i-modul Modem 336 LL
Functions
6.4
Data Compression
The i-modul Modem 336 LL 3.0 supports various data compression types. During the
connection setup, it will automatically detect the type of data compression used by the
remote terminal, or it is set to a certain type of 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 at least recognize and support the same data
compression mode.
The default setting is the automatic selection of MNP-5 and V.42.bis and V.44 data com-
pression (
AT%C3
).
Configuration with AT commands
To select the compression type, use:
AT%C<n>
To completely switch off the compression, use
the following commands:
AT%C0
AT+DS44=0
To select the MNP-4 compression:
AT%C1
To select the V.42 bis and V.44 data compres-
sion if they are switched on (see below):
AT%C2
To select the V.42 bis and MNP-5 data com-
pression if V.42.bis compression is switched on
(see below):
AT%C3
To switch on V.42 bis compression:
AT%C2
To switch on V.44 compression:
AT+DS44=3
To switch off V.42 bis compression:
AT%C0
To switch off V.44 compression:
AT+DS44=0
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