Physical Security: ARPANET, TCP/IP Protocol, Process Control Networks, LAN, WAN and VPN

This article discusses the first computerized network ARPANET, its advantages and disadvantages, TCP/IP protocol, Process Control Networks, LAN, WAN and VPN.

Running head: PHYSICAL SECURITY
Physical security
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Question 1: Description about first computerized network and its origin.
Advanced Research Projects Agency Network or ARPANET was the first established
computer-to-computer link. It was established in the year 1969 (Haigh, Russell, & Dutton
2015). The day was October 29. It was a project and was funded by Advanced Research
Projects Agency known as the ARPA, which is now known as DARPA. It falls under the
purview of United States Department of Defense. ARPANET was used for projects at
laboratories and at universities in the United States. Lawrence Roberts and British scientist
Donald Davies of Lincoln laboratory designed ARPANET’s packet switching (Campbell &
Garcia, 2013). An UCLA student Charles S Kline sent the first message on the ARPANET at
sharply 10:30 pm on the day of October 29. The word ‘LOGIN’ was meant to be transmitted
via the ARPANET but only the letter ‘L’ and ‘O’ was transmitted before the system crashed.
The system was recovered after about an hour and then in the second transmission the full
word was sent. ARPANET link was permanently established on November 21 in the year
1969. Entire four-node network was established on December 5 in the year 1969. ARPANET
became operational in the year 1975 and then the Defense agency of the US took control of it.
Question 2: Advantages and Disadvantages of ARPANET.
ARPANET that was created before the invention of internet has certain advantages.
ARPANET team took an important decision for the creation of standardized system of
protocols with the intention that host computers would follow these protocols. This system
allowed remote login and after login, users were able to move files from one computer to
another (Garden & Development, 2018). Remote login was later given a name Telnet.
Transmission or transfer of files from one machine to the other and vice versa became a part
of FTP (File Transfer protocol). ARPANET made use of host-to-host protocol known as NCP

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(Network Control Program) which allowed communication between the computers within the
network and allowed addition of more hosts. ARPANET used packet switching to send data.
This section will state few disadvantages of ARPANET. The first disadvantage was
that connection to any non-SNA (System network architecture) networks was quite difficult.
Alternate pathways between pair of nodes were predesigned and had to be stored centrally.
This was ARPANET’s second disadvantage (Campbell & Garcia, 2013). The third
disadvantage that was found out that maintenance and installation of SNA networks were
complicated. SNA network products were also found to be expensive.
Question 3: One of the significant advantages of combining TCP/IP protocol.
Transmission Control Protocol abbreviated as TCP is a set of communication
protocols. It was developed by DARPA (Defense Advanced Research Projects Agency) in
the year 1970. TCP/IP protocol was used in ARPANET and then it was developed further to
be used on the internet. Any computer that connects to the internet uses this protocol. One of
the advantages is standardization. A computer communicates with another computer by a
language that can be understood by the computer at the receiving end. This language is the
communication protocol. This TCP/IP protocol standardizes this communication process. It is
standardized since it offers only one universal protocol for all computers to communicate
with one another. Interoperability is another feature of TCP/IP protocol ("Advantages of the
TCP/IP Protocol | Techwalla.com", 2018). Computers can use other languages for
communication with one another. Private networks can use other protocols. The astonishing
part of TCP/IP protocol is that it enables such networks to connect to the internet. Computer
systems having different architecture and hardware can communicate with other computers
using the TCP/IP protocol. This is known as interoperability. Each computer on the network
is assigned a unique address known as the IP address. This is done by the TCP/IP protocol.

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Question 4: Explanation of Process Control Networks.
PCN or (Process Control Network) is a network that is used for communications. Data
and instructions are transmitted between measurement and control units and between data
acquisition equipment and supervisory control (Galloway & Hancke, 2013).
Over the years, this type of network has borrowed topologies and technologies
utilized in other network applications. PCN or Process Control Networks possesses special
requirements, which must be met so that the solution is acceptable to industry. Special
requirements can be divided into Determinacy, Compatibility and Robustness. Under
robustness, requirements include reduced sensitivity EM interference, redundancy and error
correction. For determinacy, every device is assured that access to the network is guaranteed
for them. Compatibility allows DCS (Distributed Control systems) from different
manufacturers to communicate with measurement and control equipment (Christofides et al.,
2013). PSNs can be used for all types of environment. PCNs that were set up early were
serial based and they used low-level standard such as EIA RS-485. It now uses Modbus
standard. Since Process Control Networks are deterministic, they use token passing based
protocols. Most PCNs (Process Control Networks) rely on TCP/IP, Ethernet and Microsoft
windows technology.
Question 5: Explanation of LAN, WAN and VPN.
LAN- Local area network is abbreviated as LAN. In a LAN, a group of computers
shares wireless link or a common communication link to a private server. A local area
network encompasses peripherals and computers that are connected to a private server within
a specific geographical area such as college or office. The size of local area network can vary.
Users can be as few as two or three or multiple users can be there ("What is local area
network (LAN)? - Definition from WhatIs.com", 2018).

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WAN- Wide area network is abbreviated as WAN. It can be termed as a distributed
network that is able to interconnect several local area networks. For an enterprise, wide area
network may connect headquarter of a company, facilities, branch offices and other facilities.
A router can be used to interconnect LAN to a wide area network ("What is WAN (wide area
network)? - Definition from WhatIs.com", 2018).
VPN: Virtual proxy network is abbreviated as VPN. VPN is extended across shared or
public network. The main purpose of virtual proxy network is to act like a cauldron where
data can be exchanged anonymously and securely over the internet. Information traversing
between a VPN server and connected devices is encrypted (Chung et al., 2013). Thus,
applications that runs on the virtual proxy network benefit immensely from functionality,
strength and security of the network.

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References:
Advantages of the TCP/IP Protocol | Techwalla.com. (2018). Techwalla. Retrieved 11 April
2018, from https://www.techwalla.com/articles/advantages-of-the-tcpip-protocol
Campbell-Kelly, M., & Garcia-Swartz, D. D. (2013). The history of the internet: the missing
narratives. Journal of Information Technology, 28(1), 18-33.
Christofides, P. D., Scattolini, R., de la Pena, D. M., & Liu, J. (2013). Distributed model
predictive control: A tutorial review and future research directions. Computers &
Chemical Engineering, 51, 21-41.
Chung, C. J., Khatkar, P., Xing, T., Lee, J., & Huang, D. (2013). NICE: Network intrusion
detection and countermeasure selection in virtual network systems. IEEE transactions
on dependable and secure computing, 10(4), 198-211.
Galloway, B., & Hancke, G. P. (2013). Introduction to industrial control networks. IEEE
Communications Surveys and Tutorials, 15(2), 860-880.
Garden, H., & Development, W. (2018). How ARPANET Works. HowStuffWorks. Retrieved
11 April 2018, from https://computer.howstuffworks.com/arpanet2.htm
Haigh, T., Russell, A. L., & Dutton, W. H. (2015). Histories of the Internet: Introducing a
special issue of information & culture. Information & Culture, 50(2), 143-159.
What is local area network (LAN)? - Definition from WhatIs.com. (2018). SearchNetworking.
Retrieved 11 April 2018, from
https://searchnetworking.techtarget.com/definition/local-area-network-LAN

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What is WAN (wide area network)? - Definition from WhatIs.com.
(2018). SearchEnterpriseWAN. Retrieved 11 April 2018, from
https://searchenterprisewan.techtarget.com/definition/WAN