1. Data Networking Fundamentals
Unit 7
Modified by: Brierley
9/13/2018

2. Objectives
Discuss basic networking concepts - elements common to client-server
Provide examples of multiple network services
Describe differences between LANs, MANs, and WANs
Understand the function of each layer of the OSI model
Describe the purpose of protocols and recognize core protocols and addressing scheme for the TCP/IP protocol suite
Modified by: Brierley
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3. Terminology
Standalone workstation - a workstation not connected to a network. Relies on its own hard disk for data storage and applications. A Personal computer (PC).
Client - a workstation or PC connected to a network. The person whose workstation is part of a network may also be called a “client”, or more informally a “user”.
Servers - store shared data and programs on their hard disks. They perform management functions - such as determining a user’s access to certain applications, data and services.
Client-server – an architecture that uses a server to enable clients with sharing data storage space, networked devices and services.
Modified by: Brierley
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4. Terminology
Modified by: Brierley
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5. Requirements for Connectivity
Modified by: Brierley
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6. Requirements for Communications
Node - any device (a server, client, printer, mobile device, etc.) that can receive messages across a network. To receive data, each node must have a unique address.
Protocol – a set of rules
Modified by: Brierley
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7. Servers
Server - A computer on the network that manages shared resources.
Redundancy – Replica - Using more than one component to guard against failure.
Network operating system (NOS) - software that can manage data, users, groups, security, and applications on the network.
Modified by: Brierley
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8. How Networks are Used
The purpose of using networks is to share services - programs, data, and devices - known as resources.
Network services can be categorized as follows:
File services
Print services
Communication services
Mail services
Internet services
Management services
Modified by: Brierley
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9. LANS, MANS, and WANS
Local area network (LAN) - a network of computers and other devices that is limited to a relatively small area, such as a building, rooms, or office.
Connectivity device - when multiple networks or multiple parts of one network need to communicate with each other, this device is used to exchange data between them, ie hubs, routers and switches.
Hub – forward messages to all its connected devices. Hubs today are Legacy replaced with switches.
Modified by: Brierley
9/13/2018

10. LANS, MANS, and WANS
Metropolitan area network (MAN) - a network that connects LANs between multiple buildings in a region.
Wide area network (WAN) - a network that connects geographically distinct LANs, MANs, CANs, PANs – wired and/or wireless
Modified by: Brierley
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11. LANS, MANS, and WANS
Modified by: Brierley
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12. LANS, MANS, and WANS
Modified by: Brierley
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13. LANS, MANS, and WANS
Modified by: Brierley
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14. LANS, MANS, and WANS
Modified by: Brierley
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15. The Internet
The Internet is a unique WAN in size, and diversity. It is used to:
Transmit confidential information between two offices or it may transmit public information to anyone who requests it.
Connect users from around the globe, the Internet relies on a hierarchical structure of connection points, just as the PSTN relies on a hierarchy of LEC and IXC switches.
Connect to Internet Service Providers (ISP) – Companies that operates a network and provides consumers links to the Internet.
Modified by: Brierley
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16. The Internet
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17. The Internet
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18. The OSI Model ( 7 layers) 7 6 5 4 3 2 1 Modified by: Brierley
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19. Application Layer LAYER 7
Provides interfaces to software that enable applications to use network services.
Application program interface (API) - A set of instructions that allows a program to interact with an operating system.
Modified by: Brierley
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20. Presentation Layer LAYER 6
Establishes translation between the application and the network.
Data becomes formatted in a schema that identifies the application.
Encryption - A mathematical schema executed by both the sender and receiver of the payload for security.
Modified by: Brierley
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21. Session Layer LAYER 5 Functions include:
Establishing and keeping alive the communications link for the duration of the session
Synchronizing the dialog between the two nodes
Determining whether communications have been cut off and establish where to restart transmission
Modified by: Brierley
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22. Transport Layer
LAYER 4
Responsible for ensuring that data is transferred from point A to point B reliably, in the correct sequence, and without errors.
Handles flow control, a method of gauging the appropriate rate of transmission.
Segmentation - the process “chunking up” the Payload when moving data to the network layer into smaller units.
Modified by: Brierley
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23. Network Layer
LAYER 3
Translates network addresses into their physical counterparts and decide how to route data from the sender to the receiver.
Addressing is handled at the Network layer.
Modified by: Brierley
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24. Data Link Layer
LAYER 2
Controls communications between the Network layer and the Physical layer.
Frame - a structured package for moving data that includes not only data, or "payload," but also the sender’s and receiver’s network addresses, and error checking and control information.
Modified by: Brierley
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25. Data Link Layer
Modified by: Brierley
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26. Data Link Layer
Modified by: Brierley
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27. Physical Layer
LAYER 1
Generates and detects voltage (pulses of light) to transmit and receive signals representing data.
Sets the data transmission rate and monitors data error rates.
Physical network problems, cut cable, disconnected cable, improperly defined interface
Modified by: Brierley
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28. Applying the OSI Model 7 6 5 4 3 2 1
Modified by: Brierley
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29. Applying the OSI Model 7 6 5 4 3 2 1
Modified by: Brierley
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30. Applying the OSI Model 7 6 5 4 3 2 1
Modified by: Brierley
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31. TCP/IP Compared to the OSI Model
The TCP/IP model includes the following:
Layer 4 - Application layer - provides authentication and compression services, and is roughly equivalent to the Application, Presentation, and Session layers of the OSI model.
Layer 3 - Transport layer - roughly corresponds to the Transport layer of the OSI model.
Layer 2 - Network layer - equivalent to the Network layer of the OSI model.
Layer 1 - Link layer - roughly equivalent to the Data Link and Physical layers of the OSI model.
Modified by: Brierley
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32. The OSI and TCP/IP Models7 6 5 4 3 2 1 4 3 2 1
Modified by: Brierley
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33. Internet Protocol
Belongs to the Network layer of the OSI model and to the Internet layer of the TCP/IP model. It provides information about how and where data should be delivered.
Datagram - the IP portion of a data frame, acts as an envelope for data and contains information for routers to transmit data between networks.
IP is an unreliable, connectionless protocol, which means that it does not guarantee delivery of data.
Modified by: Brierley
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34. Internet Protocol
Modified by: Brierley
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35. Transmission Control Protocol (TCP)
Modified by: Brierley
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36. Transmission Control Protocol (TCP)
Modified by: Brierley
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37. The TCP/IP Application Layer Protocols
Dynamic Host Configuration Protocol (DHCP) – automatically assigns a unique Network layer (IP) address to devices that access the network.
File Transfer Protocol (FTP) - sends and receive files between hosts.
Hypertext Transfer Protocol (HTTP) - Enables Web browsers to issue requests to Web servers and interpret the response.
Modified by: Brierley
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38. The TCP/IP Application Layer Protocols
Simple Mail Transfer Protocol (SMTP) - Responsible for moving messages from one mail server to another over the Internet.
Telnet - a terminal emulation protocol used to log on to remote hosts to issue configuration instructions.
Modified by: Brierley
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39. Addressing in TCP/IP
Modified by: Brierley
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40. Addressing in TCP/IP
To view your current IP information on a Windows , XP, Vista, 7 Windows XP Operating System:
Click Start, then click Run. The Run dialog box opens.
In the Open text box, type cmd, then click OK. The Command Prompt window opens.
At the DOS prompt, type ipconfig /all.Your workstation’s IP address information is displayed
Type exit, then press Enter to close the Command Prompt window.
Modified by: Brierley
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41. Addressing in TCP/IP
Modified by: Brierley
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42. Data Networks Summary
Workstations – client computers on a network share data, programs, and devices through a central computer called a server.
Servers - using a server to enable client computers to share data storage space and devices constitutes a client-server network.
Reference Models
OSI and TCP/IP
Modified by: Brierley
9/13/2018

43. The OSI and TCP/IP Models7 6 5 4 3 2 1 4 3 2 1
Modified by: Brierley
9/13/2018