|
|
This is only a preview of the paper
Click here to register and get the full text.
Existing members click here to login
|
|
|
... A traffic source is an element of the network used to transmit data. ... (TCP Connection
TCP Sink
FTP Traffic Source
FTP Sink
Data sent from Node A to Node B
TCP (Transfer Control Protocol) is only one protocol of many that can be used to send data over a network. ... FTP (File Transfer Protocol) is used to transfer files reliably and securely across a network. ...
SNMP
Simple Network Management Protocol (SNMP) in its most basic explanation is a protocol for the management of a network. It works by a management station requesting a MIB value from a network device, which replies with the appropriate value. ...
ARP
Address Resolution Protocol (ARP) is the protocol that is used to convert the physical address of the NIC (Network Interface Card) into a valid IP address. ... 25 defines the way in which switches and computers function with a packet switch network, and permits transmission rates of 64Kbps. ...
IPX
Internet Packet Exchange (IPX) is Novell’s proprietary Network Layer protocol suite. ...
Traffic Generation
Once the network has been set up in ns a traffic generation function is needed if we are to actually witness any transfer of data between nodes. ... As we shall see later tcl is a way of creating instances of network objects defined in the simulator library. ... NAM has its own basic interface to create simple network environments, but to really understand how ns works and build more complex networks the user must understand the Tcl language. ...
EmbeddedTcl is the class used for built in commands that make any simulation easier. ...
The Role of the tk/tcl language
The role of the tcl language is to provide the user an easy way of developing a network simulation without having to know any of the more complex C++ used to invoke it. ... C++ is a fairly complex language and is not suited to people who just want to create a simple network simulation. ...
# Run the simulation
$ns run
The important thing to see at this point is how tcl is used to invoke instances of objects in the C++ library. For example, the first thing we do is set up a variable $ns to inherit all functions and object relevant to a new simulation object. ... A matching object is created in OTcl for each of the objects called in the C++ simulation directories, with corresponding functions and variables. ... How to build a simple model for ns2
Example diagram of three connected nodes displayed in NAM
In this section I will explain some of the main basic tcl code used in ns2 to set up a simple network model. ... nam &
exit 0
}
The next part of the code is standard is used in all simple network models that are built using ns2. ... tcl file
Create Network Nodes
The creation of network nodes is a fairly simple process. Nodes on a network are usually pc’s, servers, routers etc. ...
set n1 [$ns node]
set n2 [$ns node]
This creates another two network nodes.
How to link nodes together to make a network
Now that the nodes have been created they need to be linked together so that data can be sent and received. ...
How to add a protocol to the network
TCP is a protocol that is very commonly used on networks and will be used in the example I have chosen. ...
TCP is not the only protocol that could be used on the network model. ... As mentioned earlier in the paper FTP is an application widely used to transmit data between nodes on a network and is used in conjunction with TCP to do this. ... The set type command
How to plot a graph showing the output results from a simulation
X-Graph comes with the all-in-one package and can be used to plot simulation results.
The first thing we do is create output files that store data from the simulation. This code should be somewhere near the beginning of the simulation.
Approximate Word count = 3800
Approximate Pages = 15.2
(250 words per page double spaced)
|
|
|
|
|
|