Lecture Week 8: Network Technology PDF

FDITC001 Computing Principles Lecture Week 8: Network Technology  FDITC001 Computing Principles Learning Outcomes At the end of this lesson, students will be able to: ▪ describe network, nodes...

FDITC001 Computing Principles Lecture Week 8: Network Technology  FDITC001 Computing Principles Learning Outcomes At the end of this lesson, students will be able to: ▪ describe network, nodes and use of the communication systems ▪ explain all the fundamentals of computer network ▪ describe network architectures (topologies and strategies) ▪ explain network components, protocols and communication channels ▪ discuss the organization issues related to Internet technologies and network security.  FDITC001 Computing Principles Introduction ▪ A computer network - a set of two or more computers connected to each other. Once joined together these computers can share files together and share devices like printers which are on the same network. ▪ The network is connected to wires, either physical wires or wireless links, so the various separate devices (known as nodes) can "talk" to one another and exchange data. ▪ Nodes refer to any devices that are connected to the network system.  FDITC001 Computing Principles Network Communication Systems  FDITC001 Computing Principles How Computer Network Help Us? Communication - people can communicate with others all over the world at a very low-cost using e-mail, chat, video conferencing and SMS. Sharing Resources - in a network, resources such as printers, scanners, fax machines and modems can be shared among the users. Sharing Software - application programs or apps are generally stored on the central computer server and are accessible to any workstation connected to this network. Sharing Data - users on a network can access data stored on other computers and on the internet. Known as Databases. Cloud sharing.  FDITC001 Computing Principles Fundamentals of Networking ▪ Networks are divided up into fundamental parts which include types, topologies, designs and components. These parts will all have a bearing on which network type companies will choose as the needs of each business is different. Network Network Network Types Network Design Topologies Components PAN Star Client Server NIC & MODEM LAN Ring Peer-to-Peer Hub / Switch MAN Bus (P2P) Routers WAN Mesh Cabling Hybrid Network Protocol  FDITC001 Computing Principles Network Types / Classifications Wide Area Network (WAN) covers the largest geographical area of all networks ex: Internet. Metropolitan Area Network (MAN) covers whole cities or large towns. MAN is larger than a LAN. Local Area Network (LAN) covers limited geographical area such as home, school, computer lab or office building. Personal Area Network (PAN) used for communication among computer devices, including mobiles phones, laptops and gaming consoles in a limited area.  FDITC001 Computing Principles LAN Network Topology ▪ Network Topology - physical arrangement of the network so that the LAN network can perform without experiencing any problems. ▪ It is must be organised into strict patterns (topology) on how the cables and devices are connected to the nodes. A network can use a single topology or a mixture of topologies. ▪ Topology is important because it resolves the conflict that occurs when two or more computers on the network attempt to transmit at the same time. ▪ The common topologies are Star, Ring & Bus. Other topologies Mesh and Hybrid.  FDITC001 Computing Principles Star & Bus Topology Star - Each device connected Bus - all devices share a directly to a central network common backbone where all switch / hub. communications travel along. Most widely used network If the backbone cable fails, topology today. the entire network effectively If the hub fails, however, the goes down. entire network also fails.  FDITC001 Computing Principles Ring & Mesh Mesh - Does not use a specific physical Ring – each device is connected layout but requires that each node have to 2 other devices forming a ring. more than one connection to other Message is passed around the nodes. ring until it reaches the Practically used in wireless network. intended destination. If a path between two nodes is disrupted, Suitable for small offices (less data can be rerouted around the failure than 10 computers). using another path.  FDITC001 Computing Principles Hybrid Topology Hybrid refers to integrating two or more different topologies (i.e. Star and Ring) This combination of topologies is done according to the requirements of the company. While this topology has positives such as reliability and effectiveness, it is costly and complex in design and infrastructure.  FDITC001 Computing Principles Considerations when choosing a topology A linear bus network is the cheapest option to install Cost however it is not considered the most reliable. The most common cable in schools is unshielded Cable type twisted pair, which is most often used with star topologies. Length of The linear bus network uses shorter lengths of cable. cable needed With a star topology, expanding a network is easily Future growth done by adding another switch.  FDITC001 Computing Principles Network Design ▪ Sometimes called "Network Strategies“. Network Design focuses on the configuration and functionality of the network. ▪ It is the way of coordinating the sharing of information and resources within a network type. ▪ There are two main designs: Client/Server – made up of one or more servers and clients (any type of computer). Peer to Peer (P2P) - all nodes have equal authority and can act as both client and server.  FDITC001 Computing Principles Client-Server Network ▪ More efficient and suitable for large company. ▪ All files are stored in a central location. ▪ It requires network operating system (NOS) to monitor and control network activities. ▪ Peripheral devices are controlled centrally with good security system. ▪ Easier to do data backup and do not slow down with heavy use. ▪ But, costly to maintain, requires a network manager to monitor. ▪ Server failure leads a lot of disruptions.  FDITC001 Computing Principles P2P Network ▪ Share files without a file server; does not require Network OS ▪ Best used for home or small offices with no more than 10 computers ▪ Are easy and inexpensive (or free) to set up ▪ Can be slow if there are too many users. ▪ Security is not strong. ▪ Data is not centralized.  FDITC001 Computing Principles Components of a Computer Network Components Purpose / Function(s) Image Network All PC’s connected to a network must be installed with NIC. interface card It is an expansion board that provides a connection between (NIC) the computer and the network. Allow connection between two or more networks. Determine Routers the best route to transmit data. Filter and forward data between nodes. Switches Are similar to routers but work within a single network. Joins multiple computers together in a single network. Does Hub not manage traffic between the connections.  FDITC001 Computing Principles Components of a Computer Network ▪ Modem – modulator-demodulator Modulation - is the process of converting from digital to analog Demodulation - is the process of converting from analog to digital ▪ Transfer rate – speed in which modems transfer data usually measured in bps (bits per second) Kbps, Mbps or Gbps etc.  FDITC001 Computing Principles Cabling / Communication media ▪ A communication media is the medium used to transport information from one network device to another. There are two types wired and wireless. ▪ Wired Channels: Ethernet is extremely common and has several types. The higher the cable rating i.e. Cat5, Cat6, Cat7, the higher the bandwidth (speedier the connection) the cable can support. Fiber optic is very popular media recently and many homes are already using this cable, but it is more expensive.  FDITC001 Computing Principles Cabling / Communication media ▪ In wireless, data travel through air. ▪ Most widespread used channels are radio signals and microwaves. ▪ RF signals are sent and received by a transceiver (a combination of a transmitter and a receiver) that is equipped with an antenna. ▪ Microwaves - (the waves themselves, not your oven!) provide another option for transporting data wirelessly. ▪ Microwaves are electromagnetic signals that can be aimed in a single direction and have more carrying capacity than radio waves.  FDITC001 Computing Principles Typical Home Network (Wireless)  FDITC001 Computing Principles Software: Transmission Protocol ▪ For data transmission to be successful, sending and receiving devices must a follow as set of rules for the exchange of information. These rules for exchanging the data between computers are known as protocols. ▪ TCP/IP (Transmission control protocol/Internet protocol) - most widely used rules that governs how data is broken into packets, configured, transmitted and reassembled at the destination computer. ▪ HTTPS – Hypertext Transfer Protocol Secure - widely used to protect the transfer of sensitive data especially for Internet services. ▪ Each computer is identified with unique IP (Internet Protocol) address. DNS – Domain Name Servers – used to translate domain names into IP address.  FDITC001 Computing Principles Organizational Networks ▪ Many organization today employ Internet technologies to support effective communication within and between organizations using: ▪ Intranet Private network within an organization Works like the Internet Include electronic telephone directories, e-mail addresses, employee benefit information, internal job openings, etc. ▪ Extranet Private network that connects organizations Works like the Internet, but provides suppliers and other trusted partners with limited access to the organization’s networks  FDITC001 Computing Principles Intranet, Extranet, Firewall  FDITC001 Computing Principles Network Security Commonly used technologies by organizations to ensure network security: ▪ Firewall Hardware and software controls access to network Proxy server provides pass-through access Protects against external threats ▪ Intrusion detection system (IDS) Works with firewall to protect organization's network Analyzes all incoming and outgoing network traffic ▪ Virtual private network (VPN) – operates over Internet Creates a secure private network connection between your computer and the organization using ISP connection. Access to a VPN is usually by invitation only (special id and password to access).  FDITC001 Computing Principles Ways to protect your Network ▪ Install all updates - make sure that all your devices have the latest operating system, web browsers and security software. his is the best defense against viruses, phishing and other online threats. ▪ Protect your router - change the name and password of your router regularly. Use strong password. ▪ Plug and scan - USBs and other external drive devices can be infected by viruses. Use your security software to scan them. ▪ Back it up - Protect your valuable work, music, photographs and other digital information by making an electronic copy and storing it safely. ▪ Use secure sites – while accessing banking sites / online, use sites with https instead of http.  FDITC001 Computing Principles Advantages & Disadvantages of Networking Advantages Disadvantages Hardware cost reduction Loss of autonomy / power Sharing of information, data, Lack of privacy and applications Security threats Data management Loss of productivity centralization (client/server) Linking of people  FDITC001 Computing Principles Lecture Activity ▪ Name and briefly describe the 4 different types of networks. ▪ What is a network topology? ▪ What is a wireless network and why is it very popular in- home network today? ▪ Why topology is very important in a LAN? ▪ List three drawbacks of P2P strategy. ▪ Why wired network is more secured than wireless connection? 27