CNIT 240 FINAL EXAM REVIEW ACTUAL 2025/2026 QUESTIONS AND 100% CORRECT ANSWERS

CNIT 240 FINAL EXAM REVIEW ACTUAL 2025/2026 QUESTIONS AND 100% CORRECT ANSWERS What are the components of communications? - Answer -- source - destination - message - transmission medium What is a layered approach to communications? - Answer -- provides a logical breakdown in functions, operations, responsibilities, maintainance, and management of a system - each layer performs a specific set of functions or tasks - layers rely on other layers to perform their specified tasks - use defined interfaces to communicate between layers - provides the opportunity to improve, enhance, replace components of the system without need to replace entire system List some communication reference models - Answer -- Open System Interconnection (OSI) - TCP/IP- Input-Process-Output (IPO) What is the OSI model? - Answer -- defines 7 layers in order to describe end-to-end communications between any two systems - provides open interconnections between layers (ie. can support multivendor environments) What are some of the OSI model's rules for communication? - Answer -- communication between layers is handled in specified (defined) manner - each layer is only able to communicate with its adjacent layers - each layer relies on layers below it to perform their specified function - each layer relies on layers above it to perform their specified function What are the 7 layers of the OSI model? - Answer -"Please do not throw sausage pizza away" (bottom to top) - physical layer - data link layer - network layer - transport layer - session layer - presentation layer - application layerWhat is the physical layer of the OSI model? - Answer -- responsible for transmission and receipt of bit stream to/from nodes - solely concerned with signaling techniques (activating, maintaining, terminating physical circuit) - electrical, mechanical, and functional control of data communications circuits in networks - will pass received information up to layer 2 - does NOT include the physical media!! - passes bit stream to layer 2 for frames/cells construction - provides buffering for frame fragments - performs a simple "error-detection" routine (at signal level) What is the data link layer of the OSI model? - Answer -- responsible for providing POINT-TO-POINT validity of the data (via point-to-point checking/correction; CRC is most common approach) - not all LAN architectures can support reliable delivery (must verify frame integrity; acknowledge that each frame was received intact) - UTILIZES FRAMES! - converts data to frames - independent address architecture from other layers - procedures and protocols for reliably operating communication links What are the data link sub-layers? - Answer -MAC functions - ensures access to shared medium