Ericsson T39 At Command Reference page 193

Test command:
Test command
response:
Parameters:
<iws>:
<mws>:
<t1>:
<N2>:
<ver>:
<T4>:
AT+CRLP=? Shows if the command is supported.
+CRLP: (list of supported <iws>s),(list of supported <mws>s),(list of supported
<t1>s),(list of supported <n2>s)[,<ver1>[,(list of supported <T4>s)]]<CR><LF>
[+CRLP: (list of supported <iws>s),(list of supported <mws>s),(list of supported
<t1>s),(list of supported <n2>s)[,<ver2>[,(list of supported <T4>s)]]<CR><LF>
[...]]
<iws>
0-61
61
<mws>
0-61
61
<t1>
38-100
48
<N2>
0-255
6
<ver>
integer
<T4>
3-100
5
Description
IWF to phone window size
Default setting
Description
Phone to IWF window size
Default setting
Description
Acknowledgement timer T1 setting, in 10 ms steps
T1=480 ms
Default setting
Description
Number of re-transmission attempts, N2
Default setting.
Description
RLP version
When version indication is not present,
<ver>=0 is assumed
Description
Resequencing period T4, in 10ms steps
Default setting
AT Commands Modem Terminated 191