COIT20261 Network Routing and Switching (Term 1, 2018) Assignment

This document provides a comprehensive solution to a network routing and switching assignment (COIT20261, Term 1, 2018). The assignment covers several key concepts including routing table analysis, packet fragmentation calculations, and the BBR congestion control algorithm. Question 1 focuses on analyzing routing tables and determining next-hop addresses for data packets, including understanding prefix networks, next-hop addresses, and interface utilization. Question 2 involves calculating packet fragmentation parameters, determining the number of fragments, and calculating offset values for each fragment. Question 3 delves into the BBR algorithm, discussing its role in optimizing TCP/IP performance, addressing congestion issues, and comparing it to traditional TCP congestion control mechanisms. The solution references relevant resources, including the BBR Congestion Control IETF draft and a Network World article on Google's implementation of BBR.

COIT20261 Network Routing and Switching (Term 1, 2018)
Assignment item —Written Assessment-2
First Name:_________________________ Last Name:____________________________
Student ID: __________________________
Question Number Mark
allocated
Marks
earned
Question 1: (10 marks)
1.
2.
3.
4.
5.
6.
7.
8.
For the R4 router 150.3.0.2 is the next hop for the data packet to have
161.22.0.15/18
For the R1 router the interface utilized for sending the packet to the
network 161.22.0.0/18 is M2.
At the point when a packet is sent between 200.11.60.36/24 and
150.32.0.240/18 2 hop address should be used for reaching the destination
network.
In the event that an information packet produced from the source
200.11.60.36/24 achieves the R1 router and the router does not finds the
goal address in the routing table it drops the information parcel.
On the off chance that with the goal address 140.21.0.10/22 achieves the
router R2 the interface M0 is utilized for sending the information parcel.
The goal address of the packet at R3 router is 220.10.40.5/24 the next hop
address for sending the information bundle would be 150.3.0.3/16
For the data packet looking out for the R4 router and if the following hop
is an immediate conveyance the system 150.3.0.0/16 is the goal address.
q.8 Routing table of router R2:
For the analysis of the routing table the IP address assigned to the
interface of the other routers and its interface is analysed and the
following table is created
Prefix Network
address
Next-hop
address
Interfac
e
255.255.255.0 220.10.40.0 150.3.0.3 M0
255.255.192.0 161.22.0.0 150.3.0.3 M0
1-7 1
mark
each, q.8
3 marks

COIT20261 Network Routing and Switching (Term 1, 2018)
Assignment item —Written Assessment-2
255.255.192.0 150.32.0.0 150.3.0.1 M0
255.255.0.0 150.3.0.0 150.3.0.2 loopback
Question 2: (5 marks)
a) Number of packet fragments = (total size of packet) / (Maximum
Transmission Unit)
= 5400/ 1500
= 3.6
= 4
Thus, Datagram with data 5400 byte fragmented into 4 fragments.
For the 1st frame:
It carries bytes 0 to 1479 (MTU = 1500 bytes and header length = 20
byte)
Thus, the total bytes in fragments is maximum 1500-20 =1480
For the 2nd frame:
It carries bytes 1480 to 2959.
For the 3rd fragment:
It carries byte 2960 to 4439.
For the 4th fragement:
It carries bytes 4440 to 5400
2.5
b) Offset value of the 1st packet fragmentation = 0
Offset value of the 2nd packet fragmentation = 185
Offset value of the 3rd packet fragmentation = 370
Offset value of the 4th packet fragmentation = 555
1.5
c) IP addresses mainly comes up with 20 bytes of information. It mainly
bundles up various kinds of header records. The extent of the provide
packet is mainly decreased to 20 bytes when it is contrasted with diagram
from the past. For proper kind of aggregation of number of information
1

COIT20261 Network Routing and Switching (Term 1, 2018)
Assignment item —Written Assessment-2
bytes is mainly stored in 1500 bytes. It is mainly used in bytes for second
bundle is of value 1480 on grounds. It mainly comes up 20 bytes in length
which is present in the header and second bundle is mainly stored in 1480.
Apart from this summing byte is not more than value form the diagram
measures which comes into diagram measures that comes into action.
Question 3: (10 marks)
1. The unit taught details of BBR algorithm created by google and is
evaluated for the investigating the clog in TCP/IP protocol and
accelerating the conveyance of the information packet that are developed
for transmitting the information parcels via the web. The rate of
transmission of the frames in the network can be improvised with
calculating the round trip time required for sending and receiving the data
parcel from the source address to the destination address.
1
2. Diverse issues are recognized utilizing the BBR calculation, for example,
in case of “long haul links” it utilizes different item switch for controlling
the clog and it causes strange throughput. This is because of the
abatement in multiplicative and eruption. The data packets are optimized
for sending the packet and the jitter and loss of data packet are needed to
be controlled for increasing the efficiency of the network. The full
utilization of the bandwidth is used for controlling the blockage and
handling the errors in the network channel. If a bottleneck condition is
raised in the network it should be eliminated with the implementation of
“deep buffer” and “shallow buffer” The buffers are loaded using the
destination location and is adds an extra delay in the network.
2
3. Google built up its BBR calculation to accelerate the Transmission
control convention with optimizing the rate of sending and accepting the
information movement in the system and maintaining a control on the
congestion for avoiding blockage of the current route. The present TCP
clog control utilizes distinctive buffers for implementing a control on the
information movement stream on the system and limits the quantity of
unacknowledged packets. A slow start methodology is followed in the
present TCP control for expanding the blockage control window after
introduction of the association. Google uses the BBR algorithm for the
finding the best path and controlling the current speed of the network and
handling the exception condition in the TCP protocol for increasing its
efficiency.
3
4. The article of network world has been analysed for analysing various
kinds of issues which are present in TCP clog along with BPR convention
and acknowledgement in worldwide standard. Presence of TCP clog
4

COIT20261 Network Routing and Switching (Term 1, 2018)
Assignment item —Written Assessment-2
controls for effective utilization and is mainly connected in various kinds
of convention. BPR calculation is mainly used for application and
supplanting in presence of TCP demonstration. BRP calculation is not
considered to be perfect for various kinds of system administration in
such a way that it can be utilized in good systems.
Total marks awarded 25 (max)
Less late penalties if applicable
Less plagiarism penalties if applicable
Total marks earned
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