1. An Introduction to Computer Networking

2. Objectives Identify elements of a network
Describe several specific uses of a network
Distinguish between client/server and peer-to-peer networks
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CIS275

3. Networks and Standalone Computers
Group of computers and other devices connected by some type of transmission media
Networks enable users to share devices and data, collectively called a network’s resources
Standalone computer
Uses programs and data only from its local disks and is not connected to a network
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CIS275

4. Local and Remote Computers
Local computer
Computer on which user is working
Remote computer
Computer that user controls or works on via network connection
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CIS275

5. Simple peer-to-peer network
Computers communicate on single segment of cable and share each other’s data and devices
Simple example of a local area network (LAN)
Simple peer-to-peer network
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CIS275

6. Local Area Network (LAN)
Network of computers and other devices confined to relatively small space
LANs involving many computers are usually server-based
On a server-based network, special computers (known as servers) process data for and facilitate communication between other computers on the network (known as clients)
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CIS275

7. Networking Basics Workstation Client/server architecture
Computer that typically runs a desktop operating system and connects to a network
Client/server architecture
Networking model in which clients use central server to share applications, devices, and data
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CIS275

8. Networking Basics Client/server network Network operating system
Network based on client/server architecture
Network operating system
Special software designed to manage data and other resources on a server for a number of clients
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CIS275

9. Networking Basics
LAN with a file server
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CIS275

10. Advantages of Server-Based over Peer-to-Peer Networks
User login accounts and passwords can be assigned in one place
Access to multiple shared resources can be centrally granted
Servers are optimized to handle heavy processing loads and dedicated to handling requests from clients
Servers can connect more than a handful of computers
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CIS275

11. MANs and WANs Metropolitan area network (MAN) Wide area network (WAN)
Network connecting clients and servers in multiple buildings within limited geographic area
Wide area network (WAN)
Network that spans large distance and connects two or more LANs
The Internet is an example of a very intricate and extensive WAN that spans the globe
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CIS275

12. WAN
A simple WAN
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CIS275

13. Elements Common to All Server-Based Networks
Client
In addition to referring to a computer on the network, may also refers to human user of client workstation
Server
Workstation
Network interface card (NIC)
Enables workstation to connect to the network and communicate with other computers
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CIS275

14. Elements Common to All Server-Based Networks
Network operating system (NOS)
Host
Server that manages shared resources
Node
Client, server, or other device that can communicate over a network and that is identified by a unique identifying number, known as its network address
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CIS275

15. Elements Common to All Server-Based Networks
Topology: It is the physical layout of computer network
Commonly used network topologies are:
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CIS275

16. Elements Common to All Server-Based Networks
Protocol
Rules network uses to transfer data
Data Packets
The distinct units of data transmitted from one computer to another on a network
Addressing
Scheme for assigning unique identifying number to every workstation on network
The number that uniquely identifies each workstation and device on a network is its address
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CIS275

17. Elements Common to All Server-Based Networks
Transmission media
Means through which data are transmitted and received
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CIS275

18. How Networks Are Used Services Features provided by a network
File and print services
Communications services
Mail services
Internet services
Management services
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CIS275

19. Network Services File services Print services
Refers to capability of a server to share data files, applications, and disk storage space
Server that provides file services is called a file server
Print services
Allows printers to be shared by several users on a network
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CIS275

20. Network Services Communications services
Allow remote users to connect to a network
Remote user
Person working on a computer in a different geographical location from the LAN’s server
Communications server
Server that runs communications services
Also referred to as access servers and remote access servers
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CIS275

21. Network Services Mail services Internet services
Coordinate storage and transfer of between users on a network
Gateway
Combination of software and hardware enabling two different kinds of networks to exchange data
Internet services
Enable networks to communicate with the Internet
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CIS275

22. Network Services Management services
Centrally administer and simplify complicated management tasks on the network
Numerous services fall under category of network management
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CIS275

23. Important Management Services
Traffic monitoring and control
Traffic
Data transmission and processing activity taking place on a computer network at any given time
Segment
Part of LAN that is logically separated from other parts of LAN and that shares fixed amount of traffic capacity
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CIS275

24. Important Management Services
Load balancing
Distributing process activity evenly across a network so that no single device is overwhelmed
Hardware diagnosis and failure alert
Determining when a network component fails and automatically notifying network administrators through or pager
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CIS275

25. Important Management Services
Asset management
Collecting and storing data on number and types of software and hardware assets in an organization’s network
License tracking
Determining how many copies of a single application are currently in use on a network
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CIS275

26. Important Management Services
Security auditing
Evaluating what security measures are currently in force and notifying network administrator if a security breach occurs
Software distribution
Automatically transferring data file or program from the server to a client on the network
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CIS275

27. Important Management Services
Address management
Centrally administering a finite number of network addresses for an entire LAN
Backup and restoration of data
Backing up
Copying critical files to a secure storage area
Restoring
Retrieving data if original files are lost or deleted
11/18/2018
CIS275