2.2
SNM15
Functional Features
Digicom SpA
Error correction and data compression
Transmission optimizing techniques have been introduced to
ensure faultless data transmission.
These techniques are made up of a line protocol acting as a logical
means of transport with functions of supervising the transmitting
device and optimizing the data transmission speed.
SNM15 implements 2 error correction tecniques: MNP4 and
CCITT V.42.
When using the error check it is indispensable to use the flow
control (see command &U); in fact, if the features of the line when
being connected become worse, the modem will be forced to
retransmit many blocks several times.
This might lead to the saturation of modem buffer (especially if
there is continuous traffic coming from the DTE) and without
appropriately handling the flow control (CTS or XON and
XOFF) many of the data being transmitted that are parked in the
DCE, would be overwritten by data continuously emitted by the
associated DTE.
In the DIGICOM SNM 15 modem V.42/V.42bis and MNP
functions are available in both the AT and the V.25bis
(asynchronous) environments; the configuration and enabling/
disabling stages can be controlled in the AT mode.
