TCPSER turns a PC serial port into an emulated Hayes compatible modem
that uses TCP/IP for incoming and outgoing connections. It can be
used to allow older applications and systems designed for modem use
to operate on the Internet. TCPSER supports all standard Hayes
commands, and understands extended and vendor proprietary commands
(though it does not implement many of them).
TCPSER can be used for both inbound and outbound connections.

The original source code can be found here:
http://www.jbrain.com/pub/linux/serial/
This forks changes are based upon the rc12 archive dated 11Mar09.
The author also fixed the bug with being unable to connect to real
telnet servers.