Computer Networks Foundation

244 views
178 views

Published on

Describing basic networking concepts, topologies, the OSI model, and the media used to physically connect a network.

Published in: Technology, Education
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
244
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
7
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Computer Networks Foundation

  1. 1. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge)
  2. 2. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge)
  3. 3. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge) Managing and Leading a Virtual Team Introductory concepts @ OxfordCambridge.Org all for free and free for all. The information gathered here is under KeyPoints format and may be use: - Either to give the reader an overview before deciding for a full scale study of the topic. - Or act as a study guide for learners in expanding their knowledge on the given topic. Some recommendations, perhaps: - Identify each KeyPoint on which you feel a need to expand your knowledge, - Choose a good book /ebook or academic journal and Internet info. - And then work towards gaining that knowledge, at your own pace. Please enjoy!
  4. 4. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) Computer Networks Foundation – Summary. ☺ A network consists of two or more computers connected together which share resources such as data, printers, and an Internet connection. ☺ The term "networking" refers to the sharing of resources on a network. ☺ Local area networks (LANs) are one of the most widely used types of networks. ☺ The Open System Interconnection (OSI) model was developed in 1984 by the International Organization for Standardization (ISO) to resolve the problem of incompatible networks.
  5. 5. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge) Computer Networks Foundation - Aim of publication. To introduce the reader or the learner to basic networking concepts, topologies, the OSI model, and the media used to physically connect a network.
  6. 6. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) Computer Networks Foundation - Learning Objectives. ☺ After developing the KeyPoints outlined in this publication, you should mainly be able to:  identify the primary components of a network and distinguish between the two main network architectures.  distinguish between the main types of networks  distinguish between the OSI reference model and the TCP/IP stack.  distinguish between common network categorizations and identify the characteristics of data encapsulation.  identify the major components of a network PC and list the resources required to install a NIC.  identify the functions, features, and operation of network devices used at different layers of the OSI model.  distinguish between different network topologies  match network devices to their functions and distinguish between different network topologies.  differentiate between types of network media.  recognize the types of cable connectors used in modern networks.  determine the most appropriate network tool to use in a given scenario.
  7. 7. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) *** About the Structure and Flow of our Presentations ***
  8. 8. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge) Computer Networks Foundation - Sections List.  (Section 1) Networking basics.  (Section 2) Networking devices and topologies.  (Section 3) Physical media.
  9. 9. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge) (Section 1) Networking basics – HighPoints.  Networking overview.  Types of networks  The OSI model  Understanding basic networking concepts.
  10. 10. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 1) HighPoints: Networking overview. ☺ A network is made up of two or more computers linked together. ☺ Networking is the term used to refer to the sharing of resources on the network. ☺ Networks can vary in size from local area networks (LANs), which are contained in a building, to wide area networks (WANs), such as the Internet. ☺ The three primary components of a network are a server, a workstation, and a host. ☺ Two of the most common network types are client/server and peer-to-peer. ☺ Peer-to-peer networks have no centralized authority while client/server networks are managed from a centralized point. ☺ Client/server networks have several advantages over peer-to-peer networks such as ease of management and better security.
  11. 11. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 1) HighPoints: Types of networks. ☺ A local area network (LAN) is used to connect workstations, servers, and peripheral devices, such as printers, together. ☺ It is confined to a small area, usually within a building. ☺ A wide area network (WAN) covers a large geographic area. ☺ WANs can be public or private. WANs have slower connection speeds than LANs. ☺ WANs use routers, WAN switches, and modems. ☺ The Internet is an example of a global WAN. ☺ A metropolitan area network (MAN) extends across a city or a large suburban area. ☺ A MAN develops when two or more LANs are connected together. ☺ An intranet is a private network contained inside a company. ☺ It can contain many LANs linked together. ☺ It allows employees to share information and access company resources. ☺ An extranet is part of a company's intranet that can be accessed by anyone outside the company.
  12. 12. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 1) HighPoints: The OSI model. ☺ The Open System Interconnection (OSI) reference model was developed by the International Organization for Standardization (ISO) to correct the problem of incompatible network communications. ☺ It is a reference model that describes how information is exchanged between points on a network. ☺ The OSI model is divided into seven layers - these are the application, presentation, session, transport, network, data- link, and physical layers. ☺ Some of the advantages of layering network functions include accelerating evolution, reducing complexity, and standardizing network component interfaces. ☺ Encapsulation refers to the process of packaging information before it is transmitted. ☺ Thus, encapsulation occurs in descending order from the application layer through to the physical layer. ☺ Headers and trailers are placed around the data as it passes through each layer.
  13. 13. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 1) HighPoints: The OSI model (continues). ☺ Data packets always travel from source to destination on a network. ☺ They can only travel on a network if each layer of the OSI model at the source communicates with its peer layer at the destination. ☺ This form of communication is known as peer-to-peer communication. ☺ Another open standard traditionally applied to the Internet is the Transmission Control Protocol/Internet Protocol (TCP/IP) stack. ☺ Like the OSI model, it uses layering and is comprised of the application, transport, Internet, and network access layers. ☺ The TCP/IP and OSI models are similar in a number of ways. ☺ Both models have application, network, and transport layers, and they both deal with packet-switched technology.
  14. 14. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 1) HighPoints: Understanding basic networking concepts. ☺ There are different categorizations of networks used to identify their size, structure, and purpose. ☺ A WAN is a network that covers a large geographic area and can be used to link together the worldwide locations of a corporation. ☺ A MAN covers a large city or suburban area and consists of several LANs connected together. ☺ A LAN is a high-speed, low error data network that is confined to a small area, usually within a building. ☺ Data encapsulation occurs when data is systematically and consistently packaged before it is sent over the network. ☺ In the encapsulation process, the application layer contains the L7 header, the presentation layer contains the L6 L7 headers, and the session layer contains the L5 L6 L7 headers. ☺ A data packet contains the L4 L5 L6 L7 header at the transport layer, the L3 L4 L5 L6 L7 header at the network layer, and the L2 L3 L4 L5 L6 L7 header at the data-link layer. ☺ Bits are associated with the physical layer, frames with the data-link layer, packets with the network layer, and segments with the transport layer.
  15. 15. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 2) Networking devices and topologies – HighPoints. ☺ Components of a network PC. ☺ Network devices. ☺ Network topologies. ☺ Identifying network devices and topologies.
  16. 16. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 2) HighPoints: Components of a network PC. ☺ To enable network connectivity, a computer uses components such as the central processing unit (CPU), bus, drives, cards, ports, and memory. ☺ A computer is composed of drives, the CPU, expansion slots, a bus, a motherboard, and a backplane. ☺ A network interface card (NIC) is a device that enables a computer to communicate with a network. ☺ Selecting a NIC depends on the type of network, cable, and expansion slot on your computer. ☺ If installing a NIC, you should be able to configure it, perform its diagnostics, and resolve hardware conflicts.
  17. 17. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 2) HighPoints: Network devices. ☺ Hubs, switches, and routers are all networking devices used to connect networks. ☺ Networking devices operate chiefly at the lower three layers of the Open System Interconnection (OSI) model. Layer 1 devices, such as repeaters and hubs, are used to propagate network signals at bit level. ☺ Network Interface Cards (NICs), bridges, and switches are OSI layer 2 devices used to transmit data. ☺ Every NIC has a unique Media Access Control (MAC) address that is used to identify its host to switches and bridges. ☺ These devices forward traffic based on the host's MAC address. ☺ Routers use layer 3 addresses to transmit packets between networks. ☺ Multilayer switches use layer 3 network addresses (IP) and layer 2 MAC addresses to manage packet traffic. ☺ Hardware-based layer 3 routing functions provide faster operation than software versions. ☺ Gateways are used to connect disparate network environments. ☺ Firewalls and AAA (authentication, authorization, and accounting) servers protect networks from unauthorized attacks and unauthorized access.
  18. 18. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 2) HighPoints: Network topologies. ☺ A network topology describes how the network is laid out, and how data is transmitted on it. ☺ The physical topology defines the physical arrangement of the devices and cables on a network. ☺ The logical topology defines the paths used by information to flow through a network. ☺ A network can have the same logical and physical topologies, but this is not always the case. ☺ Typical network topology types commonly used include the bus, star, extended star, ring, full mesh, and partial mesh topologies.
  19. 19. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 2) HighPoints: Identifying network devices and topologies. ☺ Commonly used network devices include repeaters, hubs, NICs, switches, and routers. ☺ Hubs are used as network concentration points, and a repeater regenerates signals so that they can cover greater distances along a cable. ☺ A bridge creates two or more LAN segments, with each segment being a separate collision domain. ☺ A router is an internetworking device that matches information in the routing table with the destination IP address of the data and forwards data packets between networks. ☺ Networks can have different topologies. ☺ A network topology describes how the network is laid out, and how data is transmitted on it.
  20. 20. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 3) Physical media – HighPoints ☺ Network cabling and wireless media. ☺ Network cable connectors. ☺ Network installation tools. ☺ Connecting the network.
  21. 21. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 3) HighPoints: Network cabling and wireless media. ☺ Twisted pair cable is a common cable type - it is available as shielded twisted pair (STP) or unshielded twisted pair (UTP). ☺ STP cable combines the techniques of twisting wires and shielding. UTP cable is a copper wire-based cable used in a variety of networks. ☺ Coaxial cable operates over relatively large distances, and transmits data at speeds of up to 100 Mbps. ☺ Installing coaxial cable is more expensive than installing twisted pair cable. ☺ Fiber optic cable transmits bits in the form of modulated light data. ☺ Light is refracted along the cable and can go around bends. ☺ Fiber optic cables are available as single-mode or multimode cable. ☺ Wireless signals are radio frequencies and infrared waves that can travel through air. ☺ They have been a growth area in network communications.
  22. 22. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 3) HighPoints: Network cable connectors. ☺ Cable connectors differ in modern networks depending on the cable type. ☺ Unshielded twisted pair (UTP) cable normally uses a Registered Jack (RJ) connector, which is attached using a crimper. ☺ This can be an RJ-11 or an RJ-45. By contrast, coaxial cable often uses Attachment Unit Interface (AUI)/DB-15, Bayonet Neill-Concelman connector (BNC) or F-Type connectors. ☺ There are a number of fiber optic cable connectors available also--the one you choose depends on what you are using it for. ☺ The most common types are Subscriber Connector (SC), Straight Tip (ST), Local Connector (LC), and MT-RJ. ☺ Digital devices can be connected using the Institute of Electrical and Electronics Engineers (IEEE) 1394 standard--it supports data transfer rates of up to 400Mbps (using IEEE 1394a), or 800Mbps (using IEEE 1394b). ☺ The products that support the standard are known by various names, but two of the most popular products are FireWire (which is made by Apple), and i.link.
  23. 23. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 3) HighPoints: Network installation tools. ☺ A patch panel is a centralized wiring point for multiple devices on an unshielded twisted pair (UTP) network. ☺ You use a patch panel to connect the cables going to the network hub with the cables going to the workstations. ☺ You connect components to a patch panel using patch cables and the total segment length of the network includes the patch cables at both ends and the drop cable between. ☺ Wire crimpers and punchdown tools can be used to connect network cables to connectors and patch panels. ☺ There are a number of different network testing tools and the type you choose depends on the type of cabling in your network, cost, and what you are testing it for. ☺ The most popular types of testing tools are the wire map tester, continuity tester, tone generator, optical loss test set (OLTS), and the multifunction cable tester. ☺ There are also fiber optic patch panels to take into consideration.
  24. 24. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 3) HighPoints: Connecting the network. ☺ Understanding the types of media that can be used within a network provides you with a better understanding of how networks function, and allows you to select the most suitable means of connecting your network devices. ☺ Coaxial cable is able to cover 450 meters or more and is resistant to electromagnetic interference and supports 10 to 100 Mbps. ☺ Thicknet coaxial cable can be used to connect the head office to the branch office situated less than half a kilometer away. ☺ Thinnet coaxial cable is especially useful for installations that require the cable to make many twists and turns. ☺ UTP is the cheapest media type – it is easy to install, and can cover a distance up to 100 meters. ☺ UTP has the ability to reduce interference and is compatible with most of the major networking architectures. ☺ STP (shielded twisted pair) is more resistant to EMI (electromagnetic interference) than UTP.
  25. 25. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) (Section 3) HighPoints: Connecting the network (continues). ☺ Wireless media allow you to exchange data with devices where no physical medium exists. ☺ For that matter, wireless communication can use RFs (radio frequencies) to transmit data between devices on a LAN. ☺ A wireless hub is used for signal distribution as the access point where PCs and laptops connect to the network. ☺ RJ-45 connectors are used to connect the workstations on each floor to the workgroup switch for that floor. ☺ Fiber optic cable has data exchange rates of up to 100 Gbps and can cover distances well over 100 meters. ☺ Multimode fiber optic can support cables for up to two kilometers only, whereas the maximum cable length of single-mode cable is 60 kilometers. ☺ ST, LC, and MT-RJ are fibre optic cable connectors that can be used to connect an organization workgroup network switches between floors.
  26. 26. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford) Computer Networks Foundation – Conclusion. ☺ At this point you should be familiar with the following:  identifying the primary components of a network and distinguish between the two main network architectures.  distinguishing between the main types of networks.  characteristics of data encapsulation.  functions of common network devices.  characteristics of physical topologies.  potential future developments in wireless services.  identifying the characteristics and benefits of the principal and enabling technologies of 4G.  choosing a specific network media type for a given scenario.  specifications of the different media that are available..  different cable connector types available.
  27. 27. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Harcourt Hill, West Oxford)
  28. 28. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge)
  29. 29. Contact Email Design Copyright 1994-2014 © OxfordCambridge.OrgCurricula/Curriculum (This picture: Trinity College, Cambridge) We shall always be on SlideShare!

×