|
|
The physical layer is the hardware level of the protocol model that is concerned with electronic signals. Physical layer protocols send and receive data in the form of packets.
A packet contains a source address, the transmission itself, and a destination address.
TCP/IP supports a number of different hardware at the physical layer including Ethernet, Token-Ring, and Fiber Distributed Data Interface (FDDI) on local area networks (LANs). It also supports the PPP and SLIP point-to-point protocols used with wide area networks (WANs) established over the public telephone system.