RJ45-sized embedded TCP/IP device

Commander X – LANTRONIX, Inc.

According to their webpage:

Although it is smaller than your thumb, the XPort contains all of the hardware and software required to Web-enable any device, including:

10Base-T/100Base-TX auto-sensing Ethernet connection

Mature, robust operating system

Embedded HTTP-compliant Web server

Programmable e-mail alerts

Extensive networking protocol suite including full TCP/IP stack

128-bit AES Rijndael encryption

Has to be investigated more…