Understanding TCP/IP Network Protocols

This assignment delves into the intricacies of TCP/IP network protocols, with a particular focus on the User Datagram Protocol (UDP). It requires students to analyze various aspects of UDP, including its role, functionality, advantages, and limitations. The assignment also touches upon related concepts like error recovery in wireless networks, IP payload compression, and congestion control in data center networks.

Running head: SECURING DIGITAL INFRASTRUCTURE
Securing Digital Infrastructure
Name of the Student:
Name of the University:
Author note:

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Table of Contents
Week 11.....................................................................................................................................2
Access Control Matrix...........................................................................................................2
Week 12.....................................................................................................................................3
Answer 1................................................................................................................................3
Answer 2................................................................................................................................3
Answer 3................................................................................................................................4
Answer 4................................................................................................................................4
Answer 5................................................................................................................................5
Answer 6................................................................................................................................5
Answer 7................................................................................................................................6
Answer 8................................................................................................................................6
Answer 9................................................................................................................................7
Answer 10..............................................................................................................................7
Answer 11..............................................................................................................................8
Answer 12..............................................................................................................................8
Answer 13..............................................................................................................................8
Answer 14..............................................................................................................................9

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Answer 15..............................................................................................................................9
Answer 16..............................................................................................................................9

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Week 11
Access Control Matrix
Review
end
user
account
request
Approve
end user
account
request
Create
end
user
account
Audit
end user
accounts
Review
end
user file
server
access
request
Approve
end user
file server
access
request
Perform
end user
file server
access
change
Audit end
user file
system
permissions
System
Engineer 1
Yes
System
Engineer 2
Yes Yes
Network
Administrator
Yes Yes
System
Engineering
Manager
Yes Yes
Security
Administrator
1
Yes
Security
Administrator
2
Yes Yes
Security
Manager
Yes Yes

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IT Manager Yes
Week 12
Answer 1
The following URL is being followed for answering the questions on RFC 793 from
the upcoming sections: https://tools.ietf.org/html/rfc793
Answer 2
The Tools.ietf.org5 (2017), states that TCP ensures reliability in Internet Protocol as
transmission is made reliable via the following processes:
 Unique Sequencing - The TCP marks each packet with unique sequence number so as
to keep track of all packets. This keeps track of which packets are lost in the
transmission.
 Acknowledgements (ACK/NACK) - TCP has this mechanism to check whether every
packet that was released from the transmission end has been received at the reception
end. It does so with the help of a strict order of (ACK/NACK) acknowledgement/non-
acknowledgement signals, and strict timeout windows.
 Timeout based retransmission – If the acknowledgement is not received before
timeout, the octet or data packets are retransmitted (Wu et al., 2013).
 Damage Control - Damage is handled by the addition of a checksum to every
transmitted segment, thus checking it at the receiver. This helps in discarding the
damaged segments.
 Three-way handshake - The TCP uses the three-way handshake method to create a
secure connection between the local host and the server. This method requires both

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the host and the server to exchange Synchronize (SYN) and Acknowledgement
(ACK) packets before the actual communication is started.
 Error recovery – The TCP has the capability to recover from internet communication
system errors (Kliazovich, Redana and Granelli, 2012).
Answer 3
An octet is known the unit of digital information. In telecommunications and
computing, octet consists of eight bits. An octet’s value has its mathematical range from 0 to
255. However, a collection of related octets is known as an octet string. These are commonly
found in IP (Internet Protocol) addressing, where 4-bytes of IPv4 addresses consist of 4
octets. In the dotted decimal notation, the IP address with octets is represented as below:
<octet> . <octet> . <octet> . <octet> for example, 292.238.0.1. However, the IPv6 contains
16 octets instead of 4. Octets are also capable of referring to individual byte units, within the
network protocol’s headers and footers. Octets also help in the reliable transmission of data
(Shacham et al., 2001).
Answer 4
In order to control the flow of data between the TCPs, the networking system employs
a flow-control mechanism. As an acknowledgement, the receiving TCP reports a ‘window’ to
the sending TCP. These windows specify the total number of octets that the receiving TCP is
presently ready to receive. The window message starts with the acknowledgement number of
the transmission as well. If the window size reported is zero, it means that the transmitting
system needs to wait for an acknowledgment before it can send its next chunk of data.
However, if the window reports a buffer size that is larger than the size of a single data
packet, it depicts that the system can send multiple data packets without having to wait for

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the acknowledgement. This makes data transfer faster and more efficient (Tools.ietf.org5,
2017).
Answer 5
A full-duplex connection states that data can be transmitted in both directions,
simultaneously. TCP establishes a full-duplex circuit between the transmitting hosts so that
both can put data on the Internet simultaneously, without having to specify the destination
host, once the connection is established. For example, in a LAN connection that is armed
with the full duplex technology, a workstation may send data on the line while another is
sending its data as well, at the same time. It is also known as a bi-directional type of
communication system. These types of system are constituted of two channels. Each of which
are responsible for transmitting data in their respectively opposite directions (Comer, 2015).
Answer 6
The data communication system section form the RFC 793 defines the importance of
the PUSH flag in the transmission of data packets. The SEND calls from the sending users
carries the PUSH flag to denote if the data that it holds is to be sent to the receiver
immediately. Setting of the PUSH flag will help in doing so. The sending TCP is meant to
collect data as long as it does not encounter the PUSH flag. Then it has got to push send all
its data to the receiver. Similarly, the receiver TCP will stop waiting for more data and push
all its data to the receiver process. Even if the receiving process’ buffer is not filled, it must
send through all its data into the receiving process on encountering the PUSH flag (Davidson,
2012).
In Tools.ietf.org6 (2017), the Nagle’s Algorithm, also known as nagling increases the
efficiency of network systems by reducing the number of packets to be sent. The algorithm

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was initially designed to relive the private TCP/IP networks off the burden of congestion.
Inserting two lines of code into a TCP program generally implements Nagle’s algorithm. The
codes instruct the sender process to buffer data if there is a presence of unacknowledged data,
outstanding. Data that is sent next, is held until the waiting data is acknowledged or until
there is data to send, that is worth a full packet.
Therefore, the Nagle’s Algorithm aims at reducing the number of packets being sent.
This improves the efficiency of the PUSH flag from RFC 793. This algorithm however
emphasizes on the sender buffering its output until it is full.
Answer 7
To provide security and precedence to the TCP users, the TCP uses the Internet
Protocol type of services and its security options. TCP modules that operate in the multilevel
secured environment are needed to mark the outgoing segments with security, precedence
and compartment tags. The levels of the same should also be mentioned to the users of the
TCP. The methods mentioned here are still in use today. All users on the TCP/IP connection
have their respective security label, which is associated with the IP address, defined on
server. If users need a different security label, they must enter through an IP address having
that particular security label (Tools.ietf.org5, 2017).
Answer 8
The concept of using sequence numbers is a major leap in TCP. Each octet that is sent
over the TCP is assigned a specific sequence number. This helps the receiver to acknowledge
each octet. This is a cumulative approach as it states that on acknowledging a sequence
number-X, all the octets prior to that have been received.

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This mechanism also helps in ruling out the possibilities of the presence of any
duplicate octet. The sequence number space is not infinite, however it is large enough. The
space ranges from 0 to (2^32-1). The space being finite makes the sequencing to be done
based on the modulo of 2^32 (Tools.ietf.org5, 2017).
Answer 9
The TCP/IP network uses the three-way handshake method to create a connection
between the local host and the server. This method requires both the host and the server to
exchange Synchronize (SYN) and Acknowledgement (ACK) packets before the actual
communication is started. The Three Way Handshake is also known as TCP-handshake. This
method is necessary because the sequence numbers are not generally tied to the global clock
on the network.
When an established connection is aborted or closed by one of the existing TCPs
without the knowledge of the other, it is termed as a Half-Open connection. However, a
scenario where both ends of a connection has gone desynchronized due to a crash and
resulted in the loss of memory, it may also be termed as a half-opened connection (Rana,
Garg, and Chamoli, 2012).
Answer 10
According to Tools.ietf.org3 (2017), TCP is the abbreviation for Transmission
Control Protocol where as UDP stands for User Datagram Protocol. The primary difference
between them is that TCP is a connection-oriented protocol, whereas UDP is connectionless.
After setting up the connection, the TCP allows a bidirectional sending of data while in UDP,
packets must be sent in chunks. UDP is faster than UDP; however, TCP is more reliable as
compared to UDP. The UDP does not guarantee delivery and duplicate protection; therefore,

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it makes it less reliable. The TCP header size is 20 bytes whereas; the header size of UDP is 8
bytes.
The lack of policies to keep check over the duplication of data packets and to ensure
data delivery makes the UDP RFC shorter than that of TCP’s. The UDP protocol assumes
that the Internet Protocol is running as an underlying support and therefore it is necessary
protocols are overlooked.
Answer 11
The RFC mentions that the UDP protocol is majorly used in the Trivial File Transfer
mechanism and the Internet Name Server. However, since it is a faster mechanism, UDP has
found its uses in the modern times as well. Media streaming, Gaming and Tunneling or VPN
technologies uses this protocol vastly. These technologies do not care about the loss of data
packets but the speed of transmission is all that matters. Therefore, its use is critical in this
case (Shirmohammadi et al., 2015).
Answer 12
The author in the Tools.ietf.org4 (2017), states that the ICMP or the Internet Control
Message Protocol is a supporting protocol integrated to the IP suite. Network devices use it in
order to report error messages and other operational information. These control messages are
needed to provide feedback about the issues in the communication environment . This does
not make Internet Protocol reliable.
Answer 13
ICMP is blocked by firewalls due to the following reasons:

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 Protect the network from old-style worms, which attempt to infiltrate using the echo
request of the ICMP (Khule, Singh and Kulhare, 2014).
 The DoS (Denial of Service) attacks are generally based on ICMP (Anand and Patel,
2012).
Answer 14
The Avian Carriers is a high delay and low throughput method for the transmission of
IP datagram, when compared to TCP. This method has a response time of approximately
3000 to 6000 seconds (Judge, 2013).
Answer 15
The Avian Carriers mechanism must ensure special security measures in the process
of transmission of IP. The TCP model has multiple levels of security to make its data flow
reliable, which is lacking in this method. The datagram sent over the Aviation Carriers must
be encrypted, to rule out the risk of discovery by unwanted individuals in between the
process. Moreover, the TCP ensures the delivery of packets through its various mechanisms
where as this process cannot guarantee the same (Tools.ietf.org1, 2017).
Answer 16
The four types of documents or specifications that the author postulates through the
International Monkey Protocol Suit (IMPS) are:
 KEEPER Specification- KIMP is the abbreviation for Knowledgeable and Efficient
Emulation Protocol for Ecosystem Resources. The Zone Operations Organizations
(ZOO) uses this in communicating with the Semi-Integrated, Monkey-Interfacing
Anthropomorphic Node (SIMIAN). The ZOO sends requests to the SIMIAN using an

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IMPS packet. The SIMIAN then sends responses back to the ZOO with a different
packet. KEEPER is a connectionless protocol. The IMPS protocol ID for this is 1.
 CHIMP Specification- The Cross-Habitat Idiomatic Message Protocol is used by the
SIMIAN to communicate with the ZOO. The IMPS protocol ID for this is 2. This is
meant to be a connection-oriented protocol where the client sends a series of requests
to the server and waits for it to reply back.
 IAMB-PENT Specification- Inter-Annex Message Broadcasting Protocol for
Evaluating Neoclassical Transcripts is the postulated specification that the ZOO uses
in order to send transcripts to the Big Annex of Reference Documents (BARD). Its
IMPS protocol number is 5. This too is a connection oriented protocol where the
client sends transcript phrases to the server. The server further evaluates the transcript.
It then notifies the client whether the received transcript matches to the classical work.
 PAN Specification- PAN stands for Protocol for Assessment of Novelty. The ZOO
uses the PAN to send the monkey transcripts to the Collective Reviewer's Innovative
Transcript Integration Center (CRITIC) for review. The CRITIC being the all-
powerful controller is sent requests from the ZOO and it further responds back. This
too is connection oriented protocol. PAN’s IMPS protocol number is 10
(Tools.ietf.org2, 2017).

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References
Anand, A. and Patel, B., 2012. An overview on intrusion detection system and types of
attacks it can detect considering different protocols. International Journal of Advanced
Research in Computer Science and Software Engineering, 2(8).
Comer, D., 2015. Computer networks and internets. Pearson.
Davidson, J., 2012. An introduction to TCP/IP. Springer Science & Business Media.
Judge, A., 2013. Circumventing Invasive Internet Surveillance with Carrier Pigeons.
Khule, M., Singh, M. and Kulhare, D., 2014. Enhanced worms detection by
Netflow. International Journal of Engineering and Computer Science, 3(3), pp.5123-7.
Kliazovich, D., Redana, S. and Granelli, F., 2012. Cross‐layer error recovery in wireless
access networks: The ARQ proxy approach. International Journal of Communication
Systems, 25(4), pp.461-477.
Rana, D.S., Garg, N. and Chamoli, S.K., 2012. A Study and Detection of TCP SYN Flood
Attacks with IP spoofing and its Mitigations. International Journal of Computer Technology
and Applications, 3(4).
Shacham, A., Thomas, M., Pereira, R. and Monsour, B., 2001. IP payload compression
protocol (IPComp). Consultant.
Shirmohammadi, S., Abdallah, M., Ahmed, D.T., Lu, Y. and Snyatkov, A., 2015.
Introduction to the special section on visual computing in the cloud: Cloud gaming and
virtualization. IEEE Transactions on Circuits and Systems for Video Technology, 25(12),
pp.1955-1959.

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Tools.ietf.org1. (2017). RFC 1149 - User Datagram Protocol. [online] Available at:
https://tools.ietf.org/html/rfc768 [Accessed 20 Nov. 2017].
Tools.ietf.org2. (2017). RFC 2795 - User Datagram Protocol. [online] Available at:
https://tools.ietf.org/html/rfc768 [Accessed 20 Nov. 2017].
Tools.ietf.org3. (2017). RFC 768 - User Datagram Protocol. [online] Available at:
https://tools.ietf.org/html/rfc768 [Accessed 20 Nov. 2017].
Tools.ietf.org4. (2017). RFC 792 - User Datagram Protocol. [online] Available at:
https://tools.ietf.org/html/rfc768 [Accessed 20 Nov. 2017].
Tools.ietf.org5. (2017). RFC 793 - Transmission Control Protocol. [online] Available at:
https://tools.ietf.org/html/rfc793 [Accessed 20 Nov. 2017].
Tools.ietf.org6. (2017). RFC 896 - User Datagram Protocol. [online] Available at:
https://tools.ietf.org/html/rfc768 [Accessed 20 Nov. 2017].
Wu, H., Feng, Z., Guo, C. and Zhang, Y., 2013. ICTCP: Incast congestion control for TCP in
data-center networks. IEEE/ACM transactions on networking, 21(2), pp.345-358.