Intro to Computer Networks: Lecture 1 - Network Models, Transmission Tech, and Layered Des, Study notes of Computer Systems Networking and Telecommunications

Download Intro to Computer Networks: Lecture 1 - Network Models, Transmission Tech, and Layered Des and more Study notes Computer Systems Networking and Telecommunications in PDF only on Docsity! 1 1 ECE453 - Introduction to Computer Networks Lecture 1: Introduction 2 Computer Networks - Definition A collection of autonomous but interconnected computers 3 Hardware Component local ISP company network regional ISP router workstation server mobile Network edge vs. Network core 2 4 Network Edge end systems (hosts) Client Server client/server model peer-peer model 5 Two Types of Communication Models – Client-Server Model 6 Two Types of Communication Models – Peer-to-Peer Model 5 13 The Layered Design of Computer Network 14 Why Layered? (An Example) ticket (purchase) baggage (check) gates (load) runway takeoff airplane routing ticket (complain) baggage (claim) gates (unload) runway landing airplane routing airplane routing D ep ar ti ng a ir po rt ar ri vi ng a ir po rt intermediate air traffic sites airplane routing airplane routing 15 Why Layered Architecture? explicit structure allows identification, relationship of complex system’s pieces modularization eases maintenance, updating of system change of implementation of layer’s service transparent to rest of system e.g., change in gate procedure doesn’t affect rest of system To conquer complexity 6 16 OSI vs. TCP/IP application presentation session transport network link physical application transport network link physical 17 Layering: Logical Communication application transport network link physical application transport network link physical application transport network link physical application transport network link physical network link physical data data data ap l i n appli i ack E.g.: application Open a brower Type in web address (send in a request) wait for peer to ack receipt and return result 18 Layering: Physical Communication application transport network link physical application transport network link physical application transport network link physical application transport network link physical network link physical data data 7 19 Three Concepts Services Interfaces Protocols 20 Primary Services Provided in Each Layer Application (end system) Client/server paradigm Application layer protocol design Transport layer (end system) Reliable data transfer service Congestion control Multiplexing/demultiplexing service Network layer Routing addressing Link layer Error correction addressing Flow control Physical layer