A mechanism is provided for storage enclosures to communicate with one
another using pre-existing cables allowing the user to dynamically attach
different types and speeds of Fiber Channel enclosures together. The
mechanism uses a transmit disable line and receive loss of signal line of
a small form-factor pluggable optical cable to provide a communication
link between enclosures before the Fiber Channel loop is setup and
stable. The mechanism on the transmit side pulses the transmit disable
line to communicate configuration information. The mechanism on the
receive side receives the configuration information on the receive loss
of signal line. The transmit disable line and the receive loss of signal
line operate as a one-wire communication scheme, providing a
communication link to communicate configuration information before the
Fiber Channel loop is established.