Introduction to Data Communications and Networking

Lesson Objectives - the students should be able to:

• Define Data Communications
• Enumerates and understand the functions of each components of Data Communications
• Understand Data Representations and Data Flow
• Define Networks
• Understand Distributed Processing, Network Criteria, Physical Structures, Network Models
• Enumerates the Categories of Network
• Learn Interconnection of Network: Internetwork
• Define the Internet
• Know the brief history of Internet
• Define Protocols and Standard

Lecture on Introduction to Datacommunication and Networking PPT

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• Data Communications Course Outline

Definition of Terms

• Data communication is the transfer of data from one device to another via some form of transmission medium.
• A data communications system must transmit data to the correct destination in an accurate and timely manner.
• A network is a set of communication devices connected by media links.
• Topology refers to the physical or logical arrangement of a network. Devices may be arranged in a mesh, star, bus, or ring topology.
• An internet is a network of networks.
• The Internet is a collection of many separate networks.
• TCP/IP is the protocol suite for the Internet.
• A protocol is a set of rules that governs data communication; the key elements of a protocol are syntax, semantics, and timing.
• Standards are necessary to ensure that products from different manufacturers can work together as expected.
• Forums are special-interest groups that quickly evaluate and standardize new technologies.
• A Request for Comment (RFC) is an idea or concept that is a precursor to an Internet standard.

Five Components of Data Communications

• message
• sender
• receiver
• medium
• protocol

Different forms of information

• Text
• numbers
• images
• audio
• video

Data flow between two devices

• Simplex - Only one of the two devices on a link can transmit; the other can only receive.
• Half-duplex - Each station can both transmit and receive, but not at the same time.
• Full-duplex - Both stations can transmit and receive simultaneously.

Three criteria for an effective and efficient network

• Performance - Measured in many ways, including transit time and response time. It is evaluated by two networking metrics: throughput and delay.
• Reliability - Measured by the frequency of failure, the time it takes a link to recover from a failure, and the network's robustness in a catastrophe.
• Security - Include protecting data from unauthorized access, protecting data from damage and development, and implementing policies and procedures for recovery from breaches and data losses.

Types of Connection (Line configurations)

• Point-to-point connection - two and only two devices are connected by a dedicated link.
• Multipoint connection - three or more devices share a link.

Four Basic Topologies

• Mesh - Every device has a dedicated point-to-point link to every other device.
• Star - Each device has a dedicated point-to-point link only to a central controller, usually called a hub.
• Ring - Each device has a dedicated point-to-point connection with only the two devices on either side of it.
• Bus - One long cable acts as a backbone to link all the devices in a network.

Network Categories

• Local area network (LAN) - data communication system within a building, plant, or campus, or between nearby buildings.
• Metropolitan-area network (MAN) - data communication system covering an area the size of a town or city.
• Wide area network (WAN) - data communication system spanning states, countries, or the whole world.

Internet service providers (ISPs)

• Local
• Regional
• National
• International

Key Elements of a Protocol

• Syntax - structure or format of the data, meaning the order in which they are presented.
• Semantics - the meaning of each section of bits.
• Timing - refers to two characteristics: when data should be sent and how fast they can be sent.

Some of the organizations involved in standards creation

• ISO
• ITU-T
• ANSI
• IEEE
• EIA

Note: Lets see how well you the understand the first chapter and try answering the Multiple Choice Questions here.

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credit: Behrouz A. Forouzan©2013 www.FroydWess.com

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