Technical information

Telnet Client Operation
2-94 AT+i Commands Reference Manual May 31, 2008
Telnet Client Operation
There are four operation modes for most Telnet applications, namely, half-duplex, character at a
time, line at a time, and line mode.
W24 incorporates two methods to send data to the remote Telnet server: One line at a time,
namely, an AT+i command (+iTSND) is used to send a single (CR/LF terminated line to the
Telnet server); and Binary Transmission, where an AT+i command (+iTBSN) is used to send an
arbitrary amount of binary data.
Data is retrieved from the remote Telnet server as it is made available. Embedded Telnet options
in the server's response stream are stripped by W24 before being turned over to the host.
Telnet specifies many operational options. W24 restricts its operation mode to the minimum
implementation to assure best intersystem compatibility.
Following are the Telnet options negotiated by W24:
Any other options negotiated by the Telnet server are rejected by W24.
Option ID Name Value RFC
1 echo OFF 857
3 suppress go ahead suppress 858
24 terminal type VT100 1091
31 window size whatever 1073