... physical addressing, flow control, and encapsulation. 19WAN Physical Layer ConceptsChapter 1: Introduction to WANsCCNA Exploration 4.020WAN Physical Layer Concepts21WAN Physical Layer Concepts22WAN ... were developed afterwards are based on it. 26WAN Frame Encapsulation Formats•Flag: 8-bit: 011 11110, starts and ends the frame•Address: 1 or 2 bytes, is usually broadcast on a p2p link•Control:...