Serial over LAN (SOL) is a mechanism that enables the input and output of the serial port of a managed system to be redirected over IP on a local area network (LAN).
[1] On some managed systems, notably blade server systems, the serial ports on the managed computers are not normally connected to a traditional serial port socket.
For example, a user wishing to access a blade server via the serial port can telnet to a network address and log in.
On the blade server the login will be seen as coming through the serial port.
SOL is implemented as a payload type under the RMCP+ protocol in IPMI.