Explain the Impact of Network Topology, Communication and Bandwidth Requirements

Client Server

This type of relationship is between two systems. One is the client (user), and the other is a server. The client will make a service request to the other system (Server) which will send back information to the client. Within this type of relationship, the client requires the information given from the server for it to function correctly; therefore, it must be managed correctly. Furthermore, the server controls the security of the network which can be beneficial as this means that the user does not need to have security measures on their side. With this type of topology, the bandwidth between the client and the server is limited by the hardware that is used either by the server or the client. (BBC, n.d.) For example, a server may have hardware supporting 1000 mb/s transfer speed but is limited to 30 mb/s due to the bandwidth allocated by the ISP (Internet Server Provider). This scenario can also be applied to the client as their hardware configuration may support higher bandwidth than their ISP (Internet Service Provider) has allocated for them.

Cloud

The cloud network topology refers to a collection of servers and data centers which are used to create a collection of resources that could be accessed from anywhere in the world as long as the user has an Internet connection. Cloud networks can be beneficial for small or large organisations as they can accompany expansion which only requires an adjustment to their current contract with the provider (Microsoft, n.d.). As a result of cloud technology, this has led to the popularisation of cloud software. Cloud software is a type of software that can be accessed through browsers. For example, Google cloud suite allows users to use a variety of software such as Docs, Slides, Sheets or Drive. These will enable users to create and edit documents, upload files and also share these documents with other users through email. This can be advantageous for organisations as this can be used to improve communication and also allows employees to continue working on documents outside of business hours.

Virtualised

Virtualised networks can be presented in a variety of different forms that work in a variety of ways and for a different purpose. VLAN stands for Virtual Local Area Network. Cisco (URL, n.d.) summarises a VLAN as a “group of devices on one or more LANs that are configured to communicate as if they were attached to the same wire”. Within an organisation this can be beneficial as the connecting LANs could allow for increased communication between departments or branches, therefore. Another type of Virtual network is a VPN. This stands for a virtual private network which according to Cisco (n.d. 2) is defined as “an encrypted connection over the Internet from a device to a network”. This can also be known as remote access. Within an organisation that allows employees to connect to the network securely. This can be beneficial as it can enable the work from home approach which could prevent demotivation.

Logical Topology

Ethernet

The Ethernet typology is the most typical type of logical topology used. This topology can use two physical topologies that are the bus and the star topology. The bus topology connects all devices on the network through the same medium, also known as a physical channel. Some examples of this physical channel are coaxial Cables, twisted pair or fibre optic. When using this topology, any communication that occurs can be heard by all other devices connected (Blackbox, n.d.). Ethernet also utilises CSMA/CD which stands for Carrier Sense Multiple Access with Collision Detection. Carrier Sense refers to the prevention of transmission from other devices if one is already transmitting (Blackbox, n.d.). Multiple Access refers to the ability for multiple devices to communicate using the same medium (Blackbox, n.d.). Collision Detection refers to a check that occurs to detect if more than one transmission signal is occurring, jamming the signal and then waiting for a random interval before retransmission. (Blackbox, n.d.)

Physical Topology

Star

BBC (n.d. 3) defines the star network topology as “each device on the network has its own cable that connects to a switch or hub”. This means that visually the switch/hub is located at the centre of and the computers are connected to the hub/switch rather than being connected to two different computers. This can be essential for network management as all the traffic will be directed through the switch/hub which it can be easily managed. Similar to other types of topologies it is also easy to add devices to the network as it will only require a cable connected to the switch/hub. If a device other than the hub/switch fails, then the rest of the network will still be accessible. However, if the hub/switch fails, then the entire network will not be accessible by the other devices. This also has additional cost due to the requirement of a networking device to be used. (BBC, n.d. 3).

Ring

According to ComputerHope (2018), the ring topology is defined as “A ring topology is a network configuration in which device connections create a circular data path. Each networked device is connected to two others, like points on a circle”. From this, it can be assumed that in the event of an error occurring at one part of the ring this will cause the chain to break and the network to fail. The ring topology also only allows transmission in a certain direction at a certain time within the circle while other topologies such as the star allows the data to flow in either direction. Unlike the star topology, it does not require a networking device for it to function correctly as each device will connect to two other devices. This also allows the network to be flexible. It can expand the ring as long as the new device can connect to two other devices to continue the ring. Furthermore, as the data is travelling in one direction, this can reduce collisions that occur when transmissions are sent. However, this topology can be slow. For example, if a device has to transmit data to a device that is “behind” it on the ring, it will have to go to every other device before it reaches its destination. (Computerhope, 2018).

IPv4

IPv4 stands for Internet Protocol Version 4 which is a 32-bit IP address that is formatted as four three-digit numbers separated by a dot. For example, 111.111.111.111. This can allow any number from 0 to 255 which roughly provides 4 billion unique addresses. As computing devices have become more affordable, it had led to it becoming more common in everyday houses and organisations. As IPv4 has a set limitation on the number of unique addresses it can allocate, it will mean that at in the future we will run out of unique addresses. To solve this major issue, a new type of unique address will be used as a replacement to the IPv4 system. This is called IPv6. (PC, 2009)

IPv6

IPv6 is the 6th version of the Internet Protocol which is an increasingly complex version from an earlier version. This is because it uses a 128-bit address which is four hexadecimal (0-9 and A-F) numbers laid out in the following pattern ‘aaaa:bbbb:cccc:dddd:eeee:ffff:gggg:hhhh’. As this follows hexadecimal, this can be easily perceived as being more secure as attempting to guess the IP would take significantly more time than what it would for an IPv4 address. This type of Internet Protocol has not been fully adopted yet. This is due to a wide range of systems using IPv4, and the immediate switch could be financially expensive. However, as of the 22d November 2018, there is a 22.77% IPv6 adoption with 21.85% of the amount being in the United Kingdom. (Google, n.d.)

FTP

FTP stands for File Transfer Protocol and it is used for transferring files between a client and a server. This type of protocol utilises the client-server network topology when communicating between the server and the client. FTP also uses two ports, one for sending data (port 20) and another port for the server to listen for incoming clients (port 21) (Gibson Research Corporation, 2008). FTP can also be handy for a user as this allows them to easily upload and download files remotely through the connection which further eliminates the requirements for the user to use a removable media to merely update the files on their server. Depending on the configuration this also means that it can also be remotely accessed from different geolocations. FTP is commonly used when using a company as a server hosting provider as most times the servers are not physically accessible the user. (BBC, n.d. 2)

HTTP

HTTP stands for HyperText Transfer Protocol which is used for transmitting digital media for example HTML. This protocol is used when sending requests from a browser to a web server. This type of protocol is stateless which is defined as not recording any data. This type of transmission protocol has been superseded by HTTPS which is a secure version of the HTTP protocol. HTTPS is a secure version of HTTP which utilises encryption methods to ensure any data transmitted or received by the user cannot be intercepted. (BBC, n.d. 2)

OSI Model

OSI stands for Open Systems Interconnection. According to (CloudFlare, n.d.) the OSI provides “Standardization which enables diverse communication systems to communicate using standard protocols.”

Layer 7

Layer 7 also known as the Application layer. This layer interacts with the user and is used to establish the communication. This layer gains this communication from software applications which rely on protocols for communicating data and also receiving data (Cloudflare, n.d.). A common example of this is the HTTP protocol as the user requests a web page from a browser which in turn attempts to establish communication with the server. Another typical example is the usage of FTP. As the software relies on communicating with the server for the purpose of sending and receiving files.

Layer 6

Layer 6 also known as the Presentation layer. This layer specialises in translation of data so that the different layers can use it. This means that any information passed from the application layer will need to be translated so it can be readable by another device. This also works in the opposite direction as data from another device will not be readable by the application layer. Therefore, it will need to be translated into a format that can be used by the application layer. Furthermore, encryption, decryption, and compression are also done during this stage if required. (Cloudflare, n.d.)

Layer 5

Layer 5 also known as the Session layer. This layer has the primary focus of managing the communication between the two devices that are used for the transmission and receiving of data. This layer also has the ability to establish and terminate the communication. This layer is essential as it ensures that communication between the two devices is established long enough for the data to be fully transmitted without any errors. To further ensure that the data is fully transmitted, checks are conducted periodically to identify the recipient or sender has disconnected. If this occurs, the layer will save the last point that data was transmitted or received so that it only sends the missing packets rather than all of them. (Cloudflare, n.d.)

Layer 4

Layer 4 also known as the Transport layer. This focuses on taking data gained from the session layer then breaking it into segments which will then be given to the network layer (layer 3). This layer is also responsible for the data communication for the two devices. This contains flow and error control which will identify the transmission speed required so that it does not cause issues for the recipient if they have a lower speed than the sender. Error control ensures that all data is sent correctly and if it is not correctly sent it will retransmit the missing data. (Cloudflare, n.d.)

Layer 3

Layer 3, also known as the Network layer. This layer is designed to transfer the data from one network to another. This layer is only applicable if the two devices are not contained on the same network as this layer will be skipped and sent to layer 2. During the network layer, the segments gained from the previous layer are then further split into packets. These contain the data and information such as the receiver’s IP address to allow it to get to the correct location.

Layer 2

Layer 2, also known as the Data Link layer, refers to the section which specialises in the transmitting and receiving of data between two devices that are connected within the same network. This takes the packets received from layer three that do not contain information in relation to which local machine requested the data. This then adds the MAC address to the packet so it can be correctly forwarded to the right system. As with the network layer, this also contains flow control and error control functionality to ensure the data is received correctly. (Cloudflare, n.d.)

Layer 1

Layer1, also known as the physical layer, refers to the use of physical equipment that is required for data to be transferred successfully. This is typically done through mediums such as an Ethernet cable. During this layer, the data gets converted into bits which consist of 1s and 0s. When communicating between devices, these must be correctly synchronised to understand the data conversion. (Cloudflare, n.d.)

IEEE 802.3

10Base-T

10Base-T is an Ethernet standard established by the IEEE. Sopto (n.d.) defines 10Base-T as “10BASE-T is the IEEE standard that defines the requirement for sending information at 10 Mbps on unshielded twisted-pair cabling”. This means that when using a 10Base-T wire for connecting devices together will only allow a transmission speed of 10 Mbps.

100Base-TX

According to Pcmag (n.d.), 100Base-TX is a modified version of 100Base-T which supports transmission speeds of 100 Mbps between devices using two pairs of category 5 cables while the 100Base-TX utilizes the Category 6 cables.

1000Base-T

1000Base-T is an updated standard by the IEE which is defined by Sopto (n.d.) as “sending information at 1000 Mbps on unshielded twisted-pair cabling”. This type of Ethernet is an updated version of 10Base-T but allows for significantly faster transmission speeds of 1 gigabit. This also utilizes Category 5 cables within which will enable it to have the 1 gigabit transmission speed. (Sopto n.d.)

10GBase-T

According to an article published by Cablinginstall (2006), 10GBase-T refers to a standard for ethernet that supports the ability to have 10 gigabits per second transmission speeds up to 100 meters. This is further expanded by the usage of Category 6 Augmented cables (Cat 6a) which allow these speeds to be used for distances over 100 meters. This type of Even though this was first established in 2006 it is still uncommon for the standard household. This is because a lot of ISPs and consumer level hardware do not support those types of speeds. However, this is used by large organisations that conduct large-scale file transfers and receiving. This is also common within data centers as they are reliant on maintaining high transmissions speeds.

IEEE 802.11

IEEE 802.11 refers to the working standards set for Wireless Local Area Networks created by the Institute of Electrical and Electronics Engineers (IEEE). This also sets specifications for the Media Access Control (MAC) and the Physical Layer (PHY). The first version of these standards was released in 1997 and has been amended and updated as wireless technology advances. Below contains some of the examples of the various protocols that are set by the IEEE. (Mitchell, 2018)

802.11a

This iteration of the 802.11a wireless standard sough to improve upon the original networking speed of 1-2Mbps transmission. This was upgraded to 54Mbps and also utilized the 5GHz band, standard 802.11 utilised 2.4GHz. This also made sure it would be compatible with other iterations of the wireless standard such as the 802.11b and 802.11g. (Mitchell, 2018)

802.11b

This standard also is adapted from the original 802.11 standard but focuses on improvements within the 2.4GHz range which increased the transmission speeds to 11 Mbps. This further allowed wireless to be more viable as an alternative to ethernet.  (Mitchell, 2018)

802.11g

This type of wireless standard is the most commonly used one today. This further expands on the 802.11b wireless standard by allowing transmission speeds up to 54Mbps and distances up to 150 feet (45.72 Meters). It also still uses the 2.4GHz range which allows it to be compatible with the 802.11b wireless standard. (Mitchell, 2018)

802.11n

This wireless standard was designed to be an improvement over the 802.11g wireless standard. This utilises MIMO technology, which stands for Multiple Input, Multiple Output. This allows the access point to use more than one antenna which can improve speed, range, and overall efficiency. (Mitchell, 2018)

802.11ac

802.11ac was created as an overall improvement to the 802.11 standard but more specifically the 802.11n wireless standard. This wireless standard provides significantly increased transmission speeds (from 433 Mbps). This also runs on the 5GHz range to ensure speed is maintained as most other devices run on the 2.4GHz range. This also incorporates the MIMO technology and also uses a new technology called beamforming. Which according to Lendino (2016) “sends signal directly to client devices”.

REFERENCES

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