Networking and Security Assignment 2022

Running head: NETWORKING AND SECURITY
Networking and Security
Name of the Student
Name of the University
Author Note

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NETWORKING AND SECURITY
Summary of Week 2
A dedicated channel is set up in the circular switched networks before the sending of the
data. One of the examples of circuit switched networks are POTS or plain old telephone systems
that are utilized in various businesses as well as houses. Both the persons on both the ends of the
telephone can have effective connection of the wires for both the telephones covering the whole
span of the telephone call once the circuit gets established (Fan et al., 2015). The packet
switching is the process of switching of the small data blocks and is incorporated into the
network of NPL. ARPANET or advanced research projects agency network was a packet
switched network which assimilated both TCP/IP protocols and packet switching.
The internet is underpinned by both these technologies. The implementation of the
ARPANET needed those devices that had the ability of switching packets among the connected
machines. The interface message processors has the abilities for performing all the duties of the
current routers of internet (Sinha et al., 2017). This is the stage or the early start when the
internet was transformed into a packet switched internetwork of networks which underpins the
human lives. Very small packets of data can be handled internet’s network infrastructure.
The packet switching is based upon fragmentation and reassembly of the packets and is
utilized in homes, offices etc. A NIC card is required for facilitating the networking of all the
devices and routers have double network cards. Simple connectivity is the criterion of common
technologies. A framework is provided by the internet model for understanding the working of
internet. The theoretical frame of networking is defined by the OSI model (Aldosari, 2015). The
layers of the OSI model describe the networking principles. At the data link layer, the switches of
networking are operated.

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Summary of Week 3
The various user applications gives an opportunity to the users for the interaction with
various devices and services on any local network like internet. Various services of internet are
Google search engines, Facebook etc. The local level networks allows for accessing the printers,
network faxes, any network attached storage or several resources that are from the machines. The
clients are email clients, FTP clients and the web clients. The services of the servers are
requested by the clients (Yar & Steinmetz, 2019). The server awaits the requests of the clients in
the client/server network and after getting the client request, it responds to the requests made by
the clients. Strict differences are present between the roles of server and roles of the clients. The
email, file and web provider is the server and the service consumer is the client.
The code of client is different from the code of the server. Every machine within the
network have the ability act as a server or as a client in case of peer-to-peer networks that does
not need any of the dedicated servers due to the sharing of the server roles. It works well in small
networks like but the administration of networks cannot be divided into huge networks. The
architectures that are based on cloud are IaaS, PaaS, SaaSThe servers and storage is handled by
the cloud provider. The user is allowed to view the web pages by the web browser. The email
client composes and sends the email (Brown, 2019). The data of the client program should pass
through the layers of network for reaching the physical layer.
Summary of Week 4

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The data link layer makes communication with the devices on its own local network only
and it is frequently referred to as the hop to hop communication. The connection towards the
network is indicated by the NIC or the network interface card. Numerous connections are often
present in the devices. The interfaces of the network are also constructed into the scanners of the
network, printers as well as other devices (Johnson, 2016). A single NIC is connected to with the
local network or one or more than one network that are linked to the other networks contained in
the routers. A unique address of MAC or media access control is present in the networks.
The unique MAC address is constructed by the manufacturer into each and every
interface. The MAC addresses are unique globally. Each and every packet on the local network
is inspected by the network cards. The packets that belongs to the other machines are discarded.
The errors are checked by the NIC cards. The issues related to the protocols based on contention
is the occurrence of the collisions. The protocols that are utilized in these kinds of networks are
CSMA/CA which is for the wireless networks and CSMA/CD which are utilized for the Ethernet
networks (Arora et al., 2016). The request is packaged by the data link layer present on the local
personal computer.
Summary of Week 5
There are various ARP commands for observing the contents of the cache, deleting an
entry of the cache along with the deletion of all the entries of ARP. The administrative privileges
are required by some of these kinds of functions and which will never work on the machines that
are present in the lab. Addition of the new entries to the cache of the ARP can only be possible if
the ARP command is successful. This will result in a new pair of IP address/MAC address which
will be local in nature. The time changes on the basis of the operating systems (Harkin et al.,

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2018). The function of the routers is sending of the packets to the local routers which is done
with the utilization of the network or internet layer.
The role of the network layer is delivering the traffic of the network from a single host to
another host which are separated by huge distances. There are two types of IP addresses which
are IPV6 address and IPv6 address. IP address and address of the local router is required by the
machines for communicating on the IP network. The most common routing protocols include
RIP, BJP and OSPF (Karagiannis et al., 2015). The domain name system handles the resolution
of the internet names. The network ID is calculated by the subnet mask and the network ID of
every packet is contained in the IP address.
Summary of Week 6
The local devices are addressed by the data link layer through their respective MAC
addresses. The remote and the local host are addressed by the network layer by the IP addresses.
Numerous user applications are simultaneously run in the computers like email, browsers,
streaming of the videos and many more. The transport layer plays a role in ensuring that the
applications have the access to the networks which is termed as multiplexing (Heuser et al.,
2016). It also ensures that the each application must possess some difference from the other
applications which are running on certain computers. The reordering of the cases is included in
the reassembly where the packets used to get delivered out of order. The transport layer has the
ability to reassemble the data that is segmented back into the original format that is sent by the
applications concerned for sending.
A port number is allocated to each client by the transport layer for distinguishing it from
the various applications that are running on various computers. An unused port number is

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NETWORKING AND SECURITY
dynamically selected by the various user applications when they are linked to the network. Each
request is treated in the form of independent transaction by the stateless protocol which is not
related to any of the previous requests. Reliable delivery of data from the sender to the receiver is
promised by TCP. A connection must be set up before sending the data (Bello et al., 2017). The
slow receivers require a flow control for throttling the data flow from the fast senders.
Summary of Week 7
There are two types of data which are digital data and analog data. Information are stored
by the digital computers in the digital format. The videos, programs, songs, text files etc. are
stored in the binary form on the various digital media like USB devices, hard drives and many
more. Analog information like the voice data can consume infinite number of levels. The analog
signals can be digitized into the digital formats for the transmission of analog data over the
digital networks. The analog data can in turn be digitally transmitted. The transmission media
can either be digital or analog. The cables that are utilized for the connection of the computers
was built for digital data transmission.
The direct connection between the devices can be connected by the point to point circuits.
The media is shared by numerous devices by the multipoint circuits. Data can be sent only in a
single direction by the simplex systems. The communication channels are divided by
multiplexing so that the multiple conversations can be transmitted by the channel at a single time
(Liu et al., 2017). The different stations is transmitted at different point of times in the time
division multiplexing. The satellites work in the form of a relay station.

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NETWORKING AND SECURITY
Summary of Week 8
The utilization of the remote servers that are hosted on the internet for storing and
processing data in spite of PC or local network. The cloud services are made available by Google
drive, Apple iCloud etc. One of the advantage of cloud is illusion of infinite resources but are
very costly. Various technologies underpin the network of the mobile phones. The signals of the
base station gets weaker as a mobile phones makes its movement towards the perimeter cell (Rid
et al., 2015). The network of the mobile devices varies depending upon the network of the
mobile carrier.
Summary of Week 9
The confidentiality, availability and integrity of data of the computer system is protected
by the information security from the numerous malicious attacks. The body of processes and
practices for protecting the networks and programs is referred to as cyber security. Online
activity is an important part of the majority of people (Liang et al., 2018). There are various
malicious programs like auto run worm, backdoor Trojans that are harmful for the system.
The collection of the infected computers is called as botnets and are controlled by the hacker.
Numerous attacks like denial of service attacks does not let the users to access websites or
computers. Other attacks are drive by downloads, ransom ware etc. Several cyber threats are
cybercrime, cyberwarefare etc. There are mitigation strategies for countering the attacks which
can be purchase of a malware detection product. The other challenges regarding the cybercrime
is the democratic elections get disrupted.

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References
Aldosari, H. M. (2015). A proposed security layer for the Internet of things communication
reference model. Procedia Computer Science, 65, 95-98.
Arora, M., Sharma, K. K., & Chauhan, S. (2016). Cyber Crime Combating Using KeyLog
Detector tool. International Journal of Recent Research Aspects, 1-5.
Bello, O., Zeadally, S., & Badra, M. (2017). Network layer inter-operation of Device-to-Device
communication technologies in Internet of Things (IoT). Ad Hoc Networks, 57, 52-62.
Brown, C. S. (2015). Investigating and prosecuting cyber crime: Forensic dependencies and
barriers to justice. International Journal of Cyber Criminology, 9(1), 55.
Fan, W., Huang, W., Zhang, Z., Wang, Y., & Sun, D. (2015, August). A near field
communication (NFC) security model based on OSI reference model. In 2015 IEEE
Trustcom/BigDataSE/ISPA (Vol. 1, pp. 1324-1328). IEEE.
Harkin, D., Whelan, C., & Chang, L. (2018). The challenges facing specialist police cyber-crime
units: an empirical analysis. Police Practice and Research, 19(6), 519-536.
Heuser, S., Negro, M., Pendyala, P. K., & Sadeghi, A. R. (2016, February). Droidauditor:
Forensic analysis of application-layer privilege escalation attacks on android. In
Proceedings of the 20th international conference on financial cryptography and data
security (pp. 1-12).
Johnson, M. (2016). Cyber crime, security and digital intelligence. Routledge.

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Karagiannis, V., Chatzimisios, P., Vazquez-Gallego, F., & Alonso-Zarate, J. (2015). A survey on
application layer protocols for the internet of things. Transaction on IoT and Cloud
computing, 3(1), 11-17.
Liang, G., Weller, S. R., Luo, F., Zhao, J., & Dong, Z. Y. (2018). Distributed blockchain-based
data protection framework for modern power systems against cyber attacks. IEEE
Transactions on Smart Grid, 10(3), 3162-3173.
Liu, W. X., Yu, S. Z., Tan, G., & Cai, J. (2017). Information-centric networking with built-in
network coding to achieve multisource transmission at network-layer. Computer
Networks, 115, 110-128.
Rid, T., & Buchanan, B. (2015). Attributing cyber attacks. Journal of Strategic Studies, 38(1-2),
4-37.
Sinha, P., Jha, V. K., Rai, A. K., & Bhushan, B. (2017, July). Security vulnerabilities, attacks and
countermeasures in wireless sensor networks at various layers of OSI reference model: A
survey. In 2017 International Conference on Signal Processing and Communication
(ICSPC) (pp. 288-293). IEEE.
Yar, M., & Steinmetz, K. F. (2019). Cybercrime and society. SAGE Publications Limited.