On the command line, or on the [File] New connection dialog box, you can specify the TCP port number (<TCP port#>) and telnet flag (<telnet flag>) for a TCP/IP connection. If these parameters are omitted in the command line, the default values are taken from the Tera Term setup file.
Only if <telnet flag> is 1 (on) and <TCP port#> is 23, Tera Term starts spontaneously sending telnet commands to the host for the option negotiation when the TCP/IP connection is established.
This particular port number for telnet, 23, can be changed by editing the TelPort line in the [Tera Term] section of setup file like the following:
TelPort=<telnet port#> Default: TelPort=23
Whatever <TCP port#> is and whatever <telnet flag> is, Tera Term can respond to telnet commands sent by the host.
For a non-telnet TCP/IP connection (usually with a port other than 23), you may need to set the "local echo" option on, and the "new-line (transmit)" option to CR+LF. If you edit the TCPLocalEcho and TCPCRSend lines in the [Tera Term] section of the setup file like the following:
TCPLocalEcho=on TCPCRSend=CRLF (CR is also acceptable)
the "local echo" option is turned on and the "new-line (transmit)" option is set to CRLF automatically when the connection is established on condition that <telnet flag> is 0 (off), or <TCP port#> is not equal to <telnet port#>. Otherwise, setup values specified by [Setup] Terminal are used. By using these options, one setup file can support both the telnet connection and non-telnet connection.
Default: TCPLocalEcho=off (This option is disabled and the "local echo" option in the [Setup] Terminal dialog box is always used.) TCPCRSend= (This option is disabled and the "new-line (transmit)" option in the [Setup] Terminal dialog box is always used.)