Maharastra EXTC NetSim Experiment Manual

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Contents
ETC 702 MOBILE COMMUNICATION ........................................................... 6
Introduction to Wireless Communication.............................................. 61.
Orthogonal Frequency Division Multiple Access.................................... 62.
To study the working of Time Division Multiple Access technique ...... 123.
Study how call blocking probability varies as the load on a GSM4.
network is continuously increased............................................................... 15
GSM Network Architecture................................................................. 195.
Introduction to GSM frame structure.................................................. 196.
Protocol Architecture.......................................................................... 197.
Call Procedure..................................................................................... 198.
Handoff Procedure............................................................................. 199.
Analysis of GSM Handover.................................................................. 2010.
CDMA Network Architecture............................................................... 2411.
Forward and Reverse channel In CDMA ............................................. 2412.
Establishing a Connection In 3G System .............................................. 2413.

Handover in CDMA ............................................................................. 2414.
Study how the number of channels increases and the Call blocking15.
probability decreases as the Voice activity factor of a CDMA network is
decreased .................................................................................................... 25
To Study how the throughput of LTE network varies as the distance16.
between the ENB (Evolved node B) and UE (User Equipment) is increased .. 29
Study how the throughput of LTE network varies as the Channel17.
bandwidth changes in the ENB (Evolved node B) ......................................... 35
Analysis of LTE Handover .................................................................... 4118.
Study how the Data Rate of a Wireless LAN (IEEE 802.11b) network19.
varies as changing Wireless Channel Characteristics ................................... 46
ETC 801 WIRELESS NETWORK .................................................................... 52
Introduction to GSM ........................................................................... 5220.
Analyze the scenario shown, where Node 1 transmits data to Node 2,21.
with no path loss and obtain the theoretical throughput based on IEEE
802.15.4 standard. Compare this with the simulation result. ....................... 52
Mobility Models in Wi-MAX (IEEE 802.16e/m) Network...................... 5822.
Study the SuperFrame Structure and analyze the effect of SuperFrame23.
order on throughput.................................................................................... 63
ETC 803 INTERNET AND VOICE COMMUNICATION........................................ 68
TCP/IP Networking model................................................................... 6824.

Internet Layering and ISO Model......................................................... 6825.
Understand IP forwarding within a LAN and across a router ............... 6826.
Dynamic Host Configuration Protocol ................................................. 7527.
Configure and analyze the TCP versus UDP response Time With HTTP28.
Application .................................................................................................. 78

ETC 702 MOBILE COMMUNICATION
Introduction to Wireless Communication1.
Refer: Study theory from NetSim ”Basic Menu Internetwork Wireless LAN “
Orthogonal Frequency Division Multiple2.
Access
Programming Guidelines
This section guides the user to link his/her own code for Orthogonal Frequency Division
Multiple Access to NetSim.
Pre-conditions
The user program should read the input scenario from text file named „Input‟ with extension
txt which is in Temporary Directory.
The user program after executing the concept should write the required output to a file named
„Output’ with extension txt in Temporary Directory.
Note: The temporary directory is navigated through the following step.
Run Type "%temp%"  NetSim  "Input.txt" and "Output.txt"
( Note: For Run Press Windows + R)
General Program Flow
The program begins with the Reading of the Inputs from the input file Input.txt.
Executing the required concept and, the results of the program should be written into the
output file Output.txt.

Input File Format Output File Format
The following lines will be
in Input.txt file.
Number of users = Value
User1 =Value
User2 =Value
User3 =Value
User4 =Value
Number of sub carrier per
user = Value
Example:
Number of users = 4
User1 =111111111111
User2 =010101010101
User3 =101010101010
User4 =000000000000
Number of sub carrier per
user = 4
Parallel Data Conversion
User 1
Value
User 2
Value
User 3
Value
User 4
Value
Bit Mapping
User 1
Value
User 2
Value
User 3
Value
User 4
Value
SubCarrier Mapping
User 1
Value
User 2
-Value
User 3
Value
User 4
Value
SubCarrier Addition
User 1

Value
User 2
Value
User 3
Value
User 4
Value
Example:
Parallel Data Conversion
User 1
1 1 1 1
1 1 1 1
1 1 1 1
User 2
0 1 0 1
0 1 0 1
0 1 0 1
User 3
1 0 1 0
1 0 1 0
1 0 1 0
User 4
0 0 0 0
0 0 0 0
0 0 0 0
Bit Mapping
User 1
1 1 1 1
1 1 1 1
1 1 1 1
User 2

-1 1 -1 1
-1 1 -1 1
-1 1 -1 1
User 3
1 -1 1 -1
1 -1 1 -1
1 -1 1 -1
User 4
-1 -1 -1 -1
-1 -1 -1 -1
-1 -1 -1 -1
SubCarrier Mapping
User 1
sin(2PIf0t) sin(2PIf1t) sin(2PIf2t) sin(2PIf3t)
User 2
-sin(2PIf4t) sin(2PIf5t) -sin(2PIf6t) sin(2PIf7t)
User 3
sin(2PIf8t) -sin(2PIf9t) sin(2PIf10t) -sin(2PIf11t)
User 4
-sin(2PIf12t) -sin(2PIf13t) -sin(2PIf14t) -sin(2PIf15t)
SubCarrier Addition
User 1
sin 2PI(f0+f1+f2+f3)t

User 2
sin 2PI(-f4+f5-f6+f7)t
User 3
sin 2PI(f8-f9+f10-f11)t
User 4
sin 2PI(-f12-f13-f14-f15)t
sin 2PI(-f12-f13-f14-f15)t
sin 2PI(-f12-f13-f14-f15)t
Interface Source Code
Interface Source code written in C is given. Using this, the user can write only the
fnOFDMA() and fnSubcarrierAddition() functions, using the variables already declared.To
view the interface source code, go to
NetSim Installation path/src/Programming/OFDMA.c
To find NetSim‟s Installation path right click NetSim icon and select
 Open file location in Windows 7
 Open file location in Windows Vista
 Properties  find target in Windows XP.
Sample Scenarios:
Objective - To study the working of Orthogonal Frequency Division Multiple Access
technique
How to Proceed? - The objective can be executed in NetSim using the programming
exercise available. Under programming select Multiple Access Technology OFDMA

Sample Inputs - In the Input panel,
 Sample Mode should be selected.
 The value of Number of Users needs to be selected.
 Enter the Binary Datafor each user.
 Number of SubCarriers per User needs to be selected.
 Then Run button needs to be clicked. Refresh button can be used if new Inputs have to
be given.
Output - The following steps are done internally by NetSim
 The values of each userBinary Data, Parallel Conversion, Bit Mapping, SubCarrier
Mapping&SubCarrier Addition and Transmission will be shown in the right hand
side of the screen by animation.
 Once the sample experiment is done Refresh button can be clicked to create new
samples.

To study the working of Time Division Multiple3.
Access technique
3.1 How to Proceed:
The objective can be executed in NetSim using the programming exercise available, under programming
user has to select Multiple Access Technology  Time Division Multiple Access.
3.2 Sample Inputs:
In the Input panel the following steps need to be done,
 Sample Mode should be selected.
 Enter the Value of the Bandwidth.
 Enter the Value of the No. of Time Slots.
 Enter the Value of the TimeSlotLength.
 Enter the Value of the GuardInterval
Note: The Values entered should be within the range.
Bandwidth(kHz) 200
No. of TimeSlots 3
TimeSlotLength(µs) 100
GuardInterval(µs) 10
 Then Run button need to be clicked. Refresh button can be used, if new
Inputs have to be given.

3.3 Output:
The Output for the above sample is as follows,
 Bandwidth is divided into Time slots called channel.
 The first channel is allocated to first mobile station, second channel is
allocated to second mobile station and so on.
 The first Mobile Station will access the medium in first channel time slot.
 The Second Mobile Station will access the medium in second channel
time slot, and so on.
 During the guard interval, No mobile station will access the medium. This
is used to avoid the collision or interference.
Finally the table will be showed as follows,
 Channel no. is obtained.
 Bandwidth value is obtained.
 Start Time and End Time of the Guard Interval is obtained
 Start Time and End Time of the channel is obtained.
 Which Mobile Station is accessing the allocated time slot is obtained.
Channel number Bandwidth(kHz) Time(µs) Mobile Station
0 200 0.0 – 5.0 0
1 200 5.0 – 95.0 1
0 200 95.0 – 100.0 0
0 200 100.0 – 105.0 0
2 200 105.0 – 195.0 2
0 200 195.0 – 200.0 0
0 200 200.0 – 205.0 0
3 200 205.0 – 295.0 3
0 200 295.0 – 300.0 0

0 200 300.0 – 305.0 0
1 200 305.0 – 395.0 1

Study how call blocking probability varies as the load on a4.
GSM network is continuously increased.
4.1 Procedure:
In NetSim, Select “Simulation  New  Cellular Networks  GSM”
Follow the steps given in the different samples to arrive at the objective.
In this Experiment,
 One BTS (BTS A) and one MSC (MSC B) is used
 Total no of MS used: Vary from 4 to 20 in steps of 2.
The devices are inter connected as given below,
 All the MS are placed in the range of BTS A
Set the properties by following the tables for each sample,
Inputs for Sample 1
Number of MS = 4

Accept default properties for BTS.
Edit Uplink Bandwidth Min to 890 MHz and Uplink Bandwidth Max to 890.2 MHz in
MSC properties.
In the Sample 1, two Applications are run. After dropping Application on the Environment
menu, add application 2 from the left pane and change the following properties:
Application Properties Application 1 Application2
Application type Erlang_call Erlang_call
Source_Id 3 5
Destination_Id 4 6
Call
Duration_ Distribution Exponential Exponential
Duration(s) 60 60
Inter Arrival Time (sec) 10 10
IAT_ Distribution Exponential Exponential
Codec
Codec Custom Custom
Service Type CBR CBR
Packet Size 33 33
Inter Arrival Time (µs) 20000 20000

0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1 2 3 4 5 6 7 8 9
CallBlockingProbability
Sample Number
Simulation Time – 100 sec
Inputs for Sample 2
Number of MS = 6
Add one more Application and set the properties as above with Source_Id as 7 and
Destination_Id as 8.
Likewise, increase the number of MS by 2 upto 20 and set properties for different Samples
by adding an application every time and changing Source_Id and Destination_Id.
4.1.1 Output
To view the output, go to the Cellular Metrics.
In MS metrics, add the call blocked and call generated column. Call blocking probability is
calculated as ratio of Total call blocked to Total call generated.
Comparison Charts
*** All the above plots highly depend upon the placement of Mobile station in the simulation
environment. So, note that even if the placement is slightly different the same set of values
will not be got but one would notice a similar trend.

4.1.2 Inference:
When the number of MS is increased from 4 to 20 the call blocking probability increases
from 0 to 0.88. As we increase the number of mobile stations more calls are generated. This
increases the traffic load on the system & more calls generated implies more channel requests
arrive at the base station but the number of channels is fixed. So when the base station does
not find any free channel the call is blocked.
An additional observation is that the call blocking is zero until 8 MS. This is because the
number of channels is sufficient to handle all call that 6 MS may generate. Only after this the
base station does not find free channels and blocks calls.

GSM Network Architecture5.
Refer: Study theory from NetSim “Basic Menu Cellular Network  GSM 
Architecture “
Introduction to GSM frame structure6.
Frame Structure “
Protocol Architecture7.
Refer: Study theory from NetSim” Basic Menu Cellular Network  GSM 
Protocols”
Call Procedure8.
Refer: Study theory from NetSim” Basic Menu Cellular Network  GSM  Call
Flow “
Handoff Procedure9.
Handover “

Analysis of GSM Handover10.
10.1 Theory
GSM (Global System for Mobile communications) is an open, digital cellular technology
used for transmitting mobile voice and data services.
10.2 Procedure
Step 1:
In NetSim, Select “Simulation New Cellular
Networks GSM
Step 2:
Click & drop 2 Base Station ,1 MSC and 2 Mobile
Station on the Simulation Environment as shown and
link them.
Step 3:
 Arrange the positions of the Base Station as per the following table:
Base Station X-Coordinate Y-Coordinate
2 1000 1000
3 2000 1000

 Arrange the positions of Mobile Station as per the following table:
Mobile Station X-Coordinate Y-Coordinate
4 500 1000
5 1500 1000
Step 4:
Mobile Station Properties: Right click on the Mobile Station and set Velocity 1 m/s for
Mobile Station 4 and 100m/s for Mobile Station 5
Application Properties
Application Type ERLANG_CALL
Source_Id 4(Mobile Station D)
Destination_Id 5(Mobile Station E)
Call
Call Duration 1000 Sec
Inter Arrival Time 1 Sec

Step 4:
Simulation Time - 250 sec
(Note: The Simulation Time can be selected only after doing the following two tasks,
 Set the properties of Mobile Station
 Then click on Run Simulation button).
10.3 Output
Open Packet Animation:
Due to Mobility Mobile Stations can move from one cell to another. In the below figure,
users can see the handover packet flow in packet animation

 As shown in the above packet animation, MS D connected to BTS B and MS E
connected to BTS C
 MS E is moving from BTS C to BTS B due to mobility Which Causes Handover
 Then MS E Sends GSM_Channel_Request_For_Handover to BTS B
 In Response, The BTS B checks for resource availability and sends a
GSM_Channel_Granted to the MS E
10.4 Inference
Firstly MS E is communicating with BTS C. Due to mobility MS E moves from one cell to
another. So Handover occurs. Now MS E starts communicating with BTS B.

CDMA Network Architecture11.
Refer: Study theory from NetSim “Basic Menu Cellular Network CDMA
Architecture “
Forward and Reverse channel In CDMA12.
Refer: Study theory from NetSim” Basic Menu Cellular Network CDMA
Channels”
Establishing a Connection In 3G System13.
Refer: Study theory from NetSim ” Basic Menu Cellular Network  CDMA
Call flow diagram”
Handover in CDMA14.
Refer: Study theory from NetSim “Basic Menu Cellular Network CDMA
Handover”

Study how the number of channels increases15.
and the Call blocking probability decreases as
the Voice activity factor of a CDMA network is
decreased
15.1 Procedure:
How to Create Scenario & Generate Traffic:
In NetSim, Select “Simulation  New  Cellular Networks  CDMA”
Please navigate through the below given path to understand,
Inputs
In all Samples,
 Total no of BTS used: 1
 Total no of MSC used: 1
 Total no of MS used: 60
The devices are interconnected as given below,
 All the MS are placed in the range of BTS A ( default 1 Km)
 BTS A is connected via Wired Link to MSC B
Sample 1: Drop 1 BTS, 1 MSC and 60 MS and interconnect them in no specific order.

Application
Properties
Application
1
Application
2
Application
3
Application
4
Application
5
Source_Id 3 5 7 9 11
Destination_Id 4 6 8 10 12
All other
Properties
Default Default Default Default Default
Likewise add 25 more applications (totaling 30) with above properties and Source_Id13 to
Destination_Id 14 for application 6… and Source_Id 61 to Destination_Id 62 for application
30.
We have considered MSC to be device ID 1, and BTS as device ID 2.
Set Packet Animation to Don’t play/record animation (Simulation will run fast) and click
OK. If record animation option is selected, the simulation may take a long time to complete.
Upon completion of the experiment “Save” the experiment
Sample 2:
Keep all properties same as Sample 1 and in the BTS properties, change the voice activity
factor to 0.9 as shown:

Sample 3 and so on: Change the voice activity factor to 0.8 in sample 3, 0.7 in sample 4….
and to 0.1 in sample 10 in BTS properties.
15.2 Output
To view the output, go to the Cellular Metrics.
In Channel metrics, the channel count is mentioned.
For every sample plot the graph.
Comparison Charts and Inference:
0
50
100
150
200
250
300
350
400
450
1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1
ChannelCount
Voice Activity Factor

When the system Voice activity factor decreases from 1.0 to 0.1, the number of channels
increases from 3 to 30.
In CDMA network, the number of channels is inversely proportional to the voice activity
factor.
Chart 1 is a mirrored form of graph. (This is because VAF is decreasing along +ve X)
In MS metrics, the call generated and call blocked is shown for each MS. Add all the calls
generated to obtain Total call generated, and add calls blocked for all MS Ids to obtain Total
call blocked.
Calculate call blocking probability as ratio of Total call blocked to Total call generated.
When voice activity factor is decreased the number of channels available increases. Thus the
system has more number of channels to handle the same number of calls (Note - Number of
MS is constant and their properties are same across all experiments. So, they generate
approximately same number of calls throughout). As the number of channels increase the
call blocking probability decreases.
x
y
1

0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1
CallBlockingProbability
Voice Activity Factor

To Study how the throughput of LTE network16.
varies as the distance between the ENB
(Evolved node B) and UE (User Equipment) is
increased
16.1 Theory:
LTE or Long Term Evolution, commonly known as 4G LTE, is a standard for wireless
communication of high-speed data for mobile phones and data terminals. It is based on the
GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed
using a different radio interface.
The path loss in LTE is the decay of the signal power dissipated due to radiation on the
wireless channels. Path loss may be due to many effects, such as free space loss, refraction,
diffraction, reflection, aperture-medium coupling loss, and absorption.
Received power (Pr) can be calculated as:
Case 1: When no path loss Received power is same as Transmitted power, i.e., Pr = Pt
Case 2: When Line of Sight is there, Received power Pr is
Pr = Pt + Gt + Gr + +
Where Gt and Gr are gains of transmitting and receiving antenna respectively. Here d is the
distance between transmitter and receiver, λ is the wavelength of the transmitted signal and
is reference distance at which channel gain becomes 1. n is path loss exponent and Pt is
transmitted power.

16.2 Procedure:
16.2.1 How to Create Scenario & Generate Traffic:
 Create Scenario: Please refer “Help NetSim User Manual F1 Section 3.10 LTE”.
16.2.2 Sample Inputs:
In this experiment, 1 Router, 1 Wired Node and 1 MME , 1 UE and 1 ENB is clicked and
dropped onto the Simulation environment from tool bar as shown below.
Sample 1:
These properties can be set only after devices are linked to each other as shown above.
Wired Node Properties:
Node Properties Wired Node A
Transport Layer Properties
TCP Disable
Router Properties: Default properties.
MME Properties: Default properties.
ENB Properties:
ENB Properties ENB 4
Global Properties
X_Coordinate 0
Y_Coordinate 0

UE Properties:
UE Properties UE D
Global Properties
X_Coordinate 50
Y_Coordinate 50
Velocity(m/s) 0
To run the simulation, drop the Application icon and change the following properties:
Application Type Custom
Source ID 1 (Wired Node A)
Destination ID 5 (UE D)
Packet Size
Distribution Constant
Value(Bytes) 1460
Inter Arrival Time
Value(µs) 165
Wired Link Properties:
Link Properties Wired Link 1 Wired Link 2 Wired Link 3
Uplink Speed (Mbps) 100 100 100
Downlink Speed (Mbps) 100 100 100
Uplink BER No Error No Error No Error
Downlink BER No Error No Error No Error

Wireless Link Properties:
Link Properties Wireless Link 4
Channel characteristics Line of Sight
Path loss Exponent(n) 4
Simulation Time – 10 Sec
(Note: The Simulation Time can be selected only after the following two tasks,
 Set the properties for the Wired Node, Router, MME, UE, Wired, Wireless Links and
Application.
 Click on Run Simulation).
Upon completion of the experiment “Save” the experiment and note down the Application
throughput which is available in Application metrics for each sample case.
Sample 2:
Change the following properties in UE and run the simulation for 10 seconds as above. All
other properties are default.
UE Properties:
UE Properties UE D
Global Properties
X_Coordinate 100
Y_Coordinate 100
Velocity(m/s) 0
From Sample 3 to Sample 9:
Change the UE property every time (for all samples) by varying the (x, y) coordinates values
as follows:

Change in UE Properties: (x, y)
Sample 3 (150,150)
Sample 4 (200,200)
Sample 5 (250,250)
Sample 6 (300,300)
Sample 7 (350,350)
Sample 8 (400,400)
Sample 9 (450,450)
And note down the throughput values from the Application metrics in each sample case.
16.2.3 Output:
Step 1: Distance calculation:
Calculate the Distance between ENB (x1, y1) and UE(x2, y2) as follows: √(x2-x1)2
+ (y2-y1)2
For example for Sample 1:
ENB (x1, y1) = (0, 0); UE(x2, y2) = (50, 50);
Distance = √ (50-0)2
+ (50-0)2
= √2 × 50 = 50√2 meters.
Step 2:
Open the Excel file and note down the distance between UE and ENB and throughput values
as shown in below table.
Sample nos.
Sample Number
Distance between UE and
ENB (meters)
Throughput (Mbps)
1 50√2 = 70.71 70.774960
2 100√2 = 140.42 70.204976
3 150√2 = 212.13 62.544064
4 200√2 = 282.84 50.447088
5 250√2 = 353.55 30.223168
6 300√2 = 424.26 19.603712
7 350√2 = 494.97 15.645360

8 400√2 = 565.68 8.642032
9 450√2 = 636.39 4.468768
16.2.4 Comparison Chart
To draw these graphs by using Excel “Insert Chart” option and then select chart type as
“Column Chart”.
16.2.5 Inference
As the distance increases between ENB and UE, throughput value is getting decreased. The
reason is if distance increases between the devices, the received signal power will be
decreased due to high path loss.
0
10
20
30
40
50
60
70
80
70.71 140.42 212.13 282.84 353.55 424.26 494.97 565.68 636.39
Throughput(Mbps)
Distance (Meters)

Study how the throughput of LTE network17.
varies as the Channel bandwidth changes in
the ENB (Evolved node B)
17.1 Theory:
LTE or Long Term Evolution, commonly known as 4G LTE, is a standard for wireless
communication of high-speed data for mobile phones and data terminals. It is based on the
GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed
using a different radio interface.
LTE supports flexible carrier bandwidths, from 1.4 MHz up to 20 MHz as well as both FDD
and TDD. LTE designed with a scalable carrier bandwidth from 1.4 MHz up to 20 MHz
which bandwidth is used depends on the frequency band and the amount of spectrum
available with a network operator.
17.2 Procedure:
 Create Scenario: Go to Simulation  New  LTE Networks.
Sample Inputs:
In this experiment, 1 Wired Node ,1 Router, 1 MME , 1 ENB and 3 UE are clicked and
dropped onto the Simulation environment from tool bar as shown.

Sample 1:
Note: These properties can be set only after devices are linked to each other as shown above.
Node Properties Wired Node A
TCP Disable
Router Properties: Default properties.
MME Properties: Default properties.
ENB Properties:
ENB Properties ENB D
Interface_LTE (Physical Layer)
Channel Bandwidth (MHz) 20
To run the simulation, drop the Application icon and change the following properties:
Application
Properties
Application
1
Application
2
Application
3
Application Type Custom Custom Custom
Source ID
1 (Wired
Node A)
1 (Wired
Node A)
1 (Wired
Node A)
Destination ID 5(UE E) 6(UE F) 7(UE G)
Packet Size
Distribution Constant Constant Constant
Value(Bytes) 1460 1460 1460
Inter Arrival Time
Value(µs) 146 146 146

UE Properties:
UE Properties UE E UE F UE G
Global Properties
Velocity(m/s) 0 0 0
Link Properties Wired Link 2 Wired Link 3 Wired Link 4
Uplink Speed (Mbps) 1000 1000 1000
Downlink Speed (Mbps) 1000 1000 1000
Uplink BER 0 0 0
Downlink BER 0 0 0
Link Properties Wireless Link 1
Channel characteristics No Path Loss
Simulation Time – 10 Sec
 Set the properties for the Wired Node, Router, MME, UE, Wired, Wireless Links and
Application.
 Click on Run Simulation).
Upon completion of the experiment “Save” the experiment and note down the Application
throughputs of all applications which is available in Application metrics for each sample
case.

Sample 2:
Change the following properties in ENB and run the simulation for 10 seconds as above. All
other properties are default.
ENB Properties ENB D
Interface_LTE (Physical Layer)
Channel Bandwidth (MHz) 15
From Sample 3 & Sample 4:
Change the ENB property, Channel Bandwidth to 10, 5, 3, 1.4 MHz (Refer below table)
Sample Channel Bandwidth(MHz)
3 10
4 5
And note down the throughput values from the Application metrics in each sample case.
17.3 Output:
Step 1: Add the sum of all throughput values in each sample case:
Example:
Sample 1: Application ID Throughput (mbps)
1 24.846864
2 24.848032
3 24.848032
Sum = 74.542928 mbps.
Same procedure for all other sample cases also.

0
20
40
60
80
20 15 10 5
Throughput(Mbps)
Channel Bandwidth(MHz)
Step 2: Open the Excel file and note down the sum of applications throughput values as
shown in below table.
Sample nos.
Sample Number
Channel
Bandwidth(MHz)
Throughput (Mbps)
1 20 74.542928
2 15 52.160544
3 10 34.766688
4 5 17.351808
Comparison Chart:
To draw these graphs by using Excel “Insert Chart” option and then select chart type as
“Line chart”.
17.4 Inference
The LTE solution provides spectrum flexibility with scalable transmission bandwidth
between 1.4 MHz and 20 MHz depending on the available spectrum for flexible radio
planning. The 20 MHz bandwidth can provide up to 150 Mbps downlink user data rate and
75 Mbps uplink peak data rate with 2×2 MIMO, and 300 Mbps with 4×4 MIMO.
As the channel bandwidth decreases the number of resource blocks also decreases. If more
resource blocks are available then more number of packets can be transmitted.

Maharastra EXTC NetSim Experiment Manual

Analysis of LTE Handover18.
18.1 Introduction
Handover is an important function that maintains seamless connectivity when transitioning
from one base station to another.
18.2 LTE Handover Call Flow Description
1. A data call is established between the UE, S-eNB (Source-eNB) and the network
elements. Data packets are transferred to/from the UE to/from the network in both
directions (Downlink as well as Uplink)
2. The network sends the MEASUREMENT CONTROL REQ message to the UE to set
the parameters to measure and set thresholds for those parameters. Its purpose is to
instruct the UE to send a measurement report to the network as soon as it detects the
thresholds.
3. The UE sends the MEASUREMENT REPORT to the S-eNB after it meets the
measurement report criteria communicated previously. The S-eNB makes the
decision to hand off the UE to a T-eNB (Target-eNB) using the handover algorithm;
each network operator could have its own handover algorithm.
4. The S-eNB issues the RESOURCE STATUS REQUEST message to determine the
load on T-eNB (this is optional). Based on the received RESOURCE STATUS
RESPONSE, the S-eNB can make the decision to proceed further in continuing the
handover procedure using the X2 interface.
5. The S-eNB issues a HANDOVER REQUEST message to the T-eNB passing
necessary information to prepare the handover at the target side
6. The T-eNB checks for resource availability and, if available, reserves the resources
and sends back the HANDOVER REQUEST ACKNOWLEDGE message including
a transparent container to be sent to the UE as an RRC message to perform the
handover.
7. The S-eNB generates the RRC (Radio resource control->used for signalling transfer)
message to perform the handover, i.e., RRC CONNECTION RECONFIGURATION

message including the mobility Control Information. The S-eNB performs the
necessary integrity protection and ciphering of the message and sends it to the UE.
8. The S-eNB starts forwarding the downlink data packets to the T-eNB for all the data
bearers (which are being established in the T-eNB during the HANDOVER REQ
message processing).
9. In the meantime, the UE tries to access the T-eNB cell using the non-contention-
based Random Access Procedure. If it succeeds in accessing the target cell, it sends
the RRC CONNECTION RECONFIGURATION COMPLETE to the T-eNB.
10. The T-eNB now requests the S-eNB to release the resources. With this, the handover
procedure is complete.
 Due to mobility UEs can move from one place to another
 As shown in the above image, User Equipment is moving from Source-eNB to the
Target-eNB
 Then UE sends the MEASUREMENT REPORT to the S-eNB
 The S-eNB issues a HANDOVER REQUEST message to the T-eNB
 The T-eNB checks for resource availability and, if available, reserves the resources
and sends back the HANDOVER REQUEST ACKNOWLEDGE message

18.3 Procedure
How to Create Scenario & Generate Traffic in NetSim:
Step 1: Go to Simulation -> New -> LTE
Step 2: Click & drop 2 eNB‟s, 1 MME and 4 UE‟s onto the Simulation Environment.
Connect the 2 eNB‟s with MME using Wired Link.
Right click on UE and select Properties. Change the Velocity to 100m/s in Global Properties
for all UE‟s
Accept default properties for eNB and MME

Step 3:
Application Properties:
To add application, drop the Application icon. Edit the Application properties as given in
table. All other properties are default.
Application Type CUSTOM
Source ID 5
Destination ID 6
Step 4:
Click on Run Simulation icon and set simulation time = 100s.
18.4 Output
Open Packet Animation:
Due to Mobility UEs can move from one cell to another. In the below figure, users can see
the handover packet flow in packet animation.

 As shown in the above packet animation , UE E, UE D connected to eNB A and UE
F, UE G connected to eNB B
 UE F is moving from eNB B to eNB A due to mobility
 Then UEs send the LTE_Measurement_Report to eNB A, eNB B
 The eNB B sends a LTE_Handover_Request message to the eNB A
 The eNB A checks for resource availability and sends a
LTE_Handover_Request_Ack message to the eNB B
18.5 Inference
Firstly UE F is communicating with eNB B. Due to mobility UE F moves from one cell to
another. So Handover occurs. Now UE F starts communicating with eNB A.

Study how the Data Rate of a Wireless LAN19.
(IEEE 802.11b) network varies as changing
Wireless Channel Characteristics .
19.1 Theory:
In most of the WLAN products on the market based on the IEEE 802.11b technology the
transmitter is designed as a Direct Sequence Spread Spectrum Phase Shift Keying (DSSS
PSK) modulator, which is capable of handling data rates of up to 11 Mbps. The system
implements various modulation modes for every transmission rate, which are Different
Binary Phase Shift Keying (DPSK) for 1 Mbps, Different Quaternary Phase Shift Keying
(DQPSK) for 2 Mbps and Complementary Code Keying (CCK) for 5.5 Mbps and 11 Mbps.
Large Scale Fading represents Receiver Signal Strength or path loss over a large area as a
function of distance. The statistics of large scale fading provides a way of computing
estimated signal power or path loss as a function of distance and modulation modes vary
depends on the Receiver Signal Strength.
19.2 Procedure:
Please navigate through the below given path to,
Go to Simulation  New  Internetworks
Sample Inputs:
In Sample 1,
 Total no of APs (Access Points) used: 1
 Total no of Wireless Nodes used: 1
 Total no of Routers used: 1
 Total no of Switches used: 1
 Total no of Wired Nodes used: 1

The AP, Wireless Nodes, Router, Switch and Wired Nodes are interconnected as shown:
Also edit the following properties of Wireless Node E:
Wireless Node E Properties
X/Lat 365
Y/Lon 150
Interface_Wireless properties
RTS Threshold(bytes) 2347
Retry Limit(DataLink_Layer) 7
Rate _Adaptation true
Edit all link properties as shown:
Wireless Link Properties
Channel Characteristics Fading only
Path Loss Exponent 2.5
Fading Figure 1.0
Wired Link Properties
Uplink Speed (Mbps) 100
Downlink Speed (Mbps) 100
Uplink BER 0
Downlink BER 0

Also edit the following properties of Wired Node A:
Wired Node A Properties
TCP Disabled
Set the properties of Access Point as follows:
Access Point Properties
X/Lat 350
Y/Lon 150
Interface_Wireless properties
Buffer Size(MB) 5
RTS Threshold(bytes) 2347
Retry Limit 7
Click and drop the Application, set properties and run the simulation.
Source_Id 1
Destination_Id 5
Packet Size
Value (bytes) 1460
Packet Inter Arrival Time
Value (micro secs) 900

Simulation Time - 10 Sec
 Set the properties for all the devices and links.
 Click on Run Simulation button.
Upon completion of the experiment, “Save” the metrics result for comparison . Save the
Experiment in any user defined location.
 Sample 2: Change Wireless Channel Characteristics
Channel Characteristics Fading and Shadowing
Fading Figure 1.0
Channel Characteristics Line of Sight
Channel Characteristics No Path Loss

0
1
2
3
4
5
6
No Path Loss Line of Sight Fading Only Fading and
Shadowing
Throughput
Channel Characteristics
19.3 Output:
Channel
Characteristics
No Path Loss Line of Sight Fading Only Fading and
Shadowing
Throughput
(Mbps)
5.64 5.56 5.10 3.59
Comparison Chart:
19.4 Inference
*** All the above plots highly depend upon the placement of nodes in the simulation
environment. So, note that even if the placement is slightly different, the same set of values
In 802.11b, four data rates, 1 Mbps, 2 Mbps, 5.5 Mbps, and 11 Mbps, are supported. The rate
is decided based on the received power and the errors in the channel. Note a higher data rate
does not necessarily yield a higher throughput since packets may get errored. Only when the
channel conditions are good, does a higher data rate give a higher throughput. In a realistic
WLAN environment, the channel condition can vary due to pathloss, fading, and shadowing.
In NetSim to accommodate different channel conditions, rate adaptation is commonly
employed. The rate adaptation algorithms dynamically adjusts the modulation mode

and data rate to optimize performance when channel condition changes. So, when
NetSim detects that the number of errors in the channels are high, it automatically drops
down to a lower rate.
In addition, one must note that WLAN involves ACK packets after data transmission.. These
additional packet transmission lead to reduced Application throughput of 5.5 Mbps (at 1 – 20
mts range) even though the PHY layer data rate is 11 Mbps.

ETC 801 WIRELESS NETWORK
Introduction to GSM20.
Refer: Study theory from NetSim Basic Menu “Cellular ”  GSM
Analyze the scenario shown, where Node 121.
transmits data to Node 2, with no path loss and
obtain the theoretical throughput based on
IEEE 802.15.4 standard. Compare this with the
simulation result.
21.1.1 Introduction:
IEEE Standard 802.15.4 defines the protocol and compatible interconnections for data
communication devices using low-data-rate, low-power, and low-complexity short-range
radio frequency (RF) transmissions in a wireless personal area network (WPAN). In Wireless
sensor network IEEE 802.15.4 standard is used in MAC and PHY layers.
IEEE 802.15.4 PHYs provide the capability to perform CCA in its CSMA-CA mechanism.
The PHYs require at least one of the following three CCA methods: Energy Detection over a
certain threshold, detection of a signal with IEEE 802.15.4 characteristics or a combination
of these methods.

21.1.2 Theory:
 A packet transmission begins with a random backoff (in number of slots, each slot of 20
duration) which is sampled uniformly from 0 to and followed by a
CCA.
 CCA failure starts a new backoff process with the backoff exponent raised by one, i.e., to
macminBE+1, provided it is lesser than the maximum backoff value given by
macmaxBE.
 Maximum number of successive CCA failures for the same packet is governed by
macMaxCSMABackoffs, exceeding which the packet is discarded at the MAC layer.
 A successful CCA is followed by the radio turnaround time and packet transmission.
 If the receiver successfully receives the packet i.e., without any collision or corruption
due to PHY layer noise, the receiver sends an ACK after the radio turnaround time.
 A failed packet reception causes no ACK generation.
 The transmitter infers that the packet has failed after waiting for macAckWaitDuration
and retransmits the packet for a maximum of aMaxFrameRetries times before discarding
it at the MAC layer.
Note: In NetSim the radio turnaround time after a CCA success is not considered.
21.1.3 Procedure
How to Create Scenario: In NetSim, Select “Simulation  New  ZigbeeNetworks”
Create the scenario as shown:

Set the properties as shown below:
Node Properties:
Node Properties Zigbee Node B
Global Properties
X_Coordinate 15
Y_Coordinate 20
Interface1_Zigbee : Data Link Layer
AckRequest Enable
MaximumFrameRetries 7
Node Properties Zigbee Node C
Global Properties
X_Coordinate 25
Y_Coordinate 20
AckRequest Enable
MaximumFrameRetries 7
PAN Coordinator Properties:
Sink Node Properties Values
Global Properties
X_Coordinate 20
Y_Coordinate 20
Beacon Mode Disable

Environment Properties:
Environment Properties Values
Click and drop Application and edit the following properties:
Source_Id 2 (Zigbee Node B)
Destination_Id 3 (Zigbee Node C)
Packet_Size
Value(Bytes) 70
Inter_Arrival_time
Value(micro sec) 4000
(Note: If the size of the packet size at the Physical layer is greater than 127 bytes, the packet
gets fragmented. Taking into account the various overheads added at different layers (which
are mentioned below), the packet size at the application layer should be less than 80 bytes.)
Simulation Time: 100 Sec
Throughput obtained from the simulation is100.408kbps (0.100408 Mbps)
Note: This throughput is obtained when the nodes are placed at the closest possible distance
from the PAN coordinator. As the distance is increased, the throughput would reduce.
Theoretical Analysis:
We have set the Application layer payload as 70 bytes in the Node1 properties and when the
packet reaches the physical layer various other headers gets added like

App layer Payload 70 bytes
Transport Layer Header 8 bytes
Network Layer Header (IP + DSR) 28 bytes
MAC Header 5 bytes
PHY Header 6 bytes
Packet Size 117 bytes
In simulation, by default NetSim uses Unslotted CSMA/CA and so a packet transmission
happens after random backoff, CCA and turn-around-time and is followed by turn-around-
time and ACK packet and each of them occupies specific time set by the IEEE 802.15.4
standard as per the timing diagram shown below.
From IEEE standard, each slot has 20 Symbols in it and each symbol takes 16µs for
transmission:
Symbol Time 16 µs
Slot Time 20 * 0.32 ms
Random Backoff Average 3.5 * 1.12 ms
CCA 0.4 * 0.l28 ms
3.5
Slots
0.6
Slots
0.6
Slots
0.6
Slots
0.4
Slots
CCA
Turn around
Time
Random
backoffAvg
[0, 7]
117 bytes
11.7 Slots
Packet Turn
around
Time
Ack
Source Node Destination
Node

Turn-around-Time 0.6 * 0.192 ms
Packet Transmission Time 11.7 * 3.744 ms
Turn-around-Time 0.6 * 0.192 ms
ACK Packet Time 0.6 * 0.192 ms
Total Time 17.4 * 5.568ms
21.1.4 Inference:
Throughput from theoretical analysis matches the results of NetSim‟s discrete event
simulation.
(Note: The slight difference in throughput is due to fact that the average of random numbers
generated for backoff need not be exactly 3.5 as the simulation is run for short time and also
in Network layer DSR protocol is running, so route setup process will take some time.)
As we go on increasing the simulation time, the throughput value obtained from simulation
approaches the theoretical value as can be seen from the table below:
Throughput from simulation 100.408 kbps
Throughput from analysis 100.574 kbps
Simulation Time (sec) Throughput (kbps)
10 99.680
50 100.486
100 100.408
200 100.486

Mobility Models in Wi-MAX (IEEE 802.16e/m)22.
Network
22.1 Theory:
Random walk: In this mobility model, a mobile node moves from its current location to a
new location by randomly choosing a direction and speed in which to travel. Each movement
in the Random Walk Mobility Model occurs in either a constant time interval „t „or a constant
traveled ‟ d „distance, at the end of which a new direction and speed are calculated.
Random way point: The Random Way Point Mobility Model includes pauses between
changes in direction and/or speed. A Mobile node begins by staying in one location for a
certain period of time (i.e pause). Once this time expires, the mobile node chooses a random
destination in the simulation area. The mobile node then travels toward the newly chosen
destination at the selected speed. Upon arrival, the mobile node pauses for a specified period
of time starting the process again.
22.2 Procedure:
Sample 1(Random Walk):
Step 1:
In NetSim, Select “Simulation New  Advanced Wireless Networks Wi-Max”.

Step 2:
Drop 1 Base Station and 2 Wi-Max Subscriber as shown below:
Step 3:
BS Properties BS A
Global Properties
X_Coordinate 200
Y_Coordinate 50
Step 4:
Subscriber Node Properties Subscriber Node B Subscriber Node C
Global Properties
X_Coordinate 150 250
Y_Coordinate 100 100

Subscriber Node Properties: Right click on the Subscriber Node and set the Mobility
Model as RANDOM_WALK and Velocity(m/s) as 10 in all the Subscriber Nodes.
Step 4: Select the Application Button and click on the gap between the Grid Environment
and the ribbon. Now right click on Application and select Properties as shown below:
Source ID 2 (Subscriber Node B)
Destination ID 3 (Subscriber Node C)
Packet Size
Value(Bytes) 1460
Inter Arrival Time
Value(µs) 2336

Step 5:
After completion of the experiment, “Save” the experiment for future analysis of results.
Sample 1.b:
Open Sample 1.a, Right click on the Subscriber Node and set the Mobility Model as
RANDOM_WALK and Velocity(m/s) as 30 in all the Subscriber Nodes.
Sample 1.c:
Open Sample 1.b, Right click on the Subscriber Node and set the Mobility Model as
Sample 1.d:
Open Sample 1.c, Right click on the Subscriber Node and set the Mobility Model as
Sample 2(Random Way Point):
Sample 2.a:
Open Sample 1a, Right click on the Subscriber Node and set the Mobility Model as
RANDOM_WAY_POINT and Velocity(m/s) as 10 in all the Subscriber Nodes.
The remaining properties are same as Sample 1a.
Sample 2.b:
Open Sample 2.a, Right click on the Subscriber Node and set the Mobility Model as
Sample 2.c:
Open Sample 2.b, Right click on the Subscriber Node and set the Mobility Model as

Sample 2.d:
Open Sample 2.c, Right click on the Subscriber Node and set the Mobility Model as
22.3 Output
Velocity
(m/s)
Random Walk Random Way Point
Throughput
(Mbps)
Delay
(Second)
Throughput
(Mbps)
Delay
(Second)
10
30
60
90
2.62
2.57
2.53
2.30
1.78
1.89
1.85
1.96
2.57
2.49
2.37
2.29
1.78
1.99
2.08
2.03
22.4 Inference
As the mobility model is changed (Random Walk  Random Waypoint) the throughput of
the network decreases because the relative change in location of the devices increases.
Throughput of Random Waypoint is less compared to Random walk as the relative velocity
among the nodes is zero only during pause time.
The packet delivery ratio decreases as collisions are higher for higher relative velocity
leading to lower number of packets successfully reaching the destination.

Study the SuperFrame Structure and analyze23.
the effect of SuperFrame order on throughput.
23.1 Introduction:
Beacon frame is one of the management frames in IEEE 802.15.4 based WSN and contains
all the information about the network.
A coordinator in a PAN can optionally bound its channel time using a SuperFrame structure
which is bound by beacon frames and can have an active portion and an inactive portion. The
coordinator enters a low-power (sleep) mode during the inactive portion.
The structure of this SuperFrame is described by the values of macBeaconOrder and
macSuperframeOrder. The MAC PIB attribute macBeaconOrder, describes the interval at
which the coordinator shall transmit its beacon frames. The value of macBeaconOrder, BO,
and the beacon interval, BI, are related as follows:
For 0 ≤ BO ≤ 14, BI = aBaseSuperframeDuration * 2BO
symbols.
If BO = 15, the coordinator shall not transmit beacon frames except when requested to do so,
such as on receipt of a beacon request command. The value of macSuperframeOrder, SO
shall be ignored if BO = 15. An example of a SuperFrame structure is shown in following
Figure.

Fig: An example of the Super Frame structure
Theoretical Analysis:
From the above SuperFrame structure,
If SuperFrame Order (SO) is same as Beacon Order (BO) then there will be no inactive
period and the entire SuperFrame can be used for packet transmissions.
If BO=10, SO=9 half of the SuperFrame is inactive and so only half of SuperFrame duration
is available for packet transmission. If BO=10, SO=8 then (3/4)th of the SuperFrame is
inactive and so nodes have only (1/4)th
of the SuperFrame time for transmitting packets and
so we expect throughput to approximately drop by half of the throughput obtained when
SO=9.
Percentage of inactive and active periods in SuperFrame for different SuperFrame Orders is
given below:
Beacon
Order (BO)
SuperFrame
Order (SO)
Active part
ofSuperFrame(%
)
Inactive part of
SuperFrame (%)
Throughput
estimated (%)
10 10 100 0 > 200% of T
10 9 50 50 Say T = 20.18
(Got from simulation)
10 8 25 75 50 % T
10 7 12.5 87.5 25 % T
10 6 6.25 93.75 12.5 % of T
10 5 3.125 96.875 6.25 % of T
10 4 1.5625 98.4375 3.12% of T
10 3 0.78125 99.21875 1.56 % of T

We expect throughput to vary in the active part of the SuperFrame as sensors can transmit a
packet only in the active portion.
Simulation:
In NetSim, Go to “Simulation  New  Wireless Sensor Networks”
In grid settings, enter side length as 100 m and select sensor placement strategy as Via click
& drop
Click & drop one Sensor Node, Sink Node and Agent onto the Simulation Environment:
Sensor Properties: Change the following property for Sensor.
Sensor Properties Values
Velocity(m/s) 0
Interface1_Zigbee: Sensor
Sensor Interval (ms) 3

Sink Node Properties: Change the following properties for PAN Coordinator.
Sink Node Properties Values
Interface1_Zigbee: Data link Layer
Beacon Mode Enable
Beacon Order 10
Super frame Order 10
Simulation Time -30 Sec.
 Set the properties of Node, PAN Coordinator & Environment.
 Click on Run Simulation and save the experiment)
Sample 2 and so on: Vary the Super Frame Order for every sample (SuperFrame order = 9
for sample 2, and…, 3 for sample 8).
The following are the throughputs obtained from simulation for different SuperFrame Orders.
SuperFrame
Order
Throughput
(Kbps)
10 40.00
9 20.23
8 10.08
7 5.04
6 2.50
5 1.24
4 0.60
3 0.28

Note: To obtain throughput from simulation, payload transmitted values will be obtained
from Network statistics and calculated using following formula:
Comparison Chart:
*** All the above plots highly depend upon the placement of Sensor in the simulation
environment. So, note that even if the placement is slightly different the same set of values
23.1.1 Inference:
From the comparison chart both the simulation and theoretical throughputs match except for
the case with no inactive period. A sensor will be idle if the last packet in its queue is
transmitted. If a packet is generated in inactive period then the packet has to wait in the
queue till the next SuperFrame so sensor has packets waiting in its queue and so it cannot be
idle in the next SuperFrame, but if there is no inactive period then there might be no packets
waiting in the queue and so sensor can be idle resulting in lesser throughput.
0
5
10
15
20
25
30
35
40
45
10 9 8 7 6 5 4 3
Throughput(kbps)
Superframe Order
Simulated
Theoritical

ETC 803 INTERNET AND VOICE COMMUNICATION
TCP/IP Networking model24.
Refer: Study theory from NetSim “Basic Menu Internetwork  TCPIntroduction”
Internet Layering and ISO Model25.
Refer: Study theory from NetSim “Basic Menu Introduction Network Architecture 
Layering and OSI Model”
Understand IP forwarding within a LAN and26.
across a router
Note: NetSim Standard Version is required to run this experiment
26.1.1 Theory:
Nodes in network need MAC Addresses in addition to IP address for communicating with
other nodes. In this experiment we will see how IP-forwarding is done when a node wants to
send data within a subnet and also when the destination node is outside the subnet.
26.2 Procedure
Step 1:
Step 2:
Click & drop Wired Nodes, Switches
and Router onto the Simulation Environment as shown
and link them.

Node properties: Disable TCP in all nodes in Transport layer as follows:
Step 3: Create the Sample as follows
Sample 1:
To run the simulation, drop the Application icon and set Application type CUSTOM and the
Source_Id and Destination_Id as 1 and 2 respectively
Enabling the packet trace:
 Click Packet Trace icon in the tool bar. This is used to log the packet details.
 Check “All the Attributes” button for Common Attributes, TCP and WLAN.
 And Click on Ok button. Once the simulation is completed, the file gets stored in the
location specified.

Step 4:
Simulation Time- 10 Seconds
Note: The Simulation Time can be selected only after doing the following two tasks,
 Set the properties of Nodes
 Then click on the Run Simulation icon:
After clicking on Run Simulation, edit IP and ARP Configuration tab by setting Static ARP
as Disable. Click on OK button to simulate.
26.3 Output - I
Open Packet Trace for performing Packet Trace analysis
 PACKET TRACE Analysis

26.4 Inference - I
Intra-LAN-IP-forwarding:
 ARP PROTOCOL- WORKING
A Brief Explanation:
NODE-1 broadcasts ARP_Request which is then broadcasted by SWITCH-4. NODE -2
sends the ARP_Reply to NODE-1 via SWITCH-4. After this step, data is transmitted from
NODE-1 to NODE-2. Notice the DESTINATION_ID column for ARP_Request type
packets.
Step 5: Follow all the steps till Step 2 and perform the following sample:
Sample 2:
To run the simulation, drop the Application icon and set the Source_Id and Destination_Id as
1 and 3 respectively.
Source Switch
ARP REQUEST
Destination
ARP Response
ARP REQUEST
ARP Response

 Give a file name and check “All the Attributes” button for Common Attributes, TCP
and WLAN.
 And Click on Ok button. Once the simulation is completed, the file gets stored in the
specified location.
Step 6:
Simulation Time- 10 Seconds
Note: The Simulation Time can be selected only after doing the following two tasks,
 Set the properties of Nodes
 Then click on the Run Simulation icon:
After clicking on Run Simulation, edit IP and ARP Configuration tab by setting Static ARP
as Disable. Click on OK button to simulate.

26.5 Output - II
 PACKET TRACE Analysis
Across-Router-IP-forwarding:
Data
Packet
ARP request for
Destination’s MAC
address
ARP
Response
Source
Default Gateway
ARP request for
Default Gateway’s
MAC address
ARP response for
Default Gateway’s
MAC address
Source
Default Gateway
Destination
STEP-1
STEP-2
Data Packet

26.6 Inference -II
NODE-1 transmits ARP_Request which is further broadcasted by SWITCH-4. ROUTER-6
sends ARP_Reply to NODE-1 which goes through SWITCH-4. Then NODE-1 starts to send
data to NODE-3.
If the router has the address of NODE-3 in its routing table, ARP protocol ends here and data
transfer starts that is PACKET_ID 1 is being sent from NODE-1 to NODE-3. In other case,
Router sends ARP_Request to appropriate subnet and after getting the MAC ADDRESS of
the NODE-3, it forwards the packet which it has received from NODE-1.
When a node has to send data to a node with known IP address but unknown MAC address,
it sends an ARP request. If destination is in same subnet as the source (found through subnet
mask) then it sends the ARP (broadcast ARP message) request. Otherwise it forwards it to
default gateway. Former case happens in case of intra-LAN communication. The destination
node sends an ARP response which is then forwarded by the switch to the initial node. Then
data transmission starts.
In latter case, a totally different approach is followed. Source sends the ARP request to the
default gateway and gets back the MAC address of default gateway. (If it knows which router
to send then it sends ARP request to the corresponding router and not to Default gateway)
When source sends data to default gateway (a router in this case), the router broadcasts ARP
request for the destined IP address in the appropriate subnet. On getting the ARP response
from destination, router then sends the data packet to destination node.
PART 2: - Changing default Gateway
Do Sample 2 in PART 1 with the difference that in the properties of NODE-1, change the
default gateway to some other value, for ex. “192.168.2.76” and click on Simulate button.
You will get error. Because NODE-1 will check the IP address of NODE-3 and then realize
that it isn‟t in the same subnet. So it will forward it to default gateway. Since the default
gateway‟s address doesn‟t exist in the network, error occurs.

Dynamic Host Configuration Protocol27.
This section guides the user to link his/her own code for Dynamic Host Configuration
Protocol to NetSim.
Pre - Conditions
The user program should read the input from text file named „Input‟ with extension txt.
„Output’ with extension txt.
Note: The temporary directory is navigated through the following step.
Executing the required concept and
The results of the program should be written into the output file Output.txt.
Number_of_Clients = 4
Start_Address = 192.168.0.105
End_Address = 192.168.0.109
Mask = 255.255.255.0
DHCP_DISCOVER>
Node1>Node2>
Node1>Node3>
Node1>Node4>
Node1>Server
DHCP_OFFER>
Server>Node1
DHCP_REQUEST>
Node1>Server
DHCP_ACK>
Server>192.168.0.105
DHCP_DISCOVER>
Node2>Node1>
Node2>Node3>
Node2>Node4>
Node2>Server

DHCP_OFFER>
Server>Node2
DHCP_REQUEST>
Node2>Server
DHCP_ACK>
Server>192.168.0.106
DHCP_DISCOVER>
Node3>Node1>
Node3>Node2>
Node3>Node4>
Node3>Server
DHCP_OFFER>
Server>Node3
DHCP_REQUEST>
Node3>Server
DHCP_ACK>
Server>192.168.0.107
DHCP_DISCOVER>
Node4>Node1>
Node4>Node2>
Node4>Node3>
Node4>Server
DHCP_OFFER>
Server>Node4
DHCP_REQUEST>
Node4>Server
DHCP_ACK>
Server>192.168.0.108
Interface Source code written in C is given using this the user can write only the Dynamic
Host Configuration Protocol inside the function fnDHCPServer() and fnDHCPClient() using
the variables already declared.
To view the interface source code, go to
NetSim Installation path / src / Programming / DHCP.c
 Open file location in Windows 7

 Open file location in Windows Vista
 Properties  find target in Windows XP.
Sample Scenarios:
Objective - Find the Shortest Path using Dynamic Host Configuration Protocol.
How to Proceed? - The objective can be executed in NetSim by using the programming
exercise available. In the Programming menu selectDynamic Host Configuration
Protocol.
Sample Input -Follow the below given steps,
 Select number of clients.
 Set the Start Address and the End Address
 Click on Run button to execute.
Output - The Output that is obtained is given below,

Configure and analyze the TCP versus UDP28.
response Time With HTTP Application
Note: NetSim Standard Version is required to run this experiment
28.1 Theory
TCP provides connection-oriented service at the transport layer, and UDP provides
connectionless service. As a result, a data exchange using TCP can take longer than the same
exchange using UDP. TCP implementations require that the TCP source and destination
perform a three-way handshake in order to set up the connection prior to sending data, and a
four-way handshake when tearing down the connection. In addition, all data must be
acknowledged by the destination when it is received. UDP sources, on the other hand, do not
set up connections and so save the overhead in terms of delay and bandwidth usage. UDP is
often used when small amounts of data must be sent, for example, when doing credit card
verification. If large amounts of data are sent, however, the extra TCP overhead may be
negligible in comparison to the entire transaction completion time
28.2 Part-A – TCP
Procedure: Sample 1
Step 1:
Step 2:
Click & drop 2 Wired Nodes and 1
Router on the Simulation Environment
as shown and link them.

Application Type HTTP
Source_Id 2(Wired Node D)
Destination_Id 3(Wired Node C)
Page Property
Page Count 10
Page Size (bytes) 1000
Inter Arrival Time
Value ( secs) 1
Step 3:
Enable Packet Trace in Ribbon
Step 4:
 Enable Packet Trace
 Click on Run Simulation button.
After completion of the experiment, “Save” the experiment for future analysis of results.
28.3 Part-B – UDP
Procedure: Sample 2:
Open Sample 1 and Disable TCP in Transport Layer in both Wired Nodes and
Router

 Enable Packet Trace
 Click on Run Simulation button)
28.4 Output:
Open Packet Trace from performance metrics window
Apply filter option from Excel sheet, filter PACKET TYPE column: Select only HTTP
TCP Packet Trace
TCP Response Time: 1000385.28 - 1000054.56 = 330.72
UDP Packet Trace
UDP Response Time: 1000321.12-1000000.96=320.16

Response Time
( micro. sec)
TCP 330.72
UDP 320.16
28.4.1 Inference:
Response time of TCP is greater than UDP. Since TCP performs three way handshake
mechanisms, for each packet it has to wait for an acknowledgement. But in case of UDP,
there is no acknowledgement. Hence compared to TCP, UDP has less Response

Simulation of different types of internet29.
traffic such as FTP, TELNET over a network
and analyzing the throughput
29.1 Theory:
FTP is File Transfer Protocol that transfers the files from source to destination. It is an
application layer protocol. The file transfer takes place over TCP.
TELNET is Terminal Network Protocol that is used to access the data in the remote machine.
It is also an Application layer protocol. It establishes connection to the remote machine over
TCP.
29.2 Procedure:
29.2.1 How to Create Scenario & Generate Traffic:
 Create Scenario: “Simulation  New  Internetworks”.
29.2.2 Sample Inputs:
FTP, Database, Voice, HTTP, Email, Peer to Peer and Video are the traffic types available as
options in NetSim. To model other applications the “Custom” option is available. TELNET
application has been modeled in NetSim by using custom traffic type. Packet Size and Packet
Inter Arrival Time for TELNET application is shown below:
Packet Size
Packet Size (Bytes) 1460
Packet Inter Arrival Time
Packet Inter Arrival Time (µs) 1500

Fig 1: The Network Scenario
In this experiment, 8 Wired Nodes and 3 Routers need to be clicked & dropped onto the
Simulation environment. Wired Nodes A, B and C are connected to Router I. Wired Nodes
E, F, G and H are connected to Router K. Wired Node D is connected to Router J. Router I
and Router K are connected to Router J. The network scenario is shown in above fig 1.
Then follow these steps:
Sample 1: FTP Application from Wired Node D to Wired Node E.
Sample 2: FTP Application from Wired Node D to Wired Node E. TELNET Application
from Wired Node A to Wired Node F.
from Wired Node A to Wired Node F. TELNET Application from Wired Node B to Wired
Node G.
TELNET
FTP

from Wired Node A to Wired Node F. TELNET Application from Wired Node B to Wired
Node G. TELNET Application from Wired Node C to Wired Node H.
Note: Select “custom” for “TELNET” application
Inputs for the Sample experiment are given below:
Set the following properties for all wired links.
Set the following properties for Wired Node D if application type is FTP and destination is
Wired Node E. Set the following properties for Wired Node A if application type is TELNET
and destination is Wired Node F.
Node Properties Wired Node D Wired Node A
TCP Enable Enable
Application Properties: (set the application property as per screenshot)
Application Type FTP Custom(for TELNET)
Source ID Wired Node D Wired Node A
Destination ID Wired Node E Wired Node F
Size
Distribution Constant Constant
Size (Bytes) 10000000 1460
Inter Arrival Time
Inter Arrival Time 10 sec 1500 (µs)
Router Properties: Accept default properties for the Router.

Wired Link Properties: Set the following properties for all Wired Links.
Link Properties All Wired Links
Uplink Speed (Mbps) 1
Downlink Speed (Mbps) 1
Uplink BER No Error
Downlink BER No Error
Upon completion of the experiment “Save” the experiments for comparisons which is carried
out in the “Analytics” section and export to .csv to save the results.
29.2.3 Output:
Open the Excel Sheet and note down the various throughputs as shown in the table below.
These throughput values are available under application metrics in the metrics screen of
NetSim.
Experiment
Number
Source Destination Application Throughput
1 Wired Node D Wired Node E FTP 0.842595
2 Wired Node A Wired Node F TELNET 0.257427
3 Wired Node B Wired Node G TELNET 0.189917
4 Wired Node B Wired Node G TELNET 0.142262
4 Wired Node C Wired Node H TELNET 0.144949

29.2.3.1 Graph I
29.2.3.2 Graph II
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1 FTP 1 FTP + 1 TELNET 1 FTP + 2 TELNET 1 FTP + 3 TELNET
FTPThroughput(Mbps)
FTP Throughput
0
0.05
0.1
0.15
0.2
0.25
0.3
1 FTP + 1 TELNET 1 FTP + 2 TELNET 1 FTP + 3 TELNET
TELNETThroughput(Mbps)
TELNET Throughput of Wired Node 1

29.2.4 Inference
From Graph I it can be inferred that FTP throughput decreases as the number of
transmitting nodes of TELNET application increases. Wired link 5 is used for FTP traffic. All
TELNET applications in this experiment also used Wired Link 5. Hence as the TELNET
traffic over wired link 5 increases the FTP throughput decreases.
From Graph II it can be inferred that TELNET throughput of Wired Node 1 decreases as
the number of transmitting nodes of TELNET application increases. TELNET traffic of wired
node 1 flows through wired link 5. Other TELNET applications also used the wired link 5.
Hence as the overall TELNET traffic over wired link 5 increases, the TELNET throughput
of Wired Node 1 decreases.

User Datagram Protocol (UDP) and Header30.
Fields
Refer: Study theory from NetSim “Basic Menu Internetwork UDP
Introduction”
Refer: Study theory from NetSim “Basic Menu Internetwork UDP UDP
Protocol Header Format”

Understand the working of “Connection31.
Establishment” in TCP using NetSim.
Note: NetSim Standard Version is required to run this Experiment.
31.1.1 Theory
When two processes wish to communicate, their TCP‟s must first establish a connection i.e.
initialize the status information on each side. Since connections must be established between
unreliable hosts and over the unreliable internet communication system, a “three-way
handshake” with clock based sequence numbers is the procedure used to establish a
Connection. This procedure normally is initiated by one TCP and responded by another TCP.
The procedure also works if two TCPs simultaneously initiate the procedure. When
simultaneous attempt occurs, each TCP receives a “SYN” segment which carries no
acknowledgement after it has sent a “SYN”.
The simplest three-way handshake is shown in the following figure.
TCP A TCP B
1. CLOSED LISTEN
2. SYN-SENT  <A: SEQ=100><CTL=SYN> SYN-RECEIVED
3. ESTABLISHED ` <B: SEQ=300><ACK=101><CTL=SYN, ACK> SYN-RECEIVED
4. ESTABLISHED  <A: SEQ=101><ACK=301><CTL=ACK> ESTABLISHED
5. ESTABLISHED  <A: SEQ=101><ACK=301><CTL=ACK><DATA> ESTABLISHED
Fig: Basic 3-Way Handshake for Connection Synchronization
Explanation:
The above figure should be interpreted in the following way. Each line is numbered for
reference purposes. Right arrows () indicates the departure of a TCP Segment from TCP A
to TCP B, or arrival of a segment at B from A. Left arrows ( ) indicates the reverse.TCP
states represent the state AFTER the departure or arrival of the segment (whose contents are
shown in the center of each line).Segment contents are shown in abbreviated form, with
sequence number, control flags, and ACK field. In line2 of the above figure, TCP A begins
by sending a SYN segment indicating that it will use sequence numbers starting with

sequence number 100. In line 3, TCP B sends a SYN and acknowledges the SYN it received
from TCP A. Note that the acknowledgment field indicates TCP B is now expecting to hear
sequence 101, acknowledging the SYN which occupied sequence 100. At line 4, TCP A
responds with an empty segment containing an ACK for TCP B's SYN; and in line 5, TCP A
sends some data.
31.1.2 Procedure
Step1:
Step2:
Click & drop Wired Nodes and Router onto the Simulation Environment and link them as
shown below.
Step3:
To run the simulation, drop the Application icon and change the Application_type to FTP.
The Source_Id is 1 and Destination_Id is 2.

Router Properties: Accept default properties for Router.
 Select the required attributes and click OK. Once the simulation is completed, the file
gets stored in the location specified.
Note: Make sure that after enabling the packet trace you select the TCP option in the
Internetworks and then select the required attributes.
After clicking on “Run Simulation”, edit IP and ARP Configuration tab by setting Static
ARP as Disable.

31.2 Output
The following results will be obtained:
Click on Open Packet Trace for performing
Packet Trace analysis
Fig: 3-way Handshake using packet trace.
31.3 Inference
In MS Excel go to DATA and select FILTER option to view only the desired rows and
columns as shown in the figure
Line 1, 2, 3 and 4 of the above table are ARP related packets and not of interest to us in this
experiment.
In line 9 of the above figure we can see that NODE-1 is sending a control packet of type
TCP_SYN requesting the connection with the NODE-2, and this control packet is first sent to

the ROUTER-3 (receiver ID). In line 10, the ROUTER-3 is sending the TCP_SYN packet
that has been received from NODE-1 to the NODE-2. In line 11, NODE-2 is sending the
control packet of type TCP_SYN_ACK to NODE-1, and this control packet is first sent to
the ROUTER-3. This TCP_SYN_ACK is the ACK packet for the TCP_SYN packet. In line
12, ROUTER-3 is sending the TCP_SYN_ACK, (received from NODE-2) to the NODE-1.
In line 13, NODE-1 is sending the TCP_ACK to NODE-2 via ROUTER-3 making the
CONNECTION_STATE as TCP_ESTABLISHED.
Once the connection is established, we see that a packet type of type “FTP” is sent from the
NODE-1 to the NODE-2 in line 14.

Simulating a three node point-to-point32.
network and applying relevant applications
over TCP and UDP
32.1 Objective:
Simulate a three node point-to-point network with the links connected as follows:
n0 – n2, n1 – n2 and n2 – n3. Apply TCP agent between n0-n3 and UDP between n1-n3.
Apply relevant applications over TCP and UDP agents changing the parameter and determine
the number of packets sent by TCP / UDP. (n0, n1 and n3 are nodes and n2 is router.)
32.2 Theory:
TCP:
TCP recovers data that is damaged, lost, duplicated, or delivered out of order by the internet
communication system. This is achieved by assigning a sequence number to each octet
transmitted, and requiring a positive acknowledgment (ACK) from the receiving TCP. If the
ACK is not received within a timeout interval, the data is retransmitted. At the receiver side
sequence number is used to eliminate the duplicates as well as to order the segments in
correct order since there is a chance of “out of order” reception. Therefore, in TCP no
transmission errors will affect the correct delivery of data.
UDP:
UDP uses a simple transmission model with a minimum of protocol mechanism. It has no
handshaking dialogues, and thus exposes any unreliability of the underlying network protocol
to the user's program. As this is normally IP over unreliable media, there is no guarantee of
delivery, ordering or duplicate protection.
32.3 Procedure:
To Create Scenario, goto Simulation  New  Internetworks.
Click & drop Router, Wired Nodes and Application onto the Simulation Environment
from tool bar as shown below.

32.4 Sample Inputs:
Sample 1
Set the properties for the devices and links as shown below:
Wired Node Properties Wired Node B Wired Node C
TCP Enable Disable
UDP Disable Enable
Application Properties:
Application Type Custom Custom
Source ID 2(Wired Node B) 3(Wired Node C)
Destination ID 4(Wired Node D) 4(Wired Node D)
Packet Size
Value(Bytes) 1460 1460
Inter Arrival Time
Value(µs) 10000 10000

To add an application, click add button in application property
Router Properties:
Accept the default properties for Router.
Accept the default properties for all Wired Links.
 Set the properties for Wired Nodes, Switches, Wired Links and Application.
 Then click on Run simulation).
Sample 1: Wired Node B and Wired Node C transmit data to Wired Node D with the Packet
Inter Arrival Time as 10000 µs.
Likewise do the Sample 2 and Sample 3 by decreasing the Packet Inter Arrival Time as
5000 µs and 2500 µs respectively.
(Note: “Packet Inter Arrival Time (µs)” field is available in Application Properties)
 Set the properties for Wired Nodes, Router, Wired Links and Application.
 Then click on Run simulation).
32.5 Comparison Chart:
(Note: The Number of Segments Sent, Segments Received and Datagram Sent, Datagram
Received will be available in the TCP Metrics and UDP Metrics of “Performance Metrics”
screen of NetSim)

32.6 Graph I
(Note: The “Packets transmitted successfully” for TCP is Segments Received and for UDP
is Datagram Received of the destination node i.e., Wired Node 3)
Number of packets transmitted successfully in TCP and UDP
32.7 Graph II
(Note: To get the “No. of packet lost”, For TCP, get the difference between Segments Sent
and Segments Received and for UDP, get the difference between Datagram Sent and
Datagram Received)
Number of lost packets in TCP and UDP
0
10000
20000
30000
40000
50000
Exp 1 Exp 2 Exp 3
PacketsTransmitted
Successfully
Inter arrival time (Micro Sec)
TCP vs UDP
TCP
UDP
0
10
20
30
40
50
60
70
80
90
100
Exp 1 Exp 2 Exp 3
No.ofPacketLost
Experiment List
TCP
UDP

32.7.1 Inference:
Graph I, shows that the number of successful packets transmitted in TCP is greater than (or
equal to) UDP. Because, when TCP transmits a packet containing data, it puts a copy on a
retransmission queue and starts a timer; when the acknowledgment for that data is received,
the segment is deleted from the queue. If the acknowledgment is not received before the
timer runs out, the segment is retransmitted. So even though a packet gets errored or dropped
that packet will be retransmitted in TCP, but UDP will not retransmit such packets.
As per the theory given and the explanation provided in the above paragraph, we see in
Graph 2, that there is no packet loss in TCP but UDP has packet loss.

Study the throughputs of Slow start +33.
Congestion avoidance (Old Tahoe) and Fast
Retransmit (Tahoe) Congestion Control
Algorithms.
33.1 Theory:
One of the important functions of a TCP Protocol is congestion control in the network. Given
below is a description of how Old Tahoe and Tahoe variants (of TCP) control congestion.
Old Tahoe:
Congestion can occur when data arrives on a big pipe (i.e. a fast LAN) and gets sent out
through a smaller pipe (i.e. a slower WAN). Congestion can also occur when multiple input
streams arrive at a router whose output capacity is less than the sum of the inputs. Congestion
avoidance is a way to deal with lost packets.
The assumption of the algorithm is that the packet loss caused by damaged is very small
(much less than 1%), therefore the loss of a packet signals congestion somewhere in the
network between the source and destination. There are two indications of packets loss: a
timeout occurring and the receipt of duplicate ACKs
Congestion avoidance and slow start are independent algorithms with different objectives.
But when congestion occurs TCP must slow down its transmission rate and then invoke slow
start to get things going again. In practice they are implemented together.
Congestion avoidance and slow start requires two variables to be maintained for each
connection: a Congestion Window (i.e. cwnd) and a Slow Start Threshold Size (i.e. ssthresh).
Old Tahoe algorithm is the combination of slow start and congestion avoidance. The
combined algorithm operates as follows,
1. Initialization for a given connection sets cwnd to one segment and ssthresh to 65535
bytes.

2. When congestion occurs (indicated by a timeout or the reception of duplicate ACKs),
one-half of the current window size (the minimum of cwnd and the receiver‟s advertised
window, but at least two segments) is saved in ssthresh. Additionally, if the congestion is
indicated by a timeout, cwnd is set to one segment (i.e. slow start).
3. When new data is acknowledged by the other end, increase cwnd, but the way it increases
depends on whether TCP is performing slow start or congestion avoidance.
If cwnd is less than or equal to ssthresh, TCP is in slow start. Else TCP is performing
congestion avoidance. Slow start continues until TCP is halfway to where it was when
congestion occurred (since it recorded half of the window size that caused the problem in
step 2). Then congestion avoidance takes over.
Slow start has cwnd begins at one segment and be incremented by one segment every time an
ACK is received. As mentioned earlier, this opens the window exponentially: send one
segment, then two, then four, and so on. Congestion avoidance dictates that cwnd be
incremented by 1/cwnd, compared to slow start‟s exponential growth. The increase in cwnd
should be at most one segment in each round trip time (regardless of how many ACKs are
received in that RTT), whereas slow start increments cwnd by the number of ACKs received
in a round-trip time.
Tahoe (Fast Retransmit):
The Fast retransmit algorithms operating with Old Tahoe is known as the Tahoe variant.
TCP may generate an immediate acknowledgement (a duplicate ACK) when an out-of-order
segment is received out-of-order, and to tell it what sequence number is expected.
Since TCP does not know whether a duplicate ACK is caused by a lost segment or just a re-
ordering of segments, it waits for a small number of duplicate ACKs to be received. It is
assumed that if there is just a reordering of the segments, there will be only one or two
duplicate ACKs before the re-ordered segment is processed, which will then generate a new
ACK. If three or more duplicate ACKs are received in a row, it is a strong indication that a
segment has been lost. TCP then performs a retransmission of what appears to be the missing
segment, without waiting for a re-transmission timer to expire.

33.2 Procedure:
Sample Inputs:
Sample 1.a: Old Tahoe (1 client and 1 server)
In this Sample,
 Total no of Node used: 2
 Wired Node C is connected with Router A by Link 1.
 Router A and Router B are connected by Link 2.
 Wired Node D is connected with Router B by Link 3.

Set the properties for each device by following the tables,
Source_Id 4(Wired Node D)
Destination_Id 3(Wired Node C)
Packet Size
Value (bytes) 1460
Inter Arrival Time
Value (micro secs) 1300
Node Properties: In Transport Layer properties, set
TCP Properties
MSS(bytes) 1460
Congestion Control Algorithm Old Tahoe
Window size(MSS) 8
Link Properties Link 1 Link 2 Link 3
Max Uplink Speed (Mbps) 8 10 8
Max Downlink Speed(Mbps) 8 10 8
Uplink BER 0.000001 0.000001 0.000001
Downlink BER 0.000001 0.000001 0.000001
Upon completion of simulation, “Save” the experiment.

 Set the properties of Node, Router& Link
Sample 1.b: Tahoe (1 client and 1 server)
Open sample 1.a, and change the TCP congestion control algorithm to Tahoe (in Node
Properties). Upon completion of simulation, “Save” the experiment as sample 1.b.
Sample 2.a: Old Tahoe (2 clients and 2 servers)
In this Sample,
 Total no of Wired Nodes used: 4
 Wired Node A and Wired Node B are connected with Router C by Link 1 and Link 2.
 Router C and Router D are connected by Link 3.
 Wired Node E and Wired Node F are connected with Router D by Link 4 and Link 5.
 Wired Node A and Wired Node B are not transmitting data in this sample.

Application Properties Application 1 Application 2
Source_Id 5 6
Destination_Id 1 2
Packet Size
Value (bytes) 1460 1460
Inter Arrival Time
Value (micro secs) 1300 1300
NOTE: The procedure to create multiple applications are as follows:
Step 1: Click on the ADD button present in the bottom left corner to add a new
application.

TCP Properties
MSS(bytes) 1460
Congestion Control Algorithm Old Tahoe
Window size(MSS) 8
Link Properties Link 1 Link 2 Link 3 Link 4 Link 5
Max Uplink Speed
(Mbps)
8 8 10 8 8
Max Downlink Speed
(Mbps)
8 8 10 8 8
Uplink BER 0.000001 0.000001 0.000001 0.000001 0.000001
Downlink BER 0.000001 0.000001 0.000001 0.000001 0.000001
 Set the properties of Node , Router & Link
Sampe 2.b: Tahoe (2 clients and 2 servers)
Do the experiment as sample 2.a, and change the congestion control algorithm to Tahoe.

Sample 3.a: Old Tahoe (3 clients and 3 servers)
In this Sample,
 Total no of Nodes used: 6
 Wired Node A, Wired Node B & Wired Node C is connected with Router D by Link 1,
Link 2 & Link 3.
 Router D and Router E are connected by Link 4.
 Wired Node F, Wired Node G & Wired Node H is connected with Router E by Link 5,
Link 6 & Link 7.
 Wired Node A, Wired Node B and Wired Node C are not transmitting data in this sample.
Application
Properties
Application 1 Application 2 Application 3
Source_Id 6 7 8
Destination_Id 1 2 3
Packet Size

Value (bytes) 1460 1460 1460
Inter Arrival Time
Value (micro sec) 1300 1300 1300
TCP Properties
MSS(bytes) 1460 1460 1460
Congestion Control
Algorithm
Old Tahoe Old Tahoe Old Tahoe
Window size(MSS) 8 8 8
Link
Properties
Link 1 Link 2 Link 3 Link 4 Link 5 Link 6 Link 7
Max Uplink
Speed
(Mbps)
8 8 8 10 8 8 8
Max
Downlink
Speed(Mbps)
8 8 8 10 8 8 8
Uplink BER 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001
Downlink
BER
0.000001 0.000001 0.000001 0.000001 0.000001 0.000001 0.000001
Simulation Time- 10 Sec
 Set the properties of Node, Router & Link

Sample 3.b: Tahoe (3 clients and 3 servers)
Do the experiment as sample 3.a, and change the TCP congestion algorithm to Tahoe. Upon
completion of simulation, “Save” the experiment.
33.3 Output
Comparison Table:
TCP
Downloads
Metrics
Slow start +
Congestion avoidance
Fast
Retransmit
1 client and 1
server
Throughput(Mbps) 5.894896 6.119152
Segments Retransmitted +
Seg Fast Retransmitted
198 200
2 clients and 2
servers
397 415
3 clients and 3
servers
408 426
Note: To calculate the “Throughput (Mbps)” for more than one application, add the
individual application throughput which is available in Application Metrics (or Metrics.txt)
of Performance Metrics screen. In the same way calculate the metrics for “Segments
Retransmitted + Seg Fast Retransmitted” from TCP Metrics  Connection Metrics
33.4 Inference:
User lever throughput: User lever throughput of Fast Retransmit is higher when compared
then the Old Tahoe (SS + CA). This is because, if a segment is lost due to error, Old Tahoe
waits until the RTO Timer expires to retransmit the lost segment, whereas Tahoe (FR)
retransmits the lost segment immediately after getting three continuous duplicate ACK‟s.
This results in the increased segment transmissions, and therefore throughput is higher in the
case of Tahoe

Subnetting34.
The objective can be executed in NetSim using the programming exercise available, under
programming user has to select IPV4 Addressing
34.1 How to Proceed:
programming user has to select IPV4 Addressing  Subnetting
This section guides the user to link his/her own code for Sub-netting to NetSim.
Pre - Conditions
The user program should read the inputted scenario from text file named „Input‟ with
extension txt.
„Output’ with extension txt.
The path of the input file and the output file can be viewed on clicking the Button “Path” in
NetSim.
Note:The temporary directory is navigated through the following step.
Executing the required concept and,

File Format
Class=B
Network_Address=128.0.0.0
No_of_Subnets=2
Host_IP_Address=128.0.0.89
The Output file contains the Default mask (in decimal),
Network portion of Default mask (in binary), Host portion
of Default mask (in binary), Subnet mask bit value, Network
portion of Subnet mask (in binary), Host portion of Subnet
mask (in binary), Subnet mask (in decimal), number of zero
in host portion, number of host in each subnet, Host address,
subnet number of the given host, subnet address of the given
host and Subnet address, Starting address, Ending address,
Broadcast address of each subnet.
The Output File format
Default mask (in decimal)>
Network portion of Default mask (in binary)>Host portion
of Default mask (in binary)>
Subnet mask bit value>
Subnet mask (in decimal)>
Network portion of Subnet mask (in binary)>Host portion of
Subnet mask (in binary)>
Number of zero in host portion,>Number of host in each
subnet>
Host address>Subnet number of the given host >Subnet
address of the given host>
Subnet address>Starting address>Ending address>Broadcast
address >
.
.
.until number of subnet is reached
Sample Output text Format
255.255.0.0
11111111 11111111>00000000 00000000>
1>
255.255.128.0>
11111111 11111111 1>0000000 00000000>
15>32766>

128.0.0.89>1>128.0.0.0>
1>128.0.0.0>128.0.0.1>128.0.127.254>128.0.127.255>
2>128.0.128.0>128.0.128.1>128.0.255.254>128.0.255.255>
Interface source code written in C is given using this the user can write only the Leaky
bucket algorithm inside the function fnSubnet () using the variables already declared. To
view the interface source code, go to
NetSim Installation path / src / Programming/ Subnet.c
Sample Scenarios:
Objective - To understand the concept of Subnetting through programming.
How to Proceed –
programming user has to select Subnetting,
Sample Inputs - In the Input panel the following steps need to be done,
 SampleMode should be selected.
 Select the Class Name
 Select the Network Address from the given list.
 Select the Number of Subnets from the given list.
 Select the Host IP Address.

 Then Run button need to be clicked. Refresh button can be used if new
Output - The following steps are under gone internally,
 Subnet mask value is obtained.
 Number of host in the each subnet is obtained
 Subnet address, Starting address, Ending address and Broadcast address are
obtained.
 Subnet address of the given Host IP address is obtained.
 Once the sample experiment is done, then Refresh button can be clicked to
create New Samples.

Network Address35.
programming user has to select IPV4 Addressing  Network Address
This section guides the user to link his/her own code for Network Addresses to NetSim.
Pre - Conditions
The user program should read the input from text file named „Input‟ with extension txt.
The user program after executing the concept should write the required output to a file
named „Output’ with extension txt.
File Format
Input File Output File
IP_Address=192.168.0.140
Prefix_Value=1
Binary value of IP Address>
Prefix value>
Binary value of Address mask>
Binary value of Network Address>
Decimal value of Network Address>.

11000000 10101000 00000000 10001100 >1>
10000000 00000000 00000000 00000000>
10000000 00000000 00000000 00000000>
128>0>0>0>
Interface source code written in C is given using this the user can write only the
fnNetworkAddress () function using the variables already declared. To view the interface
source code, go to
NetSim Installation path / src / Programming/ NetworkAddress.c
Sample Scenarios:
Objective - To understand the concept of finding Network Address through programming.
 Select the IP Address
 Select the Prefix value
Output - The following steps are done internally,
 Binary value of IP Address is obtained.

 Binary value of Address Mask is obtained
 Binary value of Network Address is obtained
 Decimal value of Network Address is obtained
create New Samples.

Special Addresses36.
programming user has to select IPV4 Addressing  Special Addresses
This section guides the user to link his/her own code for Special Addresses to NetSim.
Pre - Conditions
The user program should read the input scenario from text file named „Input‟ with
extension txt.
File Format
Input File Output File
IP_Address=192.168.0.160
Prefix_Value=5
Binary value of IP Address>
32>Prefix value>Suffix value>
Binary value of Prefix Part> Binary value of
Suffix Part>

Condition number in the table>condition>
Type of address>.
11000000 10101000 00000000 10100000 >
32>5>27>
11000>000 10101000 00000000 10100000>
It doesn't Satisfy the four conditions>
Not a special address>
Interface source code written in C is given using this the user can write only the
fnSpecialAddress () function using the variables already declared. To view the interface
source code, go to
NetSim Installation path / src / Programming/ HammingCode.c
Sample Scenarios:
Objective - To understand the concept of Special Addresses through programming.
 Select the IP Address in slash notation
Output - The following steps are done internally,
 Binary value of IP Address is obtained.

 Binary value of Address Mask is obtained
 Prefix, Suffix values are obtained
 Binary value of Prefix part and Suffix part are obtained
 Type of address is obtained
create New Samples

Classless Inter Domain Routing (CIDR), CIDR37.
Subnet addressing
programming user has to select IPV4 Addressing
37.1 Classless InterDomain Routing
37.1.1 How to Proceed:
programming user has to select IPV4 Addressing Classless Inter Domain Routing
This section guides the user to link his/her own code for Classless Inter Domain Routing to
NetSim.
Pre - Conditions
The user program should read the inputted scenario from text file named „Input‟ with
extension txt.
The path of the input file and the output file can be viewed on clicking the Button “Path” in
NetSim.
Note:
The temporary directory is navigated through the following step.

File Format
This gives the contents of the
„Input. Txt‟ from which the user has
to get the values.
The Input File contains:
Starting_IP_Address=150.0.0.0
No_of_Networks=3
No_of_Hosts_in_Network_1=512
Host_IP_Address=150.0.1.2
The Output file contains the First address, Last
address, Mask, Value and Network Address of
all the networks.
First Address: The Starting Address of the
Network
Last Address: The last address in the Network.
Mask: The Mask address (Mask should be 4 byte
format).
Number of Node: The number of nodes in the
network.
Value: The value will be either 0 or 1.
0 - The next line has the network address to
which the given host belongs.
1 - Means that the host does not belong to any
network.
Network Address: If the Value is 1 then the
network to which the host belongs is given.
Note: Each data will have a separate line and
each line will end with ">"
A Sample Output File Format
150.0.0.0>
150.0.1.255>
255.255.254.0>
512>
150.0.4.0>
150.0.7.255>
255.255.252.0>
1024>
150.0.8.0>
150.0.15.255>

255.255.248.0>
2048>
0>
150.0.0.0>
For each network there will be first address, last
address, mask and number of hosts. Since the
input is 3 networks, there are 3 set of outputs.
The last two lines give the details about whether
the host is present in any of the network.
Interface source code written in C is given using this the user can write only the CIDR inside
the function fnCIDR () using the variables already declared. To view the interface source
code, go to
NetSim Installation path / src / Programming/ CIDR.c
Sample Scenarios:
Objective - To Implement Classless InterDomain Routing (CIDR).
How to Proceed? - The objective can be executed in NetSim using the programming
exercise available, under programming user has to select Classless InterDomain Routing,
Sample Input - By using the Input Panel that is available on the left hand side a Sample
Scenario is created. The Steps involved in creating are as follows,
 Select the Starting IP Address from the given range.
 Select the No. of Networks from the given range. Maximum of 6 networks
can be selected.

 Select the No. of Hosts from the given range.
 Click on Add button to add the No.ofHosts onto the Hosts Field. The use of
Add button depends on the No. of Networks selected. If a new No. of Hosts
has to be added then remove button can be used.
 Select the Host IP Address.
Output - The following steps are under gone internally,
 Based on the Starting IP Address a table is obtained.
 There are 4 columns available in the output table, i.e. First Address, Last
Address, CIDR Mask and No. of Hosts.
 The First Address of the first network would be nothing but the Starting IP
Address which is selected. No. of rows in the table depends on the No. of
Networks selected.
 The Last Address depends on depends on the No. of Host selected.
 CIDR Mask is obtained internally by using the following formula,
CIDR Mask = 32 - (log (No. of Host) / log (2))
create New Samples.

Implementation of QoS in IEEE 802.11e38.
Network
38.1 Theory:
IEEE 802.11e Medium Access Control (MAC) is an emerging supplement to the IEEE
802.11 Wireless Local Area Network (WLAN) standard to support Quality-of-Service (QoS).
The 802.11e MAC is based on both centrally-controlled and contention-based channel
accesses. The standard is considered of critical importance for delay-sensitive applications. It
offers all subscribers high-speed Internet access with video, audio, and voice over IP.
38.2 Procedure:
Step 1:
Sample 1:
Step 2:
Create scenario as per the screen shot:
Devices Required:
2 Wireless Node, 1 Access point,
1 Router, 1 Wired Node

Step 3:
Access Point Properties AP C
Global Properties
X_Coordinate 250
Y_Coordinate 100
Step 4:
Wireless Node Properties Wireless Node B Wireless Node C
Global Properties
X_Coordinate 300 250
Y_Coordinate 100 150
Step 5:
Node properties: Disable TCP in all nodes in Transport layer as follows:
Right click on Wireless link and Change the channel characteristics as “No Path Loss”

Right click on Wired link and Change the Bit Error Rate
Wired Link Properties
Bit Error Rate 0
Access Point Properties:
Right click on access point properties. In interface1_Wireless, enable IEEE802.11e and set
the buffer size as 5 as shown in below figure:-
Wireless Node Properties:
Right click on Wireless Node and in Interface1_Wireless, enable IEEE802.11e

Step 6:
Select the Application Button and click on the gap between the Grid Environment and the
ribbon. Now right click on Application and select Properties as shown below:
NOTE: The procedure to create multiple applications are as follows:
Step 1: Click on the ADD button present in the bottom left corner to add a new
application.
Application Type Voice CBR
Source ID 1 (Wired Node E) 1(Wired Node E)
Destination ID 4 ( Wireless Node C) 5( Wireless Node B)
Codec Custom -
Packet Size
Value(Bytes) 1000 1000
Inter Arrival Time
Value(µs) 800 800

After completion of the experiment, “Save” the experiment as Sample 1.
Sample 2:
Open Sample 1, and disable IEEE_802.11e in both Access point and Wireless Node
properties and run the simulation for 10 seconds.
38.3 Output
Comparison Table:
38.4 Inference
802.11e is a proposed enhancement to the 802.11a and 802.11b Wireless LAN (WLAN)
specifications. It offers quality of service including which prioritization of voice, video and
data transmissions. Hence Throughput is obtained for voice transmission.
IEEE 802.11e Application Generation rate
(Mbps)
Throughput
(Mbps)
Delay
(Micro. Sec.)
Enable Voice 10 4.67 2782736.5
CBR 10 0.0 0
Disable Voice 10 2.28 4099938.2
CBR 10 2.28 4100423.3

ETE 802 TELECOM NETWORK MANAGEMENT
Study the effect of Peak Cell Rate (per Sec)39.
and Cell Delay Variation Tolerance on the
performance of an ATM Networks
39.1 Theory:
QoS Parameters
Primary objective of ATM is to provide QoS guarantees while transferring cells across the
network. The three main QoS parameters specified for ATM which indicate the performance
of the network are:
 Cell Transfer Delay (CTD): The delay experienced by a cell between the first bit of
the cell is transmitted by the source and the last bit of the cell is received by the
destination.
 Peak to Peak Cell Delay Variation (CDV): The difference of the maximum and
minimum CTD experienced during the connection.
 Cell Loss Ratio (CLR): The percentage of cells lost in the network due to error or
congestion that are not received by the destination.
Peak Cell Rate (PCR) specifies the rate in cells per sec that a source is never allowed to
exceed.
Procedure:
Please navigate through the below given path to,
 Create Scenario: “Simulation  New Legacy Networks  ATM”.

Inputs
In this Sample,
 Total no of CPEs used: 2
 Total no of Switches used: 2
 CPE 1 and CPE 2 are connected via Link 1 and Link 3 to Switch 1 and Switch 2
respectively.
 Switch 1 is connected to Switch 2 by Link 2.
Set the properties of Switch and CPE by following the tables for each sample,
Switch Properties Switch 1 Switch 2
Scheduling Technique Priority Priority
Buffer Size (KB) 8 8
Link Properties Link 1 Link 2 Link 3
Bit Error Rate No Error No Error No Error
Physical Medium E0 E0 E0
Distance (km) 1 1 1

Inputs for Sample 1
CPE Properties:
Inputs for Sample 2, Sample 3, Sample 4 and Sample 5:
The following properties are changed for Sample 2, Sample 3, Sample 4 and Sample 5: (rest
is same as in Sample 1)
CPE Properties Sample 2 Sample 3 Sample 4 Sample 5
Peak Cell Rate
(cells/second)
2000 3000 4000 5000
Cell Delay Variation
Tolerance (µs)
2000 3000 4000 5000
Output
To view the output by using NetSim Sample experiments need to be added onto the
Analytics interface.Given below is the navigation for analytics -
“SimulationAnalytics”
Select the experiments by selecting
 Legacy Networks
 Select the Experiments (Note: Click one experiment after another to compare the
experiments in the Analytics interface).
 Select the Metric: Queuing Delay (ms)

Comparison Charts:
39.2 Inference
When the Peak Cell Rate and Cell Delay Variation Tolerance are changed from 1000 to
5000, the Number of Cells transmitted increases. This is because the conformance of the
traffic depends on the Peak Cell Rate and the Cell Delay Variation Tolerance. As the number
of cells transmitted increases, queuing delay also increases.

Network performance analysis with an ATM40.
switch implementing different scheduling
techniques like First in First out (FIFO),
Priority, and Round Robin
40.1 Theory
In an ATM network, scheduling of cells is the major task of any ATM switch. Scheduling is
the process by which the ATM switch determines the sequence of flow of the cells in
network. The scheduling is done on various properties like service type, cell category, queue
length, arrival time etc.
First In First out (FIFO): FIFO is the simplest way of scheduling. As the name suggests, in
this technique, the preference is given to that cell which comes first in the queue irrespective
of its priority value. The one which comes next waits until the first finishes. The drawback of
this technique is that some cells of very high priority like audio service encounter extra delay
that is not ignorable.
Priority: In this technique, each cell is assigned a certain priority value based on its traffic
parameters. The scheduler checks the availability of highest priority cells and schedules them
before going for the lower priority cells. The drawback of this algorithm is that cells of
lowest priority starve for the resources when there are a large number of higher priority cells.
Round Robin: In this technique, the scheduler gives equal preference for all priority types.
Therefore, scheduler processes one cell of each priority type (If available) before going for
the next cell and cycles through them. Here starvation never occurs because no priority is
given. Round robin scheduling may not be desirable if QoS of the different priority type are
highly variable.

40.2 Procedure:
In this experiment, we are going to analyze the link Utilization (%) of the outgoing link from
an ATM switch
First in First out (FIFO):
In NetSim, Select “SimulationNewLegacy Networks ATM”
Inputs
In all Samples,
 Total no of CPEs used: 4
 Total no of ATM switches used: 2
The devices are interconnected as given below
 CPE 1 is connected to Switch 1 by Link 1.
 CPE 4 is connected to switch 2 by Link 5.
 Switch 1 and Switch 2 are connected via Link 3.

Scheduling technique FIFO FIFO
Buffer size 4096 KB 4096 KB
CPE 1 Properties CPE 1
Destination CPE 3
Transmission Type Point to Point
Traffic Type Data
Scheduling FIFO
Peak cell rate (cells/sec) 99999
Cell delay Variation tolerance (µs) 99999
GCRA type VSA
Data Input Configuration for CPE 1:
Application Data Size
Mean Application Data Size (bytes) 10000
Inter arrival time
Mean Inter-arrival time (µs) 10000
Generation rate (Mbps) 8
CPE 2 Properties CPE 2
Destination CPE 4
Transmission Type Point to Point
Traffic Type Voice
Scheduling FIFO

Peak cell rate (cells/sec) 99999
Cell delay Variation tolerance (µs) 99999
GCRA type VSA
Voice Input Configuration for CPE 2:
Codec Constant
Application Data Size (bytes) 10000
Inter-arrival time (µs) 20000
Service Type CBR
Generation rate (Mbps) 4
Link Properties Link 1 Link 2 Link 3 Link 4 Link 5
Bit Error Rate
(BER)
No Error No Error No Error No Error No Error
Physical medium E2 E2 E0 T1 T1
Data Rate (Mbps) 8.448 8.448 0.064 1.54 1.54
Distance 1 1 1 1 1
Simulation Time –10 sec
 Set the properties of CPE and Switch,
“Save” it, upon completion of the experiment.

Output:
Select the metrics Utilization and Delay report (Link). Note down the link utilization of Link
4 and Link 5.
Priority:
Follow the same steps as above in First in First out (FIFO) to create scenario and set the
properties of all devices.
Edit the properties of Switch as follows:
Scheduling technique Priority FIFO
Simulation Time –10 sec
“Save” it, upon completion of the experiment

Output:
4 and Link 5.
Round Robin:
Follow the same steps as above in First in First out (FIFO) to create scenario and set the
properties of all devices.
Edit the properties of Switch as follows:
Scheduling technique Round Robin FIFO
Simulation Time –10 Sec.
“Save” it, upon completion of the experiment.

Output:
4 and Link 5.
Comparison:

Traffic analysis:
CPE 1 is transmitting Data traffic (being generated at 8 Mbps) to CPE 3 through links 1, 3,
and 4. CPE2 transmitting voice traffic (being generated at 4 Mbps) to CPE4 through link 2,
3, and 5. Here, voice traffic has priority over data traffic.
Link speed of link 1 and 2 is high (8.448 mbps) as compared to data rate and also the PCR
and CDVT of CPE1 and CPE 2 are high. So there is a low probability that these cells will be
dropped. Therefore, all the cells reach switch1 where scheduling will happens.
Link speed of link 3 is very low (0.064 mbps) which means it does not have enough
resources to handle the cells. Hence, it will only pass those cells that have high priority
(based on Scheduling technique). Link speed of 4 and 5 is high compared to link 3 and so
there is no queue is buildup on switch 2. Based on what type of cells pass through link 3,
determines the utilization of the link 4 and link 5.
40.3 Inference:
As we see in chart 1 and table 1, the utilization of link 4 is double of link 5 in case of FIFO.
Because, in case of FIFO, scheduler gives preference to which cell comes first. Note that the
data rate of CPE1 is double than CPE2 data rate and link speed is same hence switch 1 gets
two cells from CPE 1 and one cell from CPE2 and schedules two packets of CPE1 and one
packet of CPE2. Therefore, the number of packet transmitted through link 4 is double than
link 5 and hence utilization is also double.

In case of priority, the utilization of the link 4 is 0.006 % and link 5 is 4.138%. This is
because the ATM scheduler gives priority to the voice traffic (generated by CPE2 to CPE4
via link 2, 3 and 5) over data traffic (generated by CPE 1 to CPE 3 via link 1, 3 and 4). The
generation rate of voice traffic is 4 Mbps which is much greater than the link speed of link 3
(0.064 Mbps). Hence, scheduler only schedules voice traffic and data traffic keeps waiting in
the queue.
In case of round robin the utilization of both the links is the same. Because, in case of Round
robin, scheduler schedules the packet in circular fashion implying one packet from CPE1 and
one packet from CPE2. Note that the data rate of CPE1 and CPE2 is sufficiently high to
ensure presence of a packet in the buffer from both the CPEs. Therefore, the number of
packets transmitted through link 4 is same as link 5 and hence utilization is also same.

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