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HND in Computing Programme

Networking

Thamindu Sharitha Galappaththi

MG

Table of Content

1 Introduction

• With the advancement of technology everything has become interconnected. People use these interactions to make their lives easier. It is important to maintain a relationship in the home environment or in the business environment. The network uses this connection to activate. Networking plays an important role in the business environment. Tends to be more efficient and convenient with networking.
• In this report, I have designed and implemented a network system in accordance with the server specifications. I first identified the client's needs and then added devices such as routers, switches and servers to meet those needs. A cost analysis was performed for these network devices. In selecting network devices, a cost analysis was performed, and a network security analysis and QoS were considered to obtain a better alternative for these devices. DHCP server, file server, DNS server, web-email server were added to make the network location more efficient.
• A plan was created before activating the network system. This design was successfully done using a Cisco packet tracer. Network activation was performed using the Windows Server 2012 R2 network operating system. Through this trip I was able to learn the basics of network design and implementation and how to successfully design and execute a network system. This experience has provided an insight into the business infrastructure of the network system and how the entire business is interconnected using the network system.

1.2 Network Principles and Protocols

An article that is published by the Cabinet Office outlining network principles, explains how the underlining networking infrastructures should be transparent and resilient as well as ever-present for all its users. This publication defines several basic networking requirements that should be taken into consideration when designing a network, these include the following:

• Bandwidth
• Availability
• Resilience
• Cost

1.2.3 Network Types

01 Peer-Based Network

In peer-to-peer (P2P) networking, a group of computers are linked together with equal permissions and responsibilities for processing data. Unlike traditional client-server networking, no devices in a P2P network are designated solely to serve or to receive data. Each connected machine has the same rights as its “peers”, and can be used for the same purposes. Advantages

• Easy and simple to set up only requiring a hub or a switch to connect all computers together.
• You can access any file on the computer if it is set to a shared folder.
• If one computer fails to work all the other computers connected to it continue to work. Disadvantages
• Security is not good other than setting passwords for files that you don't want people to access.
• If the connections are not connected to the computers properly then there can be problems accessing certain files.
• It does not run efficient if you have many computers, it is best to used two to eight computers.

• No graceful degradation of system – abrupt failure of the entire system
• Less possibility of data backup. If the server node fails and there is no backup, you lose the data straight away

04 Clustered Network

A cluster network is two or more computing devices working together for a common computing purpose. These networks take advantage of the parallel processing power of the computing devices. In addition to the increased processing power, shared computing resources in a cluster network also can provide scalability, high availability, and failover capabilities should one computing device have a problem. Advantages

• PERFORMANCE Throughput and response time are improved by using a group of machines at the same time.
• AVAILABILITY If one node fails, the workload is redistributed among the other nodes for uninterrupted operation.
• INCREMENTAL GROWTH Performance and availability can be enhanced by adding more nodes to the cluster.
• SCALING Theoretically, there is no limit on the number of machines that can belong to the cluster.
• PRICE AND PERFORMANCE The individual nodes of a cluster typically offer very good performance for their price. Because clustering does not involve the addition of expensive high-performance processors, buses, or cooling systems, the cluster retains the price/performance advantage of its individual members. Disadvantages
• Cost is high
• Monitoring and maintenance is hard

05 Cloud Network

Cloud networking refers to hosting or using some or all network resources and services—virtual routers, bandwidth, virtual firewalls, or network management software—from the cloud, whether public, private, or hybrid. The network can be either cloud-enabled or entirely cloud-based.

Advantages

• Storage and Scalability
• Backup and Recovery
• Flexibility
• Cost Efficiency
• IT Innovations Disadvantages
• Less Control and Reliability
• Less Security and Compliance
• Less Compatibility
• Less Cost Unpredictable
• Less Contracts and Lock in

06 Virtualized

Network Virtualization (NV) refers to abstracting network resources that were traditionally delivered in hardware to software. NV can combine multiple physical networks to one virtual, software-based network, or it can divide one physical network into separate, independent virtual networks. Network virtualization software allows network administrators to move virtual machines across different domains without reconfiguring the network. The software creates a network overlay that can run separate virtual network layers on top of the same physical network fabric. Advantages

• Uses Hardware Efficiently
• Available Always
• Recovery is Easy
• Quick and Easy Setup
• Cloud Migration is Easier Disadvantages
• High Initial Investment
• Data Can be at Risk
• Quick Scalability is a Challenge
• Performance Witnesses a Dip

• Has better range compared to infrared communication. PAN disadvantages
• Bluetooth can lose connectivity under certain conditions.
• Uses low bandwidth compared to other wireless specifications (WIFI).
• Only allows short range communications between other devices.
• Can be exploited easily compared to other wireless standards (WIFI).

03 Metropolitan Area Network

Metropolitan area networks are like local area networks however, Man’s typically span an entire city area and interconnect multiple LAN’s together. MAN is larger than a LAN but smaller than a WAN and provide fast communication making them efficient. MAN’s use carriers that support fiber optic cabling media. MAN Benefits

• Better security compared to WAN’s.
• Have higher bandwidth compared to WAN technology.
• Are less expensive to setup compared to WAN’s MAN Constraints
• More complex to manage compared to LAN’s
• Are not recommended for copper media.
• Security can be more easily exploited compared to LAN’s

04 Wide Area Network

The wide area network is generally associated with two or more local area networks that are separated geographically, the wide area is the part of the network that is represented by the internet service provider to ensure that the LAN is able to connect to the Internet. WAN Benefits

• Allow the sharing of resources and applications between geographical locations.
• File data can be quickly shared between users within different locations.
• High bandwidth data transfer rates. WAN Constraints
• Security appliances such as firewalls are required to protect against intrusion.

• Wide area connection issue sometimes make circuit unavailable.
• Initial WAN setup costs can sometimes be high especially for new sites

3. Network Layer - The network layer has two main functions. One is breaking up segments into network packets, and reassembling the packets on the receiving end. The other is routing packets by discovering the best path across a physical network. The network layer uses network addresses (typically Internet Protocol addresses) to route packets to a destination node. 4. Transport Layer - The transport layer takes data transferred in the session layer and breaks it into “segments” on the transmitting end. It is responsible for reassembling the segments on the receiving end, turning it back into data that can be used by the session layer. The transport layer carries out flow control, sending data at a rate that matches the connection speed of the receiving device, and error control, checking if data was received incorrectly and if not, requesting it again. 5. Session Layer - The session layer creates communication channels, called sessions, between devices. It is responsible for opening sessions, ensuring they remain open and functional while data is being transferred, and closing them when communication ends. The session layer can also set checkpoints during a data transfer—if the session is interrupted, devices can resume data transfer from the last checkpoint. 6. Presentation Layer - The presentation layer prepares data for the application layer. It defines how two devices should encode, encrypt, and compress data so it is received correctly on the other end. The presentation layer takes any data transmitted by the application layer and prepares it for transmission over the session layer. 7. Application Layer - The application layer is used by end-user software such as web browsers and email clients. It provides protocols that allow software to send and receive information and present meaningful data to users. A few examples of application layer protocols are the Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), and Domain Name System (DNS).

The advantages of the OSI model are

• It is a generic model and acts as a guidance tool to develop any network model.
• It is a layered model. Changes are one layer do not affect other layers, provided that the interfaces between the layers do not change drastically.
• It distinctly separates services, interfaces, and protocols. Hence, it is flexible in nature. Protocols in each layer can be replaced very conveniently depending upon the nature of the network.
• It supports both connection-oriented services and connectionless services.

The disadvantages of the OSI model are

• It is purely a theoretical model that does not consider the availability of appropriate technology. This restricts its practical implementation.
• The launching timing of this model was inappropriate. When OSI appeared, the TCP/IP protocols were already implemented. So, the companies were initially reluctant to use it.
• The OSI model is very complex. The initial implementation was cumbersome, slow and costly.
• Though there are many layers, some of the layers like the session layer and presentation layer have very little functionality when practically deployed.
• There is a duplication of services in various layers. Services like addressing, flow control and error control are offered by multiple layers.
• The standards of OSI model are theoretical and do not offer adequate solutions for practical network implementation.
• After being launched, the OSI model did not meet the practical needs as well as the TCP/IP model.
• TCP/IP model was very much preferred by the academia. It was believed that OSI was a product of the European communities and the US government, who were trying to force an inferior model to researchers and programmers.

03 Internet Layer An internet layer is a second layer of TCP/IP lays of the TCP/IP model. It is also known as a network layer. The main work of this layer is to send the packets from any network, and any computer still they reach the destination irrespective of the route they take. The Internet layer offers the functional and procedural method for transferring variable length data sequences from one node to another with the help of various networks.

• Message delivery at the network layer does not give any guaranteed to be reliable network layer protocol. Layer-management protocols that belong to the network layer are: I. Routing protocols II. Multicast group management III. Network-layer address assignment. The Network Interface Layer
• Network Interface Layer is this layer of the four-layer TCP/IP model. This layer is also called a network access layer. It helps you to defines details of how data should be sent using the network.
• It also includes how bits should optically be signaled by hardware devices which directly interfaces with a network medium, like coaxial, optical, coaxial, fiber, or twisted-pair cables.
• A network layer is a combination of the data line and defined in the article of OSI reference model. This layer defines how the data should be sent physically through the network. This layer is responsible for the transmission of the data between two devices on the same network.

Advantages of TCP/IP Modes

The advantages of TCP/IP protocol suite are

• It is an industry–standard model that can be effectively deployed in practical networking problems.
• It is interoperable, i.e., it allows cross-platform communications among heterogeneous networks.
• It is an open protocol suite. It is not owned by any particular institute and so can be used by any individual or organization.

• It is a scalable, client-server architecture. This allows networks to be added without disrupting the current services.
• It assigns an IP address to each computer on the network, thus making each device to be identifiable over the network. It assigns each site a domain name. It provides name and address resolution services.

The disadvantages of the TCP/IP model are

• It is not generic in nature. So, it fails to represent any protocol stack other than the TCP/IP suite. For example, it cannot describe the Bluetooth connection.
• It does not clearly separate the concepts of services, interfaces, and protocols. So, it is not suitable to describe new technologies in new networks.
• It does not distinguish between the data link and the physical layers, which has very different functionalities. The data link layer should concern with the transmission of frames. On the other hand, the physical layer should lay down the physical characteristics of transmission. A proper model should segregate the two layers.
• It was originally designed and implemented for wide area networks. It is not optimized for small networks like LAN.

including computers, routers and servers to ensure each one, and the network as a whole, perform optimally. Network management protocols ▪ Connection: These protocols establish and maintain stable connections between different devices on the same network. ▪ Link aggregation : Link aggregation protocols allow you to combine multiple network connections into one link between two devices. This works to increase the strength of the connection and helps sustain the connection should one of the links fail. ▪ Troubleshooting: Troubleshooting protocols allow network administrators to identify errors affecting the network, evaluate the quality of the network connection, and determine how administrators can fix any issues. ▪. Below are some more protocols

• Transmission Control Protocol (TCP ): TCP is a popular communication protocol which is used for communicating over a network. It divides any message into series of packets that are sent from source to destination and there it gets reassembled at the destination.
• Internet Protocol (IP): IP is designed explicitly as addressing protocol. It is mostly used with TCP. The IP addresses in packets help in routing them through different nodes in a network until it reaches the destination system. TCP/IP is the most popular protocol connecting the networks.
• User Datagram Protocol (UDP): UDP is a substitute communication protocol to Transmission Control Protocol implemented primarily for creating loss-tolerating and low-latency linking between different applications.
• Post office Protocol (POP): POP3 is designed for receiving incoming E-mails.
• Simple mail transport Protocol (SMTP): SMTP is designed to send and distribute outgoing E-Mail.
• File Transfer Protocol (FTP): FTP allows users to transfer files from one machine to another. Types of files may include program files, multimedia files, text files, and documents, etc.
• Hyper Text Transfer Protocol (HTTP): HTTP is designed for transferring a hypertext among two or more systems. HTML tags are used for creating links. These links may be in any form like text or images. HTTP is designed on Client-server principles which allow a client system for establishing a connection with the server machine for making a

request. The server acknowledges the request initiated by the client and responds accordingly.

• Hyper Text Transfer Protocol Secure (HTTPS): HTTPS is abbreviated as Hyper Text Transfer Protocol Secure is a standard protocol to secure the communication among two computers one using the browser and other fetching data from web server. HTTP is used for transferring data between the client browser (request) and the web server in the hypertext format, same in case of HTTPS except that the transferring of data is done in an encrypted format. So, it can be said that https thwart hackers from interpretation or modification of data throughout the transfer of packets.
• Telnet : Telnet is a set of rules designed for connecting one system with another. The connecting process here is termed as remote login. The system which requests for connection is the local computer, and the system which accepts the connection is the remote computer.
• Gopher : Gopher is a collection of rules implemented for searching, retrieving as well as displaying documents from isolated sites. Gopher also works on the client/server principle.

1.4 Types 0f Network Devices