Solved–Assignment 4: Network Simulation Using ns-3 –Solution

Description

Table 1: Allocation of applications to groups

Application Number Group Numbers

1 1, 7, 13, 19, 25, 31, 37, 43

2 2, 8, 14, 20, 26, 32, 38, 44

3 3, 9, 15, 21, 27, 33, 39, 45

4 4, 10, 16, 22, 28, 34, 40, 46

5 5, 11, 17, 23, 29, 35, 41, 47

6 6, 12 ,18 ,24 ,30 ,36 ,42 ,48

1

Application #1:

Analyse and compare TCP Hybla, TCP Westwood+, and TCP YeAH-TCP performance. Select a Dumbbell topology with two routers R1 and R2 connected by a (10 Mbps, 50 ms) wired link. Each of the routers is connected to 3 hosts, i.e. H1, H2, H3 (i.e. senders) are connected to R1, and H4, H5, H6 (i.e. receivers) are connected to R2. The hosts are attached with (100 Mbps, 20 ms) links. Both the routers use drop-tail queues with queue size set according to bandwidth-delay product. Senders (i.e. H1, H2 and H3) are attached with TCP Hybla, TCP Westwood+, and TCP YeAH-TCP agents, respectively. Choose a packet size of 1.5 KB and perform the following tasks. Make appropriate assumptions wherever necessary.

1. Start only one flow and analyse the throughput over sufficiently long duration. Mention how you select the duration. Plot the evolution of congestion window w.r.t. time. Perform this experiment with all the flows attached to all the three sending agents.

2. In the next experiment, start 2 other flows sharing the bottleneck link while the first one is in progress and measure the throughput (in Kbps) of each flow. Plot the throughput and evolution of the TCP congestion window for each of the flow at a steady-state. Report the maximum throughput observed for each of the flows.

3. Measure the congestion loss and the goodput over the duration of the experiment for each of the flows.

2
Application #2:

Compare the performance of TCP over wired and wireless networks. Consider a topology as described below. The network consists of two TCP sources Node0 and Node2, corresponding to two TCP destinations Node1 and Node3 respectively. Node2 and Node3 come in wired domain with two routers R1 and R2 (connected by a {10 Mbps, 50 ms} wired link) between them. Both the routers use drop-tail queues with queue size set according to bandwidth-delay product. Node0 comes in domain of Base Station 1 (BS1) and Node1 comes in domain of Base Station 2 (BS2). BS1 and BS2 are connected by a (10 Mbps, 100 ms) wired link. The hosts, i.e. Node0, Node1, Node2, Node3 are attached with (100 Mbps, 20ms) links to routers or base stations (as shown in the figure below). The sources (Node0 and Node2)) use three TCP agents (i.e. TCP Westwood, TCP Veno and TCP Vegas) to generate three different TCP flows. Study and plot the fairness index (Jain’s fairness index) and throughput change when the TCP packet size is varied; all the other parameter values are kept constant. You should use the following TCP packet size values (in Bytes): 40, 44, 48, 52, 60, 250, 300, 552, 576, 628, 1420 and 1500 for your experiments. The throughput (in Kbps) and fairness index must be calculated at steady-state. Make appropriate assumptions wherever necessary.

3
Application #3:

Create a topology of two nodes N0 and N1 connected by a link of bandwidth 1 Mbps and link delay 10 ms. Use a drop-tail queue at the link. Set the queue size according to bandwidth-delay product. Create a TCP agent (type of the agent specified below) and FTP traffic at N0 destined for N1. Create 5 CBR traffic agents of rate 250 Kbps each at N0 destined for N1. Make appropriate assumptions wherever necessary. The timing of the flows are as follows:

FTP starts at 0 sec and continues till the end of simulation. CBR1 starts at 200 ms and continues till end.

CBR2 starts at 400 ms and continues till end. CBR3 starts at 600 ms and stops at 1200 ms. CBR4 starts at 800 ms and stops at 1400 ms.

CBR5 starts at 1000 ms and stops at 1600 ms. Simulation runs for 1800 ms.

1. Plot graph(s) of TCP congestion window w.r.t. time for following 5 TCP congestion control algorithm implementations, and describe the TCP congestion control algorithms’ behaviour.

Case 1: use TCP New Reno

Case 2: use TCP Hybla

Case 3: use TCP Westwood

Case 4: use TCP Scalable

Case 5: use TCP Vegas

2. Draw a graph showing cumulative TCP packets dropped w.r.t. time comparing above 5 TCP congestion control algorithm implementations.

3. Draw a graph showing cumulative bytes transferred w.r.t. time comparing above 5 TCP congestion control algorithm implementations.

4
Application #4:

Compare the effect of buffer size on TCP and UDP flows. Select a Dumbbell topology with two routers R1 and R2 connected by a (10 Mbps, 100 ms) link. Each of the routers is connected to 3 hosts, i.e. H1, H2, H3 are connected to R1, and H4, H5, H6 are connected to R2. All the hosts are attached to the routers with (100 Mbps, 10 ms) links. Both the routers (i.e. R1 and R2) use drop-tail queues with equal queue size set according to bandwidth-delay product. Choose a packet size of 1.5 KB. Start 3 TCP New Reno flows, and after a while start 3 CBR over UDP flows each with 20 Mbps. These flows are randomly distributed across H1, H2 and H3. Increase the rate of one UDP flow up to 100 Mbps and observe its impact on the throughput of the TCP flows and the other UDP flow. Vary the buffer size in the range of 10 packets to 800 packets and repeat the above experiments to find out the impact of buffer size on the fair share of bandwidth and plot the necessary graphs. Make appropriate assumptions wherever necessary.

5
Application #5:

Using the network simulator ns-3, study the characteristics of IEEE 802.11. For the purpose of experiment, use the topology as follows. There are 3 nodes in the network located in a straight line at locations 200*i, with i=0, 1, 2. Node 0 and Node 2 both have TCP traffic to Node 1 (started randomly within 1 to 5 seconds of starting the simulation). Consider TCP Westwood+ or TCP Hybla for the TCP agents at Node 0 and Node 2, respectively. You have to run the simulations and measure the following from the trace output (the averages are taken over all the nodes). Do not use PCAP file for collecting the trace. Use Flow Monitor module in ns-3 for trace collection. No marks will be given if you consider PCAP trace with Wireshark.

1. Average bandwidth spent in transmitting RTS, CTS, and ACK.

2. Average bandwidth spent in transmitting TCP segments and TCP acks.

3. Average bandwidth wasted due to collisions.

4. TCP throughput (number of acknowledged bytes per unit time) at each node.

You have to run the simulations for 50 seconds each with different RTS thresholds (i.e. 0, 256, 512 and 1024 bytes) and TCP segment size of 1000 bytes. You can use scripts for trace file analysis and to plot the results. Make appropriate assumptions wherever necessary.

0 1 2

6
Application #6:

The objective is to compare the effect of CBR traffic over UDP agent and FTP traffic over TCP agent. Consider a TCP agent from TCP HighSpeed, TCP Vegas and TCP Scalable for the FTP traffic. Consider a Dumbbell topology with two routers R1 and R2 connected by a wired link (30 Mbps, 100 ms), and use drop-tail queues with queue size set according to bandwidth-delay product of the link. Each of the routers is connected to 2 hosts, i.e. H1, H2 are connected to R1, and H3, H4 are connected to R2. The hosts are attached to the routers with (80 Mbps, 20ms) links. The CBR traffic over UDP agent and FTP traffic over TCP agent are attached to H1 and H2 respectively. Choose appropriate packet size for your experiments and perform the following:

1. Compare the delay (in sec) and throughput (in Kbps) of CBR and FTP traffic streams when only one of them is present in the network. Plot the graphs for the delay (in sec) and throughput (in Kbps) observed with different packet sizes.

2. Start both the flows at the same time and also at different times. Also, compare the delay (in sec) and throughput (in Kbps) of CBR and FTP traffic streams. Plot the graphs for the delay (in sec) and throughput (in Kbps) observed with different packet sizes.

Make appropriate assumptions wherever necessary.

7
Table 2: Group Members corresponding to each Group

Group ID Roll Name Application ID
Assigned

1 150123034 ROHIT KUMAR 1
1 170123014 BARISH BHAGAT 1
1 170123026 KONDRU SURAJ 1
1 170123006 ANKIT TRIPATHI 1
2 170101055 ROHAN NIGAM 2
2 170123036 MOHIT DHAKA 2
2 170123037 MOHIT KUMAR MEENA 2

3 170101005 AMAN MISHRA 3
3 170101031 KEERTI HARPAVAT 3
3 170101049 Priyanshu Singh 3
4 170101081 UDBHAV CHUGH 4
4 170123013 BAGAL SATEJ BABANRAO 4
4 170123052 TANYA CHAUHAN 4

5 170123015 BOJJA SAI PREETHAM 5
5 170123024 KESHETTI SAI KUMAR 5
5 170123031 MALISETTI KIRAN KARTHEEK 5
6 170101036 MANI MANNAMPALLI 6
6 170101068 SUNNY KUMAR 6
6 170101087 SIDDHARTH AGARWAL 6

7 170101084 MAYANK BARANWAL 1
7 170123017 DEV PRIYA GOEL 1
7 170123059 SHRUTI DINESH AGARWAL 1
8 170101035 MANAN GUPTA 2
8 170123011 ASHISH AGARWAL 2
8 170123038 MRIGANKA BASU ROY CHOWDHURY 2

9 170101043 PARTHA PRATIM MALAKAR 3
9 170101048 PRANSHU SRIVAS 3
9 170101070 THAHIR MAHMOOD POOVADA 3
10 170101039 NAGULAPALLI KASI VENKATA SAI KIRAN 4
10 170101051 RAJANALA HARSHAVARDHAN REDDY 4
10 170123016 CHINDAM SUJANA MAITHILI 4

11 170101029 KAPIL JANGID 5
11 170101044 PARVINDAR SINGH 5
11 170101057 RUTVIK GHUGHAL 5
12 170101077 VEMURI SAHITHYA 6
12 170123039 NAKKA LAHARI 6
12 170123054 TUMARADA ADITYA 6

13 170101054 RISHI PATHAK 1
13 170101063 SHIVAM BANSAL 1
13 170101088 SHASHANK SHARMA 1
14 170101040 NAKKA SRIHARSHA 2
14 170123025 KOMMINENI NIKHIL 2
14 170123028 KRISHNA PRIYATAM D 2
15 170101001 AAYUSH PATNI 3
15 170101052 RASHI SINGH 3
15 170101066 SOUMIK PAUL 3
16 170101033 LUCKY 4
16 170101034 MAKHARIA AAYUSH 4
16 170123021 HEMANT YADAV 4

8

Group ID Roll Name Application ID
Assigned

17 170123004 ADITYA RAJ 5
17 170123040 PARV SOOD 5
17 170123043 SAHILPREET SINGH THIND 5
18 160101011 AKHIL CHANDRA PANCHUMARTHI 6
18 170101017 CH ROHITH RAVI PRABHU TEJA 6
18 170101050 PULIKONDA ROOP SAI RAKESH GUPTA 6
19 170101006 AMAN RAJ 1
19 170123029 KUSHAGRA MAHAJAN 1
19 170123034 MIHIR YADAV 1
20 170101074 UMANG 2
20 170123051 TANVI OHRI 2
20 170123053 TEJASVEE PANWAR 2
21 170101078 VINEET MALIK 3
21 170101080 VIVEK KUMAR 3
21 170101085 Sparsh Sinha 3
22 170101019 CHIRAG GUPTA 4
22 170101076 VAKUL GUPTA 4
22 170101082 LAVISH GULATI 4
23 170101026 HARDIK KATYAL 5
23 170101030 KARTIK GUPTA 5
23 170101075 UTKARSH JAIN 5
24 170123023 KEDAR NATH 6
24 170123056 PRATHIK.S.NAYAK 6
24 170123064 AGNIV BANDYOPADHYAY 6
25 170101060 SANCHIT 1
25 170123018 GARVIT MEHTA 1
25 170123020 harit gupta 1
26 170101002 ABHISHEK JAISWAL 2
26 170101038 MAYANK WADHWANI 2
26 170123007 ANKUR PRAMOD INGALE 2
27 170101067 SOURABH JANGID 3
27 170101071 THEEGALA RAKESH REDDY 3
27 170101073 TUSHAR RAJENDRA BHUTADA 3
28 170101009 ANUBHAV TYAGI 4
28 170101045 Piyush Gupta 4
28 170101053 RAVI SHANKAR 4
29 160101017 AUTONU KRO 5
29 170101023 FUGARE ASHISH DILEEP 5
29 170101027 KADAM KIRAN ZATINGRAO 5
30 170101011 ARANYA ARYAMAN 6
30 170101015 AVNEET SINGH CHANNA 6
30 170101041 NAVEEN KUMAR GUPTA 6

31 170101059 Sachin Giri 1
31 170101061 SAYAK DUTTA 1
31 170123010 ARYAN RAJ 1
32 170101013 ARYAN AGRAWAL 2
32 170101014 AVIRAL GUPTA 2
32 170101022 DEVANSH GUPTA 2

9

Group ID Roll Name Application ID
Assigned

33 170101064 SHUBHAM KUMAR 3
33 170101065 SHYAM SUNDAR RAV 3
33 170101079 VINIT KUMAR 3
34 170101037 MAYANK CHANDRA 4
34 170101046 PRABHAT KUMAR 4
34 170123050 SUMEDH RAVI JOURAS 4

35 170123001 AAYUSH BANSAL 5
35 170123057 KARTIK SETHI 5
35 170123058 ARUN KUMAR 5
36 170101008 ANNANYA PRATAP SINGH CHAUHAN 6
36 170101012 ARPIT GUPTA 6
36 170101086 SHIVANG DALAL 6

37 170123027 KOTTA PREM SUJAN 1
37 170123035 MOGILLAPALLI NIKHIL 1
37 170123042 S SAI VAMSHI 1
38 170101007 ANIKET RAJPUT 2
38 170101020 DEEPAK GAMI 2
38 170101047 PRANAY GARG 2

39 170101056 ROUNAK PARIHAR 3
39 170101058 RYTHUM SINGLA 3
39 170101083 UTKARSH SANTOSH MISHRA 3
40 170123060 TRIKAY NALAMADA 4
40 170123061 MAHFOOZUR RAHMAN KHAN 4
40 170123062 DIVYANSH MANGAL 4

41 170123003 ABHINAV R 5
41 170123008 ARAV GARG 5
41 170123063 JOEL RAJA SINGH 5
42 170101021 DEVAISHI TIWARI 6
42 170123048 SIDDHANT SINHA 6
42 170123022 JAYANT PATIDAR 6

43 170123012 AYUSH DALIA 1
43 170123033 MAYANK SAHARAN 1
43 170123044 SAKSHI SHARMA 1
44 170123002 ABHINAV ANAND 2
44 170123041 RUPAM SAHU 2
44 170123045 SAURABH KUMAR 2

45 170123019 GARVIT SARJARE 3
45 170123032 MANNE HEMA PRIYA 3
45 170123046 SHALINI KUMARI 3
46 170101004 AJINKYA SHIVASHANKAR SHIVASHANKAR 4
46 170101025 HANSRAJ PATEL 4
46 170101003 ADITYA VARDHAN GARA 4

47 170101016 BANDAGONDA SHRI RAAM REDDY 5
47 170101018 CHALUMURU BHAVANI DATT 5
47 170101024 GEDDAM IKYA VENUS 5
47 160101074 Sumedh Manwar 5
48 170101028 KANCHUGANTLA RHYTHM 6
48 170101032 KETHAVATH NAVEEN 6
48 170101042 NAYANJYOTI DEURY 6
49 170123005 ANKIT KUMAR KANOJIYA 6

10