Fundamentals of Networking

Since seventies, computer networking is growing exponentially and has become an indispensable part of everyone’s life owing to its applications in varied commercial sectors including private and government like schools, banks, hospitals, military organisations, and even homes. However, it is extremely confusing for a beginner due to lack of consistency in networking standards and its terminology. Hence, to excel in networking, it is imperative to dig deeper and understand the five key aspects as such:

1.       Internet applications and network programming.

2.       Data communications.

3.       Packet Switching and networking technologies.

4.       Internet working with TCP/IP.

5.       Additional networking concepts and technologies.

** ISP: Internet Service Provider.

Understanding Network Programming/ Networking:

Internet offers distinct applications for the convenience of end users offering well defined protocols. Along with this, it also offers various network services like naming, configuring, filing and printing  servers. All internet applications work on single transport layer that provides TCP and UDP and Network layer providing IP and port numbers ( System, User and Dynamic) to create a possible communication channel between them. There are two main paradigms for writing Internet applications that is client server and Peer-to-Peer(P2P).

Network programming involves writing computer programs enabling communication between different devices connected across a computer network whether its connection oriented or connection-less. Traditionally network planning includes seven different layers of OSI/ISO model as below:

OSI Model

** TCP: Transmission Control Protocol: Connection Oriented communication that allows reliable communication between two applications.

**UDP: User Data-gram Protocol: Connection-less Communication that allows transfer of packet data between two applications.

**IP: Internet Protocol: Label or address assigned to each device connected with the computer.

**OSI/ISO: Open Systems Interconnection: Model showing the communication of applications over a network.

Network Hardware Components:

For planning, troubleshooting and maintenance of networks some devices are generally used like Servers, Routers, Repeaters, Hubs, Switches, Bridges, Gateways and many more.

1. Servers: Performs network functions for the computers and have several categories:

•  File and Print Servers
• Application servers
• E-Mail servers
• Networking servers
• Internet servers 
• Remote Access servers

2. Routers: A device that allows transfer of data in the form of packets from one network to another. Basically, it is used to provide broadband internet connection either to a PC or LAN in an organisation. They also contain RJ 45 Ports to connect other network devices using network cables.

3. Repeaters: Repeaters acts as a signal boosters that re-generates signals and allows transmission of them at a longer distance.

4. Hubs: Consists of several Input and Output ports and can splits the same network signals into all connected computers. It also acts as a multi port repeater.

5. Switches: It is an advanced version of a hub and uses physical address to send the signal only to the destination port instead of broadcasting it.

6. Bridges: It connects two separate Ethernet network (following same protocol) together and establish a connection between them by forwarding packets from one port to the destination port.

7.Gateways: It acts as a gate that allows entrance of a signal in a network  and can connect entirely different networks (following different protocols) together to allow transfer of signals.

Network Hardware Devices

Network Cables:

Out of the various network cables available in the market, the most common used cable for LAN's is Category 5 (Cat-5) or Category 6 (Cat-6) which is a twisted pair cable and allows the network signal to travel through eight wires in total (four twisted pairs), and follows different arrangements and color coding to transfer different signals through Ethernet cables.

CAT5 Cable

1. Standard or Straight: Here both the ends of the cable follows same colour coding or wiring pattern as below:

RJ45 Pin#	Wire Color	10/100 Base-T Use
1	White/Orange	Transmit +
2	Orange	Transmit -
3	White/Green	Receive +
4	Blue	Unused
5	White/Blue	Unused
6	Green	Receive -
7	White/Brown	Unused
8	Brown	Unused

2. Crossover:  Here the arrangement of both the ends are different from each other as below:

RJ45Pin#(END1)	Wire Color(END1)	RJ45 Pin#(END2)	Wire Color(END2)
1	White/Orange	1	White/Green
2	Orange	2	Green
3	White/Green	3	White/Orange
4	Blue	4	White/Brown
5	White/Blue	5	Brown
6	Green	6	Orange
7	White/Brown	7	Blue
8	Brown	8	White/Blue

 ** LAN: Local Area Network: A computer network that allows communication between computers within a limited area.
**RJ45: Registered Jack 45: Standardized networking interface used for Ethernet cabling.

Understanding Cable Topologies:

Network Topologies or Network Architecture refers to the shape of the network. To clarify, it means the logical arrangement in which all the points (nodes) of a network are connected together via network wires. Network follows various topologies like Point to Point, Bus, Star, Ring, Tree, Mesh, Hybrid, their overview is as below:

S. No.	Topology	Definition	Advantages	Disadvantages
1	Point to point	Direct link between two computers	Faster and Reliable	Used only for small areas where computers are in close proximity.
2	Bus	Uses one main cable to connect all the computers or nodes	Easy to connect and cost effective	If one cable breaks the entire network can broke down. Hence, it is difficult to troubleshoot.
3	Ring	Devices are connected in a circular form indicating a ring.	Easy to install and configure and detecting faults within a network.	It has unidirectional traffic and break in a single ring can halt the entire network.
4	Star	Each computer is connected with a hub at the center using point to point connection.	Problem with one node does not affect other nodes.	More expensive, because it requires more cables for connecting devices.
5	Tree	Elements are connected in an arrangement similar to branches of the tree.	Expansion of nodes is easy, and the network can be easily maintained, managed and diagnosed in case of any error.	If central hub is failed, then the whole network will stop working. Maintenance is also difficult because it is heavily cabled and hence, costly as well.
6	Mesh	All nodes cooperate with each other to distribute data.	Traffic can be easily managed, and failure of a device does not affect data or network flow.	Cost, building and maintenance of a network is on high side.
7	Hybrid	Includes mixing of two or more different network topologies.	Reliable having better fault tolerance. Offers flexibility, hence, most effective.	Extremely complex and expensive architecture, therefore, needs expert designers.

Network Topology

Networking Protocols:

A network protocol is a set of rules followed to establish a communication network and completing desired network transactions. Some commonly used network protocols are TCP/IP and UDP, DNS, DHCP, HTTP, FTP, SMTP, VoIP and so on.

1. TCP/IP and UDP:  TCP/IP is basically two different protocols but generally used together in concert with each other. Here, the IP (Internet Protocol), not only defines the way to address network data from source to destination but also tells the correct sequence in which the data is re-assembled at the other end. It operates at the network layer in OSI model. Whereas, the TCP (Transmission control protocol) operates at Transport Layer. It mainly manages connections between computers.

However, the UDP (User Datagram Protocol) has almost similar roles as TCP but unlike TCP, it re-sends any un-received packet back and is faster and reliable for insignificant network communications.

2. DNS: Domain Name System: It is a naming system introduced for humans to access online information eliminating the need to remember complex IP addresses. Here, some domain names are assigned to various IP addresses to make it convenient for humans to access them.

3. DHCP: Dynamic Host Configuration Protocol: It basically deals with network management where the server assigns an IP address, default gateways and other network parameters to develop a communication between different networks.

4. HTTP: Hypertext Transfer Protocol: Protocol used by World Wide Web (WWW) to access hypertext documents including hyper text links can easily be accessible by the user through various web browsers like Google chrome, Mozilla Firefox, Microsoft Internet Explorer and so on.

5. FTP: File Transfer Protocol: It is an application layer protocol primarily used for sending and receiving files between a client and a server where transfers are generally text-based and password protected.

6. SMTP: Simple Mail Transfer Protocol: It is an application layer protocol used for sending and receiving E-mail messages between servers and is decoded at the receiver end by using one of POP (Post Office Protocol) or IMAP (Internet Message Access Protocol).

7. VoIP: Voice Over IP: It is a process of transmitting voice calls or messages over IP networks and allows us to make free or very less priced telephone calls over the internet.

Remote Network Access:

Allows users to access the system or a network through a network connection even if the person is not physically present at the site. To establish remote access connections different technologies are used as such:

1. Remote Node: A process in which a terminal or a computer system located far away from the main network can access LAN connection via an Internet or dial-up connection.

2. Remote Control: A process in which a remote user can take control of another workstation directly connected with LAN via some software installed on both the PCs. This also uses a dial-up line or an Internet connection.

Remote Control Session

3.VPN: Virtual Private Networks: A link created between the remote user (Connected to ISP) and the company's LAN via Internet over a public network. It uses encrypted layered tunneling protocol that makes it a secure private network and often requires authentications to gain its access.

Typical VPN Connection

Network Security:

It consists of set of rules, regulations and policies adopted to protect the integrity and prevent unauthorized access of a computer network peripherals either by hardware or software. Basically threats may be Internal, external or by viruses and other malicious software.

1.Internal Security: Refers to securing the network from internal threats like accessing unauthorized information by impersonating other users or deliberately introducing viruses to the network. Sometimes the users even sniff packets on the network to discover login in credentials of the company.

2. External Threats: Refers to securing network from external threats like Front-Door Threats, Back door Threats and Denial of Service (DoS).

    **Front-Door Threats: It arises when an outsider cracks the password and access the network.

   **Back-Door Threats: It arises when software or hardware bugs allow attacker to login the administrative account.

    **Denial of service(DoS): It arises when an intruder crashes servers or create useless traffic to barren the access and denies service to the network.

3. Viruses and other Malicious Software: Unfortunately, some software and programs are specifically used or created with ill intention like:

    **Viruses: It is a program that infects other files by creating a copy of itself.

    **Worms: It is a program that propagates by sending copies of itself to other computers and there after again to others without the knowledge of the user.

    **Trojan horses: It is a program that misleads the user by hiding its true intention and doing malicious activities in the background.

    **Logic Bombs: It is a program that is intentionally inserted into a software to take its advantage (Often with ill intention) when certain conditions are met.

Network Designing:

Network designing is not an exact science but an iterative process that aims to ensure that the user's and project's requirements are fulfilled. It acts as a backbone of any IT business because it creates a network and connects all the network devices together allowing information access through out the industry. Before implementing any network design, it is planned to ensure its efficiency.

Any network design should show:

1. A clear map of the network.
2. Layout or wiring diagram of the cables.
3. The location, quantity and types of devices to be used.
4. Following a particular structure of IP Address.
5. Deciding network security architecture and processes.

To ensure the designed network is best following things are taken into account:

1. Actual design phase should be done diligently.
2. Always plan while keeping future in mind.
3. Security should be embedded in the design.
4. Network should be properly monitored.
5. Network designing never finishes.

Project Planning

Project Planning for CCTV Installation:

Before initiating any project, several attributes are taken into consideration. Therefore, I did some online research to understand the flowchart and the steps followed in the execution of projects by the organisations related to CCTV (IP) Security. Below is the hierarchy of the steps involved followed by a flow chart for lay man understanding:

Steps of Project Planning	Description
Understanding the requirement	As every individual have their own requirement and purposes behind installing cameras, the first stage is to understand it by communicating with the end users and then creating a blue print of how things will be implemented and the project will be executed.
Assigning a visit (If required)	A supervisor or a technician is then sent to the project site where he, based upon his experience can suggests the critical points where chances of trespassing is maximum and also suggest the locations for the cameras to be installed, to provide maximum coverage and hence, barring any possible theft.
Designing Solution	After site visit the supervisor then designs all the possible solutions and choose the best among them by cross checking if the requirement of the customer is being fulfilled. And finally, create a quotation for the end user by briefing them about the estimated cost for the whole project
Negotiations	The customer then checks his budget and do certain negotiations with the vendor to bring the cost of the project into his reach and finally give green signal to execute the project.
Execution	In this phase, the vendor allocate a team of technicians for project realisation and then send them over to the site with all the products specified in the solution and installation and commission of the cameras gets started, while complying with the guidelines given by both supervisor and client.
Site handover	Finally, brief overview of all the installed system is given to the customer. Along with this, he is explained how to check the views of the cameras on local or remote network via different software or mobile applications. He is also asked to setup a password of the whole system and advice him not to share it with any outsider by assuring 100% safety of the consumer.

Flow Chart

Personal Evaluation (Achieving Goal)

Personal Evaluation (Acheiving Goal) 

Aims and Objectives:

By this project my core aim is to provide sense of security that everyone strives of in this atrocity as it allows continuous monitoring on or before any particular happening. For achieving my goal, I did some personal evaluation to check if I have certain skills necessary for the execution of the whole project and I discover some striking facts both positive and negative about myself by self-evaluation as such:

Positives	Contribution in project Execution
Working efficiently with a computer	Computer literacy is eminent as IP cameras can only be configured by connecting them by CAT6 with the Modem.
Analytical Thinking and diagnosing faults	It is a critical component that allows person to solve problems quickly and effectively, as here I have to deal with different networks to ensure their connectivity, this skill can be a boon for me.
Eagerness to learn about latest technologies	Due to the advancement in technology, new changes are made regularly, hence, this quality will be challenging and encourage me to broaden my knowledge every day.
Following step by step approach in a process	For successful execution of any project, Step by step approach is essential, because if any step is missed in between the whole process can come to halt.
Time Management skills	Creating a timeline and following it throughout the project can be advantageous not only to the whole team or company but also to the end user.

Areas requiring improvement	My Contribution
Knowledge of Networking	As a complete beginner to the networking equipments like routers, servers, switches and modems; I am doing extensive study both online and offline to learn the different commands for configuring them with the existing set up. The book I am using for this is (Home Wireless Networking in a snap, by Joe Habraken)
Computer Systems and Networks	To understand the basic taxonomy of intrusion detection systems, basic knowledge of computer systems and networks is required. Hence, I am following the scholarly articles and journals published at MyBeckett library resources.
Troubleshooting	Sometimes system does not work as expected even after following the ideal workflow, so, I started learning the ways to monitor and troubleshoot network problems from the website. (https://www.dnsstuff.com/network-troubleshooting-steps)
Communication Skills (Written/ Verbal)	I struggle and sometimes get short of words, while creatively communicating my objectives. Therefore, I am making communication with others my priority and engaging in conversation with native speakers. Side by side I am also developing listening and writing skills by brushing up the basic principles of writing like grammar and spellings.

SWOT Analysis

SWOT is an abbreviation of Strengths, Weaknesses, Opportunities and Threats. Here, Strengths and Weaknesses are internal and related to projects within the company; however, Opportunities and Threats are external things going outside. Before initiating my project, I will specify everything required to develop the project. Below I am sharing the layout of the same:

SWOT Analysis
S	W	O	T
Strengths	Weaknesses	Opportunities	Threats
Protection of assets and valuables	Expensive	Wider area and market growth	Constant Change in Technology
Deterioration in crime rates	Vulnerable and can be hacked	Employment and job opportunities	Highly competitive market
Remote Monitoring	Intrusion of privacy	Detection of potential crime	Systems can be misused for theft
Alerts during any intrusion	Do not prevent crime	Flexibility for working individuals
Sense of security (Phychological)	Monitor a limited area
Collect Evidence and keep records

Introduction to Home Security Systems

As Home burglaries and property trespassing has become a common trend, security, whether it’s of life or property has become a necessity for every individual. However, by the introduction of home security systems, safety of individuals can be ensured to a large extent. Hence, the project I picked for my negotiated skills development is the same.

Although, home security is a very vast field and includes different types as such:

1.       Closed Circuit Television (CCTV)

2.       Intrusion Alarm System.

3.       Fire Alarm System

4.       Video Door Phones

5.       Biometric sensors and readers and so on.

In this blog, I will focus deeply on the first segment that is CCTV. This also has various variants like Analog and HD Cameras, IP Cameras, Mobile surveillance and many more. My primary focus will be on Internet Protocol (IP) based cameras. For executing this, I had choosen devices of Make: Hikvision.