42bis Data Compression

Switch on V.42bis data compression
Switch off V.42bis data compression
V.42bis data compression may only be performed for a V.42
connection (LAP-M or MNP 4). First of all, V.42bis generates a so-
called dictionary for the data compression, which contains
frequently used character sequences. After that, only short
references to these character sequences and not the complete
character sequences are transmitted to the other modem.
V.42bis cannot re-pack packed data.
Dezember 05
Function
AT\A0
AT\A1
AT\A2
AT\A3
AT\Nn
AT%Cn
AT%C3
AT%C0
AT%C2
AT%C3
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