Specifications
Chapter 9 – Data Commands
Multi-Tech Systems, Inc. CDMA AT Commands Reference Guide (PN S000294K) 57
V.42 bis Data Compression +DS
Description: This command enables or disables V.42bis data compression if this feature is provided on the PSTN in the
IWF.
Values: Four numeric sub-parameters are accepted:
<dir> specifies the desired direction(s) of operation of the data compression function; from the DTE point
of view. Default is 3.
0 Negotiated … no compression
1 Transmit only
2 Receive only
3 Both directions, accept any direction
<neg> specifies whether or not the DCE should continue to operate if the desired result is not obtained.
Default is 0
0 Do not disconnect if V.42 bis is not negotiated by the remote DCE as specified in <dir>
1 Disconnect if V.42 bis is not negotiated by the remote DCE as specified in <dir>
<P1>
512-4096 Specifies the maximum number of dictionary entries that should be negotiated.
Default is 4096.
<P2>
6-250 Specifies the maximum string length to be negotiated. Default is 250.
Syntax: Command syntax: AT+DS=<dir>,<neg>,<P1>,<P2>
Command Possible Responses
AT+DS=3,0,4096,250
Note: Set new parameters
OK
Note: Command valid
AT+DS?
Note: Current values
+DS: 3,0,4096,250
OK
Note: Command valid
V.42 bis Data Compression Report +DR
Description: This command returns the results of data compression capability. If data reporting is enabled, this command
returns the data compression type of an incoming or outgoing data call. Otherwise, the command returns
NONE.
The intermediate result code represents current DCE-DCE data compression type. The syntax for +DR
reporting is: +DR<result>, and the result code is defined as follows:
+DR: NONE Data compression is not in use
+DR: V42B Rec. V.42 bis is in use in both directions
+DR: V42B RD Rec. V.42 bis is in use in receive direction only
+DR: V42B TD Rec. V.42 bis is in use in transmit direction only
The +DR intermediate result code, if enabled, is issued before the final result code, before the +ILRR
intermediate report and after the service report control +CR.
Values: This syntax is for setting the +DR reporting method.
<val>
0 Disable reporting
1 Enable reporting
Syntax: Command syntax: AT+DR=<val>
Command Possible Responses
AT+DR=1
Note: Reporting enabled
OK
Note: Command valid
AT+DR?
Note: Display the current value
+DR: 1
OK
Note: Command valid
AT+DR=?
Note: Display the supported values
+DR: (0,1)
OK
Note: Command valid