A Physical Layer Switch (PLS) is a hardware devicethat performs like an electronic patch panel. Userscan send a command to a PLS to change connectionswithout moving cables. The PLS handles data atthe physical (PHY) or first layer of the OSI model ofnetwork architecture. Also known as a Layer 1 Switch, a PLS acts like a wire or cable on the hardware level, and therefore is not aware of and has no influence onthe actual protocol or routing information containedwithin the data stream.