Network simulator version 2 is abbreviated as Ns2 and it is considered as the open source event driven simulator that is designed particularly for the research based on computer communication networks. In addition, it is considered as the provision of supportive system to simulate the bunch of protocols including DSR, http, UDP, FTP and TCP. Most importantly, both the wired and wireless networks are simulated used this process.

Basic Architecture of Ns2

           Mainly, the process of Ns2 includes two significant languages such as object oriented tool command language (OTcl) and C++ language. When OTcl is denoted as the setup of simulation through configuring and assembling the objects and the discrete events are scheduled. On the other hand, C++ is defined as the internal mechanism or the backend of the simulation objects. TclCL is used to interlink both the OTcl and C++.

         Additionally, there are two different forms of Ns2 source code and they are enlisted in the following.

• Component wise
• All in one package
• In this process, the users will receive all the essential components in addition with the optional components. It is considered as the fundamental and recommended option for the beginners. In addition, it is providing the script for install and that is used to configure the Ns2 environment to create the executable file based on Ns2 through the utilization of make utility. This package includes two significant components and they are listed below
• Optional components
• Xgraph version 12.1
• It is considered as the data plotter along with the interactive buttons for panning, zooming, printing and selecting display options
• NAM release 1.12
• NAM is denoted as an animation tool for viewing network simulation traces and packet traces
• Zlib version 1.2.3
• It is the required library for NAM
• Main components
• TclCL release 1.18
• OTcl release 1.12
• Tcl and Tk release 8.4.13
• NS release 2.35

         The process of OTcl script simulation program to attain the network animator Ns simulator library is included and that consist some objects and modules such as.

• Network setup helping modules or plumbing modules
• Network component objects
• Event scheduler objects

Tool Command Language

        The tool command language is abbreviated as Tcl and it is considered as the simple programming language. Only few hours are required to write an interesting TCL program when that guy is programmed earlier. Additionally, it is providing a rapid overview about the foremost characteristics of Tcl.

Wired TCL Script Components

• The event scheduler is created
• Open the new files and turn on the tracing process
• Create the nodes
• Setup the links
• The traffic type is configured
• UDP
• TCP
• Set the time of traffic generation
• FTP
• CBR
• Terminate the simulation

          For your reference, our research experts have highlighted the initiations required for Ns2 to projects that are used to implement the Ns2 based research in the following.

Ns Simulator Preliminaries

• Initiation and termination aspects of Ns simulator
• Nam visualization tool
• Definition for applications and agents
• Description about topology, queues, links and network nodes

        Above mentioned are the research directions for the further research based on the Ns2.  At this point, we have highlighted the significance of structure of trace file based on the innovation of Ns2 project topics.

Structure of Trace Files

        While tracing into the output based on ASCII file, the trace is organized in 12 fields and that are listed in the following.

• pkt id
• It is about the unique id of the packet
• Seq Num
• It is the packet sequence number of network layer protocol
• The implementation of UDP in real network never include the utilization of sequence number because Ns will track the UDP packet sequence number to analyze the functions
• Dest Addr
• It is about the destination address and provides the ―node.port‖ format
• Src Addr
• It is the source address with the provision of ―node.port‖ form
• Fid
• Flow id is abbreviated as fid and it is the flow id of IPv6 in which the users are capable to set the flow in the input OTcl script and to analyze the functions
• It is deployed in the stream color specification of the NAM display
• Flags
• This process includes some flags
• PKT size
• It is about the provision of packet size
• PKT type
• It provides the packet types
• TCP
• CBR
• To node
• It is the provision of output node based on the link where the event is functioning
• From node
• It provides the input nodes which is related to link based event occurrence
• Time
• It is about the time which is required and it is functioning in the event occurrence
• Event
• It is about the event type
• It is functioning through the four significant symbols and they are listed below
• d
• Dropped
• –
• Dequeued
• +
• Enqueued
• r
• It is the depiction of receiving at the output of link

What is Grep?

          Grep is considered as filter and that is used to search the file for specific pattern of characters and displaying all the lines which includes the pattern. The regular expression is considered as the pattern that is searched in the file and here the grep depicts the global search for printout and regular expression. The composition is used for the grep and that is highlighted in the following.

                                                 grep [options] pattern [files]

     In addition, our research professionals have enlisted some descriptions about the options that are used in the grep.

• -C n
• It is the prints searched line and n lines after before the result
• -B n
• It is the depiction of prints searched line and n line before the result
• -A n
• The prints searched line and n lines after the result
• -o
• It is functioning to print only the matched parts of a matching line along with all such part on a separate output line
• -w
• It is about to match the whole word
• -E
• It provides the pattern as an extended regular expression (ERE)
• -f file
• It took patterns from file and that order one per line
• -e exp
• It is specification of expression with this option and it is capable to utilize multiple times
• -v
• It is functioning to prints out all the lines that do not matches the pattern
• -n
• It is about to display the matched lines along with its line numbers
• -l
• It is functioning to display only the list of filenames
• -i
• It ignores the case for matching
• -h
• Display the matched lines, on the other hand it do not display the filenames
• -c
• It prints only a count of the lines that match a pattern

          Consequently, let’s have a look at the beneficial and major functions of grep for your reference and they are highlighted in the following.

• Grep –i ‘word’ filename # find lines with ‘word’ regardless of case
• Grep –c ‘word’ filename # find lines with ‘word’ and print out the
• number of these lines
• grep -v ‘^[0-9]‘ filename # find lines beginning with any of the numbers from 0-9
• ls -l | grep rwxrwxrwx # list files that have ‘rwxrwxrwx’ feature
• Grep ‘word’ filename > file2 # output lines with ‘word’ to file2
• Grep ‘^word’ filename # find lines beginning with ‘word’
• Grep –v ‘word’ filename # find lines without ‘word’
• Grep ‘word’ filename # find lines with ‘word’

          Below, we have highlighted some of significant research titles which are useful for the research scholars to develop their Ns2 project topics.

Research Topics in Ns2

• A paradigm shift toward satisfaction, realism and efficiency in wireless networks resource sharing
• Network operator revenue maximization in dual powered green cellular networks
• Performance modeling of softwarized network services based on queuing theory with experimental validation
• An energy aware high performance task allocation strategy in heterogeneous fog computing environments
• Deep reinforcement learning resource allocation in wireless sensor networks with energy harvesting and relay

          To this end, we ensure that we are well equipped to provide several interesting research requirements to develop your research based Ns2 project topics. In order to give you advanced research projects, we analyze research developments in network simulation field through research papers collected from the reputed journals such as SCI, Scopus, IEEE and etc. So, reach us to shine better in your research career.