COIT20261 Network Routing and Switching Term 2, 2019

COIT20261 Network Routing and Switching Term 2, 2019
Assignment item —Written Assessment-2
ANSWER TEMPLATE ASSIGNMENT TWO
Type your answers in the spaces provided
Marking criteria: Your answers will be marked based on technical correctness,
completeness, clarity, originality and relevance. Proper use of referencing conventions
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expressed in your own words. An answer is unacceptable if it is composed mostly of
quoted material from other sources and may in some cases receive no marks as a result.
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Questions Mark
allocated
Mark
earned
Question 1: (10 marks) 5 each
table
Answer: Routing table of router R1:
Mask Network address Next-hop address Interface
255.255.0.0 150.3.0.0 150.3.0.4 Loopback
255.255.255
.0
200.11.60.0 150.3.0.2 M0
255.255.252
.0
140.21.0.0 150.3.0.2 M0
255.255.192
.0
150.32.0.0 150.3.0.1 M0
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
Routing table of router R4:
Mask Network address Next-hop address Interface
255.255.0.0 150.3.0.0 150.3.0.1 Loopback
255.255.255
.0
200.11.60.0 150.3.0.2 M0
255.255.252 140.21.0.0 150.3.0.2 M0
5 max
5 max

COIT20261 Network Routing and Switching Term 2, 2019
Assignment item —Written Assessment-2
.0
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
255.255.192
.0
150.32.0.0 150.3.0.1 M0
Question 2: (5 marks)
a) The router is designed to route the data packet reaching to it with the
help of switching mechanism. Firstly the header of the received data
packet is de-encapsulated for exposing the third layer of the data
packets. The packet is examined for getting the destination IP and a
checking is done on routing table for getting the presence of IP address.
If the destination IP is present in the routing table it is forwarded to that
address and in case the address is not found the packet is sent to the next
hop router. The next hop router performs the same mechanism and this
process continues until the data packet is sent to its final destination IP.
During forwarding the data packet the third layer data packets are
encapsulated in layer 2 frame and sent to exit interface of router.
1 max
b) Packet arrives at R3 having destination address of 200.11.60.120 the
forwarding process of the router is given below:
The packet gets forwarded to interface labelled M0 and it reaches
the loopback address of 150.3.0.0/16 and from there it is forwarded
to router R2. The router determines the path for delivering packet
to IP 200.1160.120 and forwards it to the m1 interface havin
network address if 200.11.60.0/24 by estimating header index. The
outgoing interface is selected from the header index and the data
packet is forwarded to the destination node.
2 max
c) In case a packet having IP address as destination 150.32.203.10 arrives
at Router R3 an examination is made on the header index and such that
an outgoing interface is selected such that the data packet is forwarded.
The m0 interface is selected on finding the address of the header for
forwarding it to the next hop router. This step is continued until the
destination address is found for the data packet.
2 max
Question 3: (10 marks)
1) Congestion control that are used in TCP are achieved with the
application of different algorithm for increasing the efficiency of a
network. The throughput can be improved with the use of RENO and
1 max