Queuing Models in NS2

M/M/1 is a system with poisson arrival time, servicing exponentially and a queue of unlimited capacity and type of FIFO Queue. This is the simplest queuing system.  NS2 supports various distributions like pareto, exponential, constant, unifrom, etc to handle the network dynamics and metrics. So it is very easy to test the given network link to monitor a given queue using any of these queuing models. The listing 3 and 4 are monitoring the link when DropTail queue is used with a capacity of finite and infinite. Listing 13.3 uses infinite capacity and Listing 13.4 uses Finite capacity The output screen shot is shown below the scripts for further understanding
Listing 3 – M/M/1 Queuing Model #new Simulator creation set ns [new Simulator] #trace file creation for capturing the UDP data set tf [open out.tr w] $ns trace-all $tf
#setting the exponential distribution param set lambda 30.0 set mu     33.0
#creation of nodes set n1 [$ns node] set n2 [$ns node] #The queue limit is 1Lakh as the capacity is infin…

Enable All interfaces in Wireshark

If you are running Ubuntu or Linux Mint, the wireshark may not list all the interfaces except bluetooth. There is a small workaround for enabling all the interfaces within wireshark

To install wireshark
$ sudo apt-get install wireshark

Checking for all the interfaces
$] ifconfig -a 
eth0      Link encap:Ethernet  HWaddr b4:b5:2f:90:41:98  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

lo        Link encap:Local Loopback  
          inet addr:  Mask:
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:5528 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5528 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:522095 (522.0 KB)  TX bytes:522095 (522.0 KB)

wlan0     Link encap:Ethernet  HWaddr 68:17:29:15:7f:9d  
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::6a17:29ff:fe15:7f9d/64 Scope:Link
          RX packets:487713 errors:0 dropped:0 overruns:0 frame:0
          TX packets:336698 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:591668376 (591.6 MB)  TX bytes:41118839 (41.1 MB)

To check the interfaces shown by the dumpcap

$] dumpcap -D -M (following line is the output)
1. bluetooth0 4 network

Enable the following commands in linux to make it work.
$] sudo groupadd wireshark$] sudo usermod -a -G wireshark $USER$] sudo chgrp wireshark /usr/bin/dumpcap$] sudo setcap cap_net_raw,cap_net_admin=eip /usr/bin/dumpcap

$] dumpcap -D -M (following is the output)

T S Pradeep Kumar

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