Lecture 3: Local Area Networks

When computers are connected to a physical medium, there must be a way they can grab the attention of other computers to broadcast the message, "Here comes a frame!"
Various technologies have different ways of doing this process, but all frames, regardless of technology, have a beginning signaling sequence of bytes. 10101010…….10101010
Depending up frame format: Preamble = 7 bytes, Start or Start of Frame Delimiter (SFD) = 1 byte 10101011.