The configurations of AT+QICFG="tcp/retranscfg",<max_backoffs>,<max_rto> and
AT+QICFG="tcp/keepalive",<keepalive>,<idle_time>,<interval_time>,<probe_cnt> take effect to all
TCP sockets and cannot be saved to NVM.
<transpkt_size> Integer type. Maximum length of the data packet to be sent. Range: 1-1460.
Default value: 1024. Unit: byte.
<transwaittm> Integer type. In transparent access mode, if the length of data received from
the port is less than the value specified by <transpkt_size>, after exceeding
the time specified by <transwaittm>, the data will be sent directly.
Range: 0-20. Default value: 2. Unit: 100 ms.
<send_data_format> Integer type. Format of the data to be sent.
0 Text mode
1 Hex mode
<recv_data_format> Integer type. Format of the data to be received.
0 Text mode
1 Hex mode
<view_mode> Integer type. Output format of received data.
0 Output format: data header\r\ndata.
1 Output format: data header,data.
<recv_ind> Integer type.
0 URC format without data length.
URC format: +QIURC: "recv",<connectID>
1 URC format with data length.
URC format: +QIURC: "recv",<connectID>,<data_len>
<IPv6_prefix> String type. Network-specific prefixes or a well-known prefix.
<prefix_length> Integer type. Prefix length. The values are 32, 40, 48, 56, 64 and 96. Unit: bit.
<max_backoffs> Integer type. Maximum number of TCP retransmission. Range: 3-20. Default
value: 12.
<max_rto> Integer type. Maximum interval of TCP retransmission.
Range: 5-1000. Default value: 600. Unit: 100 ms.
<keepalive> Integer type. Whether to enable TCP keepalive feature. When it is 0,
<idle_time>, <interval_time> and <probe_cnt> should be ignored.
0 Disable TCP keepalive feature
1 Enable TCP keepalive feature
<idle_time> Integer type. Default keepalive time. Range: 1-120. Unit: minute.
<interval_time> Integer type. Time between keepalive probes. Range: 25-100. Unit: second.
<probe_cnt> Integer type. Maximum number of keepalive probes. Range: 3-10.
<IPv6_prior> Integer type.
0 Set IPv4 as the prior PDP type
1 Set IPv6 as the prior PDP type