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

Running head: PHYSICAL SECURITY
Physical security
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1PHYSICAL SECURITY
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.