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Refined Adaptive RED (Re-ARED or RARED) patch for NS-2

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Monday, January 16, 2012 12:01 PM Posted by Mohit P. Tahiliani

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Adaptive Random Early Detection (ARED) proposed by S. Floyd in 2001 solves most of the issues related to the parameter sensitivity of RED. ARED adaptively varies "Maximum drop probability" and automatically sets other parameters of RED. 

 Refined Adaptive RED (Re-ARED or RARED) proposed by T.-H. Kim and K.-H. Lee modifies the ARED's approach of varying "Maximum drop probability". Re-ARED attempts to bring the average queue size closer to the target range more quickly as compared to ARED. As a result, it minimizes packet drop rate and improves the overall performance of the network.

 Reference: "Refined Adaptive RED in TCP/IP Networks", Tae-Hoon Kim and Kee-Hyun Lee, SICE-ICASE International Joint Conference, pp. 3722-3725 (2006).

 The following patch provides implementation of Re-ARED (or RARED) in NS-2:

Following are the steps to be followed to apply above given patch to ns-2.34:

1. Download ns-allinone-2.34.tar.gz 

2. Download Re-ARED.patch

3. Unzip ns-allinone-2.34.tar.gz. You will get a folder named ns-allinone-2.34.

4. Paste the downloaded patch in this folder.

5. Give the following command: 

    patch -p1 < Re-ARED.patch

6. Then give ./install

If you have already installed copy of ns-allinone-2.34 then follow the below given steps to apply Re-ARED patch

1. Paste the downloaded patch in ns-allinone-2.34 folder.

2. Give the following command: 

    patch -p1 < Re-ARED.patch

3. Go in ns-allinone-2.34/ns-2.34 directory and give the following commands: 

    ./configure
    make clean
    make
    make install

You are done with it!

TCL Commands:

Please read this post before getting started with Re-ARED simulation in NS-2 "Random Early Detection (RED) in NS-2 - TCL - Part 1"

To simulate Re-ARED, you need to ensure that following two lines are added in the TCL Script:

Queue/RED set adaptive_ 1
Queue/RED set refined_adaptive_ 1 

Rest all commands remain same as explained in "Random Early Detection (RED) in NS-2 - TCL - Part 1".

Hope it helps.

Regards,
Mohit P. Tahiliani 

Nonlinear RED (NLRED) patch for NS-2

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Thursday, January 12, 2012 4:02 PM Posted by Mohit P. Tahiliani

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Random Early Detection (RED) proposed by S. Floyd and V. Jacobson in 1993 is one of the widely deployed Active Queue Management (AQM) mechanisms. However, due to its parameter sensitivity, lot of variants of RED have been proposed. Nonlinear RED (NLRED) is one such variant of RED. 

Reference: "Nonlinear RED: A simple yet efficient active queue management scheme", Kaiyu Zhou, Kwan L. Yeung, Victor O. K. Li, Elsevier Journal of Computer Networks, 50, pp. 3784-3794 (2006). 

The packet drop probability in RED is a linear function of the "average queue size". NLRED modifies the packet drop probability to be a quadratic function (and hence nonlinear function) of the "average queue size" so as to minimize the overall packet drop rate in the network. NLRED is not implemented in the allinone package of NS-2. The following patch provides the implementation of NLRED in NS-2.

Download NLRED patch for NS-2 

Following are the steps to be followed to apply above given patch to ns-2.34:

1. Download ns-allinone-2.34.tar.gz 

2. Download NLRED.patch

3. Unzip ns-allinone-2.34.tar.gz. You will get a folder named ns-allinone-2.34.

4. Paste the downloaded patch in this folder.

5. Give the following command: 

    patch -p1 < NLRED.patch

6. Then give ./install

If you have already installed copy of ns-allinone-2.34 then follow the below given steps to apply NLRED patch

1. Paste the downloaded patch in ns-allinone-2.34 folder.

2. Give the following command: 

    patch -p1 < NLRED.patch

3. Go in ns-allinone-2.34/ns-2.34 directory and give the following commands: 

    ./configure
    make clean
    make
    make install

You are done with it!

TCL Commands:

Please read this post before getting started with NLRED simulation in NS-2 "Random Early Detection (RED) in NS-2 - TCL - Part 1"

To simulate NLRED, you just need to include the following command in TCL Script:

Queue/RED set nonlinear_ 1 

Rest all commands remain same as explained in "Random Early Detection (RED) in NS-2 - TCL - Part 1".

Hope it helps.

Regards,
Mohit P. Tahiliani

Random Early Detection (RED) in NS-2 - TCL - Part 1

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Friday, August 26, 2011 1:36 PM Posted by Mohit P. Tahiliani

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Random Early Detection (RED) proposed by S. Floyd and V. Jacobson in 1993 is one of the widely deployed Active Queue Management (AQM) mechanisms. The performance of RED highly depends on the appropriate setting of atleast four parameters namely:

1. Minimum threshold
2. Maximum threshold
3. Exponential weighted moving average constant
4. Maximum drop probability

Setting appropriate values for these parameters is considered as a challenging issue and hence in 1999 S. Floyd proposed Gentle variant of RED. Later in 2001, S. Floyd proposed Adaptive RED which automatically sets all these parameters based on the network conditions.

In NS-2, the default RED which is active is Gentle RED + Adaptive RED. To simulate the Original RED proposed in 1993 by S. Floyd (because still there are several researchers who aim to address the parameter sensitivity of Original RED), following commands must be used in the TCL Script before configuring a router with RED queue:

Queue/RED set thresh_ 5
Queue/RED set maxthresh_ 15
Queue/RED set q_weight_ 0.001
Queue/RED set cur_max_p_ 0.5
Queue/RED set bytes_ false
Queue/RED set queue_in_bytes_ false
Queue/RED set gentle_ false
Queue/RED set mean_pktsize_ 1000

Note that the values used in the above commands are taken from the Original paper of RED (See References). You need to change them as per your requirements!

thresh_ = minimum threshold

maxthresh_ = maximum threshold

q_weight_ = exponential weighted moving average constant

cur_max_p_ = maximum drop probability

bytes_ and queue_in_bytes_ = indicate calculations of average queue size in bytes. Setting them to false indicates average queue size will be calculated in packets (not in bytes).

gentle_ = Gentle RED mode. Setting it false indicates Gentle mode is OFF

mean_pktsize_ = average size of a packet arriving at the router

Setting RED in Wired Networks:

Sample command is:

$ns duplex-link $n0 $n2 10Mb 10ms RED

Setting RED in Wireless Networks:

Sample command is:

set val(ifq)    Queue/RED

Gentle RED Settings in NS-2:

To enable Gentle RED option, the only change required is:

Queue/RED set gentle_ true

Rest all commands and syntax for Gentle RED are exactly same as mentioned above for Original RED.

Hope it helps.

Regards,
Mohit P. Tahiliani

References: S. Floyd and V. Jacobson, "Random Early Detection Gateways for Congestion Avoidance", IEEE/ACM Transactions on Networking, 1, 397-413.

AWK Scripts for Normalized Routing Load/Overhead

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Saturday, August 6, 2011 3:51 PM Posted by Mohit P. Tahiliani

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Normalized Routing Load (or Normalized Routing Overhead) is defined as the total number of routing packet transmitted per data packet.

It is calculated by dividing the total number of routing packets sent (includes forwarded routing packets as well) by the total number of data packets received.

AWK Script to calculate Normalized Routing Load for Old trace format can be downloaded from the link given below:

AWK Script for Normalized Routing Load - Old Trace Format:

nrl_ot.awk

AWK Script to calculate Normalized Routing Load for New trace format can be downloaded from the link given below:

AWK Script for Normalized Routing Load - New Trace Format:

nrl_nt.awk

If there are any problems encountered in downloading above files, please visit the link given below:

http://www.mediafire.com/?z1c2cxdt1a31d

These scripts work for AODV, DSDV, DSR and OLSR. To use these scripts for other routing protocols, just add the name of that routing protocol in appropriate loop within this script.

Note: Please report any bugs if encountered.

Hope it helps.

Regards,
Mohit P. Tahiliani 

Modified AOMDV with Multiple Interface Support in NS-2

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Tuesday, July 5, 2011 8:29 PM Posted by Mohit P. Tahiliani

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This patch is designed for ns-allinone-2.33.

Contributed by: Chirag Raval

 Download NS-2.33-AOMDV-Multiple-Interface.patch

Following are the steps to be followed to apply above given patch to ns-2.33:



3. Unzip ns-allinone-2.33.tar.gz. You will get a folder named ns-allinone-2.33.

4. Paste the downloaded patch in this folder.

5. Give the following command:

    patch -p1 < NS-2.33-AOMDV-Multiple-Interface.patch

6. Then give ./install

If you have already installed copy of ns-allinone-2.33 then follow the below given steps to apply multi-interface patch.

1. Paste the downloaded patch in ns-allinone-2.33 folder.

2. Give the following command:

    patch -p1 < NS-2.33-AOMDV-Multiple-Interface.patch

3. Go in ns-allinone-2.33/ns-2.33 directory.

4. Give the following commands:

    ./configure

    make clean

    make

    make install

You are done with it!

Example TCL scripts to verify the working of this patch are similar to that of TCL Scripts provided for Multi Interface DSDV patch. You need to replace DSDV by AOMDV in TCL Scripts. Scripts can be downloaded from the following link:


Kindly Note: The tcl scripts having "mesh" word in their name are the scripts designed with multiple interfaces. Others are designed with single interfaces. To verify the working of multiple interfaces, two awk scripts are also provided in the folder.

A tcl script named im3pmanual.tcl is a tcl script wherein nodes have different number of interfaces assigned to them whereas, other tcl scripts designed with multiple interface are designed such that all the nodes in the network have equal number of interfaces.
If you encounter any problem in downloading the patch from the link given above, please follow this link:


If you encounter any problem in downloading example tcl scripts, please follow this link:


Hope it helps.

Regards,
Mohit P. Tahiliani

Xgraph and AWK Scripts in NS-2

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Friday, August 6, 2010 11:21 AM Posted by Mohit P. Tahiliani

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AWK scripts (.awk), which are used to extract the necessary information from trace files (.tr) are also useful to plot graphs using Xgraph (.xgr) utility of NS-2. However, the AWK scripts that are used to plot graphs differ from the AWK scripts that just print the values on the terminal.

I will try to explain the difference between these two types of AWK scripts with the help of an example. Assume that we have designed a tcl script named “energy.tcl” which simulates a network for 100 seconds. We run this tcl script with the following command:

ns energy.tcl

After executing the tcl script we get a trace file (.tr) and a NAM file (.nam) i.e. “energy.tr” and “energy.nam”. Now we may have two scenarios as explained below:

1. We want the value of residual (remaining) energy of a node at the end of the simulation. (Here graph of Time v/s Residual energy is not required).

2. We want the value of residual (remaining) energy of a node at each instance of time i.e from beginning of the simulation to the end of the simulation. (Time v/s Residual energy graph is required to observe the decrease in the total energy of a node).

For both of the above mentioned scenarios we need to design two different AWK scripts. However, the main logic to calculate the residual energy will remain the same. Only the way we print the values differs.

Let scen1.awk be the awk file for first scenario and scen2.awk be the awk file for second scenario. scen1.awk should be designed such that when we run it by using the following command:

awk  -f  scen1.awk  energy.tr

it should print the residual (remaining) energy of a node on the terminal.

And scen2.awk should be designed such that when we run it by using the following command:

awk  -f  scen2.awk  energy.tr  >  energy.xgr

it should print two values in “energy.xgr”: time and residual (remaining) energy of a node.

If you open “energy.xgr” you will notice that there are two columns created. In first column, values related to “time” are printed and in another column values related to “residual energy” are printed. The values in first column form X-axis of the graph and the values in second column form Y-axis of the graph (thus you get a graph of Time v/s Residual Energy). Give the following command to see the graph:

xgraph  energy.xgr

Default background color of the graph is grey. If you want a graph with background color as white, give the following command:

xgraph  energy.xgr  -bg  white

Other options (like changing background colors, plotting bar graphs, etc) related to Xgraph are available in the pdf file given below:

Xgraph Utility of NS-2

Hope it helps.

Regards,
Mohit P. Tahiliani 

Modified DSDV for Multiple Interface Support in NS-2

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Wednesday, June 16, 2010 2:11 PM Posted by Mohit P. Tahiliani

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The document named "Adding multiple interface support in NS-2" prepared by Ramon Aguero Calvo and Jesus Perez Campo, University of Cantabria helps to incorporate multiple channel support to the core of the ns-2 simulator.
There are few modifications required in the routing protocols such as DSDV, AODV and DSR to use multiple interface support in ns-2. Ramon Aguero Calvo and Jesus Perez Campo have modified the AODV protocol for which code is available in the document they have provided. A patch (that contains modifications in ns-2 to support multiple interfaces and modifications in AODV code) based on that document is available on this link "Revised: Adding Multiple Interface Support in NS-2" .

Based on the guidelines provided in Chapter 5 of the document we have successfully made modifications in DSDV routing protocol. The patch for the same is available on the link given below:

 Download NS-2.33-DSDV-Multiple-Interface.patch


Following are the steps to be followed to apply above given patch to ns-2.33:



3. Unzip ns-allinone-2.33.tar.gz. You will get a folder named ns-allinone-2.33.

4. Paste the downloaded patch in this folder.

5. Give the following command:

    patch -p1 < NS-2.33-DSDV-Multiple-Interface.patch

6. Then give ./install

If you have already installed copy of ns-allinone-2.33 then follow the below given steps to apply multi-interface patch.

1. Paste the downloaded patch in ns-allinone-2.33 folder.

2. Give the following command:

    patch -p1 < NS-2.33-DSDV-Multiple-Interface.patch

3. Go in ns-allinone-2.33/ns-2.33 directory.

4. Give the following commands:

    ./configure

    make clean

    make

    make install

You are done with it!

Example TCL scripts to verify the working of the patch can be found on the link given below:



Kindly Note: The tcl scripts having "mesh" word in their name are the scripts designed with multiple interfaces. Others are designed with single interfaces. To verify the working of multiple interfaces, two awk scripts are also provided in the folder.

A tcl script named im3pmanual.tcl is a tcl script wherein nodes have different number of interfaces assigned to them whereas in other tcl scripts designed with multiple interface are designed such that all the nodes in the network have equal number of interfaces.

If you encounter any problem in downloading the patch from the link given above, please follow this link:


If you encounter any problem in downloading example tcl scripts, please follow this link:


Hope it helps.

Regards,
Mohit P. Tahiliani

Acknowledgements: I would like to Thank Chirag J. Raval and Vaidehi S. Panwala for extending their support in modifying the code of DSDV. They went in complete details of DSDV source code in NS-2 and have a major role in the implementation of this patch.

Very Important!!! Please Note: 
(1) The DSDV modifications are still under review and the patch has been verified with only few TCL scripts. Please report any bugs if encountered.
(2) This patch does not contain modifications to AODV routing protocol. However it includes Multiple Interface Support in NS-2 (i.e we have excluded the AODV Modifications from the code of Ramon Sir's document and included DSDV Modifications).
(3) A combined patch that includes Multiple Interface Support + AODV Modifications + DSDV Modifications will be uploaded soon with sample TCL Scripts. Thank you for co-operation. 
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