COE 341 Data Computer Communications T 081 Dr

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COE 341: Data & Computer Communications (T 081) Dr. Marwan Abu-Amara Chapter 1: Data

COE 341: Data & Computer Communications (T 081) Dr. Marwan Abu-Amara Chapter 1: Data Communications & Networking Overview

Acknowledgements Many figures, slides, and course notes were made available by: n Pearson Prentice-Hall

Acknowledgements Many figures, slides, and course notes were made available by: n Pearson Prentice-Hall q n Mc. Graw-Hill q n Data & Computer Communications, W. Stallings Data Communications & Networking, B. Forouzan Previous Course Offerings at KFUPM COE by: q q q Dr. Radwan E. Abdel-Aal Dr. Ashraf Mahmoud Dr. Taha Landolsi COE 341 – Dr. Marwan Abu-Amara 2

Course Outline n n n n Data Communications & Networking Overview (Ch. 1) Protocol

Course Outline n n n n Data Communications & Networking Overview (Ch. 1) Protocol Architecture (Ch. 2) Data Transmission (Ch. 3) Guided and Wireless Transmission (Ch. 4) Signal Encoding Techniques (Ch. 5) Digital Data Communication Techniques (Ch. 6) Data Link Control (Ch. 7) Multiplexing (Ch. 8) COE 341 – Dr. Marwan Abu-Amara 3

Agenda n n Introduction Communications Model q q n n Main blocks and functionality

Agenda n n Introduction Communications Model q q n n Main blocks and functionality Communication Tasks Data Communication Networking q Wide Area Networks n n q Circuit switching Packet switching Frame Relay ATM Local Area Networks COE 341 – Dr. Marwan Abu-Amara 4

Introduction n n Fundamental purpose of communications system is exchange of data between 2

Introduction n n Fundamental purpose of communications system is exchange of data between 2 parties 3 general areas: q Data Communications (main concern of COE 341) n n q Networking n n q Transmission of signals in reliable & efficient manner Covers signal transmission, transmission media, signal encoding, interfacing, data link control, multiplexing Covers technology & architecture of communication networks Divided into LANs & WANs Protocols COE 341 – Dr. Marwan Abu-Amara 5

Simplified Communications Model - Diagram COE 341 – Dr. Marwan Abu-Amara 6

Simplified Communications Model - Diagram COE 341 – Dr. Marwan Abu-Amara 6

A Communications Model n Source q n Transmitter q n Carries data Receiver q

A Communications Model n Source q n Transmitter q n Carries data Receiver q n Converts data into transmittable signals (modulation, encoding, …) Transmission System q n Generates data to be transmitted Converts received signal into data (opposite to “Transmitter” role) Destination q Takes incoming data COE 341 – Dr. Marwan Abu-Amara 7

Communications Tasks Transmission system utilization Addressing Interfacing Routing Signal generation Recovery Synchronization Message formatting

Communications Tasks Transmission system utilization Addressing Interfacing Routing Signal generation Recovery Synchronization Message formatting Exchange management Security Error detection and correction Network management Flow control COE 341 – Dr. Marwan Abu-Amara 8

Simplified Data Communications Model n n n May involve buffering and/or encoding of digital

Simplified Data Communications Model n n n May involve buffering and/or encoding of digital data (Ch. 5) Modulated signal, s(t), matched to media (Ch. 3 & 4) Transmission Impairments: noise, distortion, etc. (Section 3. 3) Ideally received info, m’, should be identical to original input info, m (Ch. 7) If not, error correction may help restore m (Ch. 7) Else, retransmission is required (Ch. 7) COE 341 – Dr. Marwan Abu-Amara 9

Networking n Point to point communication not usually practical q q n Devices are

Networking n Point to point communication not usually practical q q n Devices are too far apart Large set of devices would need impractical number of connections (full connectivity of N nodes is N (N – 1) / 2) Solution is a communications network q q Wide Area Network (WAN) Local Area Network (LAN) COE 341 – Dr. Marwan Abu-Amara 10

Wide Area Networks n n n Large geographical area Rely in part on common

Wide Area Networks n n n Large geographical area Rely in part on common carrier circuits Alternative technologies q q Circuit switching Packet switching Frame relay Asynchronous Transfer Mode (ATM) COE 341 – Dr. Marwan Abu-Amara 11

Circuit Switching n n Dedicated communications path established for the duration of the conversation

Circuit Switching n n Dedicated communications path established for the duration of the conversation e. g. telephone network COE 341 – Dr. Marwan Abu-Amara 12

Packet Switching n n n Data sent out in sequence of small chunks (packets)

Packet Switching n n n Data sent out in sequence of small chunks (packets) of data Packets passed from node to node between source and destination Used for terminal to computer and computer to computer communications COE 341 – Dr. Marwan Abu-Amara 13

Frame Relay n n n Packet switching systems have large overheads to compensate for

Frame Relay n n n Packet switching systems have large overheads to compensate for errors Modern systems are more reliable Errors can be caught in end system Most overhead for error control is stripped out Variable-length packets (called frames) COE 341 – Dr. Marwan Abu-Amara 14

Asynchronous Transfer Mode (ATM) n n n Evolution of frame relay Combines circuit switching

Asynchronous Transfer Mode (ATM) n n n Evolution of frame relay Combines circuit switching & packet switching Little overhead for error control Fixed-length packets (called cells) Anything from 10 Mbps to Gbps Constant data rate while using packet switching technique COE 341 – Dr. Marwan Abu-Amara 15

Local Area Networks n Smaller scope q n n Building or small campus Usually

Local Area Networks n Smaller scope q n n Building or small campus Usually owned by same organization as attached devices Data rates much higher Usually broadcast systems Now some switched systems and ATM are being introduced COE 341 – Dr. Marwan Abu-Amara 16

LAN Configurations n Switched q Switched Ethernet n q q n May be single

LAN Configurations n Switched q Switched Ethernet n q q n May be single or multiple switches ATM LAN Fibre Channel Wireless q q Mobility Ease of installation COE 341 – Dr. Marwan Abu-Amara 17

Metropolitan Area Networks (MAN) n n Middle ground between LAN and WAN Private or

Metropolitan Area Networks (MAN) n n Middle ground between LAN and WAN Private or public network High speed Large area COE 341 – Dr. Marwan Abu-Amara 18

Networking Configuration COE 341 – Dr. Marwan Abu-Amara 19

Networking Configuration COE 341 – Dr. Marwan Abu-Amara 19