What Is a Model?Why Use a Model?OSI ModelOSI—Beyond the LayersOSI/ITU-T ProtocolsIntroducing TCP/IPTCP/IP and the RFCsThe Practical Side of TCP/IPEncapsulationAddressingEquipmentReadingSummaryReview QuestionsReview AnswersLab ExercisesActivity 1—Examining EncapsulationActivity 2—Protocol DistributionActivity 3—Developing a Protocol/Architecture