The History Of Networking Components

Published Date: 02 Nov 2017

Introduction

In this report, I will demonstrate understanding of local area technologies, and how they relate to St John’s College. I will include networking concepts, networking components, connection technologies, Ethernet access control, networking topologies, networking models, IP addressing and schema.

Networking Concepts

A LAN is a type of computer network that is designed to interconnect small areas of computers, such as home, school, or small businesses. It is used to transfer data at very fast rates between a small area network, and is very secure because of its Peer to Peer connection.

The advantages the user would get from using a Local Area Network is that there is a fast transfer rate between the devices, it has a high security as it doesn’t have to have access to an external network (but it can). Other advantages are that devices on the network can share peripheral devices such as printers, and that they can save work on a central server, and can access that work from any device on that particular network.

The disadvantages are that special security would be needed to stop users from accessing programs and data that they should not have access to. Another is that if the central server develops a serious fault, all the users will be affected, instead of just the one user in the case of a stand-alone device.

The benefits St Johns would get from a LAN network is fast file/data transferring between users, whether it be a teacher sending it to a student, a student to another student, or teacher to teacher. It also allows the host, whether it be the teacher or another staff member, to control the users access to external networks and internal usage, by shutting them out of the internet, or cutting them off from certain programs.

A Peer to Peer (P2P) computer network is a computer network in which each computer in the network can act as a client or server for the other computers in the network, allowing shared access to various resources without the need of a central server.

A Client Server is a computer network in which there is one centralized, more powerful computer to act as the server. It is a hub for many less powerful personal computers or workstations to connect to. These lesser computers, also known as clients, run programs and access data that are stored on the server.

The advantages of a P2P network are:

- Easy to add new devices to the network

- All the contents are shared by all the users

- More reliable than a Client server because it is not all based around a single hub

- No need for a single Administrator, every user is the administrator of his/her own computer

The disadvantages of a P2P network are:

- Because everyone is the administrator of their own computer, not one person can control the accessibility of the whole network

- Security isn’t very reliable; it is easy to send malicious software to other users on the P2P network

- Data recovery/backup is difficult using P2P.

The advantages of a Client Server are:

- There is a central hub which means that all of the files are saved in the same place for easy access

- Because all of the data is stored on one server, backups and recovering files is easy

- Easily accessed from various platforms, including remotely.

The disadvantages of a Client Server are:

- Too many requests sent to the hub can congest the server, this can cause and overload which could lead to the breaking down of the server

- If the central server fails, the whole server goes down

- Very expensive compared to the P2P network.

- Need someone such as an IT specialist monitoring the server at all times

Networking Components

Network Bridge:

- Network Bridging describes the action taken by network equipment to allow two or more communication networks, or two or more network segments to create an aggregate network.

Repeater:

- A repeater is an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction so that the signal can cover long distances.

Network Card:

Network Cables:

- Network cables carry information between computers in a wired LAN.

Network Hub:

- A network hub acts as a signal data transmission to computers in a LAN. When data from one computer reaches the hub it is sent to every computer in the network.

Network Switches:

- An alternative to the network hub is the network switch. Switches they assigns each computer in the network a MAC address. This allows LANs using a network switch to route information to individual computers.

Router:

- Routers connect all computers to one network rather than connecting computers in a single network. They connect the computers to the internet, however, they can be used to connect any networks.

Connection Technologies

Wired Connection is a connection that implements logic using only passive components such as diodes and resistors. A wired connection can create an AND or an OR gate. The limitations are the inability to create a NOT gate and the lack of level restoration.

Optical Connection is a connection created from fibre optic cables. An optic fibre is a flexible, transparent fibre made of silica or plastic, slightly thicker than human hair. Fibre optic cables are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths than other forms of communication. Fibers are used instead of metal wires because signals travel along with them with less loss and are also immune to electromagnetic interference.

Wireless Connection refers to any type of computer network that is not connected by cables of any type. It is a method by which homes, telecommunications networks and business installations avoid the costly process of introducing cables into a building, or as a connection between various equipment locations.

The advantages of a wired connection are that it is cheap, yet has the highest security rate out of all of the connection types. It is also more reliable then both wireless and the optical connection. The disadvantages of a wired connection are that it isn’t as organized or as clean as the other connections. If they are setup to run long distances, most times, new cable will just be added without removing the old one. After a while, the connection gets messy and confusing.

The advantages of an optical connection are that they have a faster bandwidth then both wireless and common cabling. The disadvantages are that it is a lot more expensive than both wireless and common cabling.

The advantages of a wireless connection are that it is cheap and users can access the internet without having to be physically connected to the modem/router. The disadvantages are that it is the slowest out of all of the connection types.

Bandwidth is the data transfer rate of a network. It shows how much data can be sent over a connection in a certain amount of time

Simplex: the communication takes place in one direction. The receiver receives the signal from the transmitting device.

Half-duplex: the communication is used in both ways, but one direction at a time.

Full-duplex: the communication channel can be used both ways at the same time

Ethernet Access Control

Modern networks use ethernet as their means of sending packets to external networks. Devices communicating over Ethernet divide a stream of data into shorter pieces called frames. Each frame contains source and destination addresses and error-checking data so that damaged data can be found and re-sent.

The Ethernet access control method used in ethernet architecture today is a firewall. The firewall restricts what network traffic can get into the internal network, or out of it, by analyzing the data packets and then determines whether it is safe to go past the firewall and into the internal network. It will stop things such as viruses and other malicious software from getting into the internal network and stop them from causing damage to the computer. Another thing restricting people getting malicious software uploaded to their network is a password set to your connection (eg WEP key), so that people cannot connect without that password. This restricts people from bypassing your firewall and uploading malicious software straight to your internal network.

The Ethernet access control method used in a Local Area Network is dependent on where the LAN is set up. In a larger facility such as a workplace or school, it will have something such as a NAC (Network Access Control), which is a host computer on the internal network which controls what the other computers can access, and can view what they’re doing and can also take control if needed. In a school network, this is used to stop students from going on inappropriate sites during school time. The host can also cut off the computers access to external networks by redirecting them to a page of the hosts choice.

Networking Topologies:

There are 3 different types of network topologies, STAR, BUS, and RING. In a STAR network, all the components of the network are connected to a central hub. In a BUS network, all of the the components are connected through the same cable. In a RING network, all of the components connect in a continuous pathway which forms a circle.

The advantages of a STAR network are :

- It is easy to connect new devices

- It is easy to find and troubleshoot a fault

- It is easy to monitor the network

The disadvantages of a STAR network are :

Star Network

- If the central device goes down, so does the whole network

Bus Network

- It is expensive to set up because of the cost of the router/switch

- The performance of the devices on the central device

The advantages of a BUS network are :

- Easy to set up and extend

Ring Network

- Cheap to set up

The disadvantages of a BUS network are :

- There is no limit to the number of devices that can be connected

- It is hard to find and troubleshoot a fault

- Security is low

- The more devices that connect, the speed of the bus is reduced

The advantages of a RING network are :

- Very organized

- No need for a server to control the connectivity

- Each computer has equal abilities to access resources

- The performance is not affected by additional component.

The disadvantages of a RING network are:

- Each packet must pass through all the devices between where it came from and where it is going

- If one workstation fails, the entire network will be affected

- The network is highly dependent on the wire which connects different components

St John’s College uses an extended star network such as the one below:

Networking Models:

TCP/IP defines how electronic devices should be connected to the internet, and how it should be transmitted. TCP and IP work together to take care of the communication between application software (TCP), and to make sure the packeted data is sent to the correct location (IP).

NAT (Network Address Translation) is the process where a network device, usually firewall assigns a public address to a computer (or group of computers) inside a private network. The main use of NAT is to limit the number of public IP addresses an organization or company must use, for security purposes. Routers inside a private network can route traffic between private addresses with no trouble, however, to access resources outside the network, like the internet, these computers have to have a public address in order for responses to their requests to return to them. A workstation inside a network makes a request to a computer on the internet. Routers within the network recognize that the request is not for a resource inside the network, so they send it to the firewall. The firewall sees the request from the computer with the internal IP, It then makes the same request to the internet using its own public address, and returns the response from the internet resource to the computer inside the private network. From the perspective of the resource on the internet, it is sending information to the address of the firewall. From the perspective of the workstation, it appears the communication is directly with the site on the internet. When NAT is used in this way, all users inside the private network access the internet have the same public IP address when they use the internet, just like a firewall.

A firewall is used to help keep a network secure. A firewall is a system designed to prevent unauthorized access to or from a private network. Firewalls can be either hardware-based, software-based, or a combination of both. Firewalls are mostly used to prevent unauthorized internet users from accessing private networks connected to the internet. There are several types of firewall techniques, such as a packet filter, an application gateway, circuit-level gateway, or a proxy server. Many firewalls use 2 or more of these techniques.

IP Addressing and Schema:

An IP Address is a code that identifies a computer network of a specific computer in a network. IP Addresses are needed so the router knows where to send the data packets in the internal network. A network mask helps you know which portion of the address identifies the network and which portion address identifies the node. There are actually 5 different classes of network, A - E, but the main 3 are A - C. Class A, B and C networks have default masks, also known as natural masks.

Class A addresses are assigned to networks with a large number of hosts. The high-order bit in a class A address is always set to 0. The next octet/seven bits complete the network ID. The remaining 24 bits (the last 3 octets) represent the host ID. This allows for 16,777,214 hosts per network and 126 networks all up.

Class B addresses are assigned to networks with a lesser number of hosts. The two high-order bits in a class B address are always set to 1 0. The next 2 octets/14 bits complete the network ID. The remaining 16 bits (the last 2 octets) represent the host ID. This allows for 65,534 hosts per network and 16,384 networks all up.

Class C addresses are assigned to networks with a small number of hosts. The three high-order bits in a class C address are always set to 1 1 0. The next 3 octets/21 bits, complete the network ID. The remaining 8 bits (the last octet) represent the host ID. This allows for 254 hosts per network, and 2,097,152 networks all up.

The User i chose was the St Johns College Network. I think St John’s college uses a class B network because, each student user has its own ID, therefore there would be more then 254 hosts (Class C), yet nowhere near 16 million. And is closer to 65,534 then either of the two.

Private IP: Can only be accessed on the LAN

Public IP: Can be accessed on the internet.

IP (Internet Protocol) enables you to send and receive data over internet connections as well as make sure they get sent to the correct destination. An IP consists of four numbers which are separated by a dot (.). Each of the four numbers can range from 0 to 255. There are two main types of IP, Dynamic and Static.

A Dynamic IP is a temporary address that is assigned to a computer each time they connect to the internet.

A Static IP is an IP that remains the same on each machine.

The Dynamic Host Configuration Protocol (DHCP) is used to configure devices which are connected to a network so that they can communicate on an IP network The router receives this information through a modem from an internet service provider which also operate DHCP servers where the modems are clients. The clients request configuration settings using the DHCP protocol such as an IP address, a default route and one or more DNS server addresses. Once the client implements these settings, the host is able to communicate on that internet.

A DNS server is any computer registered to join the Domain Name System. DNS is the name of a website you would type into your search bar. A DNS is the replacement for the IP, making it easier to remember site names, rather than finding the IP every time.

Static IP: Static IP addresses are generally used for anything that requires port forwarding (NAT). By using a static IP it makes it easy for other computers to locate and and connect to you. A Static IP is a lot less secure than a Dynamic IP because it makes connecting and locating your computer a lot easier.

Dynamic IP: Each time a device is connected to the internet it will be assigned a random IP within the IP range available. e.g. 192.168.1.2 - 192.168.1.100. These IP’s are shared among each other. Dynamic IP is a lot more secure than a Static IP because its harder to track and connect to.

A subnet is the same network with different IPs to speed up the traffic speed

Benefits of Subnets:

- It provides security.

- It allows organization of resources.

- It speeds up the network.

Using subnets will make the size of the broadcast smaller allowing data to travel to its destination much faster.