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ASSIGNMENT 1 FRONT SHEET
Qualification BTEC Level 5 HND Diploma in Computing Unit number and title Unit 2: Networking Infrastructure Submission date Date Received 1st submission Re-submission Date Date Received 2nd submission Student Name Ngô Thanh Tùng Student ID GCH Class GCH1104 Assessor name Ha Trong Thang Student declaration I certify that the assignment submission is entirely my own work and I fully understand the consequences of plagiarism. I understand that making a false declaration is a form of malpractice. Student’s signature Tung Grading grid
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I. Discuss the benefits and constraints of different network types and standards (P1)
1. Definition of network In information technology, a network is defined as a group of two or more devices that can communicate either by cable or wireless connection. There is no hierarchy in this network, both participants have the same privileges. Each computer has access to the other’s data and can share resources. The scale of a network can range from a single pair of devices sending data back and forth, to massive data centers and even the global Internet. They share the same purpose of giving the user the ability to share information and resources. Networks may be used for:
- Communications such as email, instant messaging, chat room, etc.
- Shared hardware such as printers and input devices.
- Shared data and information through the use of shared storage devices.
- Share software, which is achieve by running applications of remote computers. 2. Network types a. Local Area Network (LAN) Definition LAN (Local Area Network), also known as local area network, is used in a limited area with high transmission speed. Figure 1 Model of LAN
Devices on a LAN, typically personal computers and workstations, can share files and be accessed by each other over a single Internet connection. Devices using LAN can share resources with each other, typically sharing files, printer, etc. Advantage
- Inexpensive transmission media.
- It is used to high data transmission rates.
- It provides full proof of the security system against illegal access to data. b. Metropolitan Area Network (MAN) Definition A metropolitan area network (MAN), also known as urban network, is a computer network that connects computers within a metropolitan area, which could be a single large city, multiple cities and towns, or any given large area with multiple buildings. The MAN network model is often used mainly for organization and businesses with many branches and department connected to each other. Figure 2 MAN network connection MAN is made up of interconnected LANs. MANs typically combine the networks of multiple organizations, instead of being managed by a single organization. It is often used for businesses because this model provides many types of services such as connecting lines via voice, data, video, deploying applications easily.
Advantage
- WAN covers larger area. Hence business offices at longer distances can easily communicate.
- The software files are shared among all the users. Hence all will have access to latest files. This avoids use of previous versions by them.
- Like LAN, it allows sharing of resources and application among distributed workstations or users. 3. Protocol and standards Definition A network protocol is a set of established rules that dictate how to format, transmit and receive data so that computer network devices can communicate, regardless of the differences in their underlying infrastructures, designs or standards. They are the reason you can easily communicate with people around the world and therefore play a vital role in modern digital communication. To successfully send and receive information, devices on both sides of a communication exchange must accept and follow protocol conventions. Network protocols make it possible for devices to interact with each other due to predefined rules built into device’s software and hardware suffer. Neither a LAN nor a WAN could function as it does today without the use of network protocols. List common protocol 3.1. Internet Protocol: IP works similarly to a postal service. When users send and receive data from their devices, the data is concatenated into packets, like messages with two IP addresses: one for the sender and one for the recipient. After the packet leaves the sender, it goes to a port, like a post office, directing it in the appropriate direction. Packets continue to move through the ports until they reach their destination. IP is often paired with TCP to form TCP/IP, the overall set of internet protocols. Together, IP sends packets to their destination and TCP arranges the packets in the correct order, as IP sometimes sends packets out of order to ensure packets go the fastest way. 3.2. Transmission control protocol: TCP is the other half of TCP/IP and puts packets in order so that IP candeliverthem.specifically,TCPnumbersindividualpacketsbecauseIPcansendpacketstotheirdestination through different routes and make them out of order, so TCP modifies this before IP delivers packets .TCP also detects errors during sending - including the lack of any packets based on TCP's numbering system and asks IP to retransmit those packets before IP delivers the data to its destination. Through this process, the TCP/IP suite controls the communication on the internet. 3.3. File Transfer Protocol: FTP is a client-server protocol, with which a client requests a file and the server supplies it. FTP runs over TCP/IP, a suite of communications protocols, and requires a command channel and a data channel to communicate and exchange files, respectively. Clients request files through the command channel and receive access to download, edit and copy the file, among other actions,
through the data channel. FTP has grown less popular as most systems began to use HTTP for file sharing. However, FTP is a common network protocol for more private file sharing, such as in banking.
- Hypertext Transfer Protocol: Like FTP, HTTP is a file sharing protocol that runs over TCP/IP, although HTTP's superiority works across web browsers and is generally recognizable to most users. When a user visits a website domain and wants to access that domain, HTTP provides access. HTTP connects to the domain's server and requests the web page's HTML, which is the code that structures and displays the design of the page. 3.5. Domain name system: DNS is a database that includes a website's domain name, which people use to access the website, and its corresponding IP addresses, which devices use to locate the website. DNS translates the domain name into IP addresses, and these translations are included within the DNS. Server scan cache DNS data, which is required to access the websites. DNS also includes the DNS protocol, which is within the IP suite and details the specifications DNS uses to translate and communicate. DNS is important because it can quickly provide users with information, as well as access to remote hosts and resources across the internet. 3.6. Dynamic Host Configuration Protocol: DHCP assigns IP addresses to network endpoints so they can communicate with other network endpoints over IP. Whenever a device joins a network with a DHCP server for the first time, DHCP automatically assigns it a new IP address and continues to do so each time a device moves locations on the network. When a device connects to a network, a DHCP handshake takes place, where the device and DHCP server communicate. The device establishes a connection; the server receives it and provides available IP addresses; the device requests an IP address; and the server confirm it to complete the process. 4. International standard organizations Some international standards organizations: ▪ IEC - International Electrotechnical Commission ▪ IETF - Internet Engineering Task Force ▪ IEEE - Institute of Electric and Electronic Engineers ▪ IUPAC - International Union of Pure and Applied Chemistry ▪ W3C - World Wide Web Consortium ▪ ITU - The International Telecommunication Union ▪ ITU-R - ITU Radiocommunications Sector (CCIR) ▪ ITU-T - ITU Telecommunications Sector (CCITT) ▪ ISO - International Organization for Standardization ▪ OASIS - Organization for the Advancement of Structured Information Standards
Physical topology can be considered as a layout of the network media that shows the interconnections of the devices on the network. It specifies which geometric shape the linked devices form with each other. The physical topology does not give much comprehensive detail about the type of devices, the mechanism used for interacting with other devices in the network, and how data is transferred from one device to another. Therefore, it gives essential details of the network and network devices broadly, neglecting the higher-level details like device type, addressing schemes, connectivity, and so on. The factors that affect communication of devices on a network based on the physical topology selected are: ▪ Cost scalability ▪ Bandwidth capacity ▪ Ease of installation ▪ Ease of troubleshooting
3. Logical topology Unlike the physical topology, the logical topology emphasizes the manner in which data is transmitted between network nodes rather than the physical layout of the path the data follows. An important fact regarding these topologies is that both the physical and logical topologies are independent of a network, no matter what shape and size it may be. Such a logical topology is a signal path that traverses a physical topology. It handles: line discipline, error message, delivery frame according to order, optimal flow control. 4. The difference between physical topology and logical topology
- Logical topology is invisible in nature while physical topology can be customized.
- The physical topology is basically the physical layout of the network media. In contrast, logical topology refers to how, how data is transmitted throughout the network.
- The physical topology will not impede the transfer of data from one device to the other according to the logical topology. 5. The difference between physical topology and logical topology a. Mesh Topology Mesh topology is the kind of topology in which all the nodes are connected with all the other nodes via a network channel. Mesh topology is a point-to-point connection. It has n(n-1)/2 network channels to connect n nodes. Mesh topology has two techniques for transmission of data. In the routing technique, the nodes possess a routing logic, like the logic for the shortest distance to the destination node or the logic to avoid routes with broken connections. In the flooding technique, all the network nodes receive the same
data. This leaves us no need for routing logic. This technique makes the network robust but results in unwanted load on the network. Example: ALOHA, FabFi networking systems Figure 4 Mesh Topology Diagram Advantages of Mesh Topology
- Very robust
- It is easy to find faults
- Every connection has the ability to carry its particular data load
- Provides good privacy and security Disadvantages of Mesh Topology
- Bulk wiring is essential
- It is difficult to install and configure
- Cabling can often be very expensive b. Star Topology Star topology is a network topology in which each network component is physically connected to a central node such as a router, hub or switch. In a star topology, the central hub acts like a server and the connecting nodes act like clients.
Figure 6 Bus Topology Diagram Benefits of bus Topology
- Very cost effective
- Operation easy to understand
- Can be expansion by linking the cables
- The required cable length is the least compares to other topologies Drawback of bus Topology
- If the main cable goes down, the network is completely down
- Not as fast as ring topology
- Cable length is limited
- Network performance is reduced if there are many nodes and large network traffic Example of bus Topology: The 10Base-2 network
d. Ring Topology Figure 7 Ring Topology Diagram Ring topology is a type of network topology in which each device is connected to two other devices on either side via an RJ-45 cable or coaxial cable. This forms a circular ring of connected devices which gives it its name. Data is commonly transferred in one direction along the ring, known as a unidirectional ring. Benefits of ring Topology
- Has cheap installation and expansion
- The network is not affected by numerous nodes or heavy traffic, as only the nodes possessing tokens can transfer data
Drawback of tree Topology
- More expensive compare to other topologies
- If the root node collapses, the network will also collapse Example of tree topology: Corporate Network mainly based on the tree topology with helps maintain the management system f. Hybrid Topology A hybrid topology is a type of network topology that uses two or more differing network topologies. These topologies can include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology. The choice to use a hybrid topology over a standard topology depends on the needs of a business, school, or the users. The number of computers, their location, and desired network performance are all factors in the decision. Figure 9 Hybrid Topology Diagram Benefits of tree Topology
- It is scalable since the size can be made greater easily
- It is a flexible topology
- It is easy to troubleshoot and provides simple error-detecting techniques
Drawback of tree Topology
- It isn’t very easy to design
- It is expensive as it involves more than one topology Example of hybrid topology: Internet is an example of hybrid topology 6. Communication and bandwidth requirements A communication network is a pattern or form that is implemented in the organization to communicate information effectively. The communication network is the established system where the message may flow in one or too many directions in the organization based on requirements. a. The rules in the network BE INTERESTED IN WHO YOU’RE TALKING WITH Your aim is to build relationships by discovering some common ground and the easiest way to do this is by asking big, open-ended questions. Asking questions gets people talking – people love to talk about themselves. Don’t say too much, simply ask questions then pause. Use the silence to allow the other person to answer. For those of us who find it difficult to open up in social circles and meet new people, asking questions successfully deflects the attention away from you. That makes your job simple. Just keep asking probing questions, listen intently and hopefully pick up pieces of useful information. DON’T GET STUCK Where you position yourself in a room is key. The middle of the room is often the golden spot and should allow you to meet the maximum number of people. Everywhere you turn, you’ll be likely to strike up a new conversation. Avoid the corners of the room and standing against the wall, otherwise if you get locked in an unhelpful conversation and want to extract yourself you’ve limited your routes of escape. EXCHANGE CONTACTS Exchanging contact details, whether by swapping business cards or simply phone numbers, should be one of your key goals. Make sure you always have a pocket of cards and a pen. If you can, in a quiet moment soon after meeting someone, jot down something memorable about that person that will jog your memory when it comes to following up.
The more bandwidth a data connection has, the more data it can send and receive at the same time. Some devices require more bandwidth than others. Greater bandwidth is absolutely necessary if proper speeds have to be maintained across different devices. If you do not have enough bandwidth or available bandwidth when making calls, you might experience voice quality problems that could result in choppy voice, unexpected issues, and a poor user experience.
III. Discuss the operation principles of networking devices and server types (P3)
- Network devices Switches A network switch is a device that operates at the Data Link layer of the OSI model – layer 2. It receives packets sent by devices connected to its physical port and sends them back, but only through ports leading to the devices that packets are intended to reach. They can also operate at the network layer – layer 3 where routing takes place. Switches are a common component of networks based on ethernet, Fiber Channel, Asynchronous Transfer Mode (ATM), and InfiniBand, among others. In general, though, most switches today use ethernet.
- How does a network switch work? When a device is connected to a switch, the switch records its media access control (MAC) address, a code that is injected into the device's network interface card (NIC) attached to an ethernet cable. Attached to the switch. The switch uses the MAC address to determine where the attached device's outgoing packets are being sent from and where the packets are sent. A MAC address can be assigned to a physical device as opposed to a network layer (Layer 3) IP address, which can be dynamically assigned to a device and change time. When one device sends a packet to another, it goes into the switch, and the switch reads its header to determine what to do with it. It matches the destination address or addresses and sends the packet out through the appropriate ports to the destination device. To reduce the risk of collisions between network traffic going to and from a switch and a connected device at the same time, most switches provide duplex functionality where incoming and outgoing packets a device that has access to the full bandwidth of the connected switch.
- Router: a smart devices and store data on the network they are connected to. Routers allow packets to be transmitted to their destination by monitoring a sea of network devices that are interconnected with different network topologies.
- Other common networking devices (gateway) A gateway is a network node that forms a passage between two networks operating with different transmission protocols. The most common type of gateways, the network gateway operates at layer 3, i.e. network layer of the OSI (open systems interconnection) model. However, depending upon the functionality, a gateway can operate at any of the seven layers of OSI model. It acts as the entry – exit point for a network since all traffic that flows across the networks should pass through the gateway. Only the internal traffic between the nodes of a LAN does not pass through the gateway.
- Servers
- DHCP server: The DHCP server uses Dynamic Host Communication Protocol (DHCP) to configure the client computer's network settings. There are many enterprise companies who are still using DHCP for IPv4 on their routers/switches. This is typically done by the network administrator who needs to get a DHCP capability up and running quickly but does not have access to a DHCP server. Most routers/switches have the ability to provide the following DHCP server support
- DNS server: DNS servers, or “Domain Name Services” servers, are used to translate domain names to their respective IP addresses. The Domain Name System (DNS) Server is a server that is specifically used for matching website hostnames (like example.com) to their corresponding Internet Protocol or IP addresses. The DNS server contains a database of public IP addresses and their corresponding domain names.
- Database server: A database server often works in tandem with another type of server. This type of server exists only to store data in groups. Database servers are used to store and manage databases that are stored on the server and to provide data access for authorized users. This type of server keeps the data in a central location that can be regularly backed up. It also allows users and applications to centrally access the data across the network. A large number of the databases used in your organization can be kept on one server or a group of servers that are specifically configured to protect data and service client requests.
- Web Proxy Server. A web proxy server can run on one of many protocols, but they all have one thing in common. It provides a gateway between users and the internet. Therefore, it helps prevent cyber attackers from entering a private network. It is a server, referred to as an “intermediary” because it goes between end- users and the web pages they visit online. When a computer connects to the internet, it uses IP address.
