To simulate Network Layer projects utilizing NS2, we can leverage its full support for network protocols that particularly for IP-based routing, packet forwarding, and internetworking. The network layer is responsible for routing data across distinct networks and find out the optimal path for data transmission.
You can refer the procedure in the following below:
Common Aspects of the Network Layer:
- Routing Protocols: Encompasses protocols such as AODV, DSR, OSPF, RIP, and others that find out the finest paths for packets.
- IP Addressing: Replicate scenarios in which packets are forwarded according to the IP addresses.
- Packet Forwarding and Queuing: Simulate how packets are sent among the nodes and how queuing mechanisms influence the performance.
- Internetworking: Model communication between distinct kinds of networks.
- Multicasting: Manage scenarios in which data is transmitted to several destinations at once.
Steps to Simulate Network Layer in NS2
- Install NS2
Make sure we have NS2 installed on the system. If not, then we download and install it from the NS2 Official Website.
- Choose a Network Layer Protocol
NS2 supports a various kinds of routing protocols at the network layer, like:
- AODV (Ad-hoc On-Demand Distance Vector)
- DSR (Dynamic Source Routing)
- OSPF (Open Shortest Path First)
- RIP (Routing Information Protocol)
- Dijkstra’s Algorithm
- Create a TCL Script for Network Layer Simulation
Following is an instance script, which replicates a network using AODV as the network layer routing protocol. We can change this to replicate other network layer behaviors.
Example TCL Script for AODV Simulation:
# Create a simulator object
set ns [new Simulator]
# Define trace and NAM files for analysis and visualization
set tracefile [open “network_layer_trace.tr” w]
set namfile [open “network_layer_simulation.nam” w]
$ns trace-all $tracefile
$ns namtrace-all $namfile
# Define a topography for the wireless network
set topo [new Topography]
$topo load_flatgrid 500 500
# Configure the network layer with AODV as the routing protocol
create-god 10 ;# Number of nodes
$ns node-config -adhocRouting AODV \
-llType LL \
-macType Mac/802_11 \
-ifqType Queue/DropTail/PriQueue \
-ifqLen 50 \
-antType Antenna/OmniAntenna \
-propType Propagation/TwoRayGround \
-phyType Phy/WirelessPhy \
-channelType Channel/WirelessChannel \
-topoInstance $topo \
-agentTrace ON \
-routerTrace ON \
-macTrace OFF \
-movementTrace OFF
# Create nodes and set up their positions
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
set n4 [$ns node]
# Set positions of nodes manually (optional)
$n0 set X_ 50
$n0 set Y_ 100
$n1 set X_ 100
$n1 set Y_ 150
$n2 set X_ 150
$n2 set Y_ 200
$n3 set X_ 200
$n3 set Y_ 250
$n4 set X_ 250
$n4 set Y_ 300
# Create UDP agents for traffic generation and sink
set udp0 [new Agent/UDP]
set udp1 [new Agent/UDP]
# Attach agents to nodes
$ns attach-agent $n0 $udp0
$ns attach-agent $n4 $udp1
# Create a Constant Bit Rate (CBR) traffic generator
set cbr0 [new Application/Traffic/CBR]
$cbr0 set packetSize_ 512
$cbr0 set rate_ 0.5Mb
$cbr0 attach-agent $udp0
# Connect UDP agents for communication
$ns connect $udp0 $udp1
# Schedule the start and stop of the traffic flow
$ns at 1.0 “$cbr0 start”
$ns at 4.5 “$cbr0 stop”
# Define the finish procedure to close trace files
proc finish {} {
global ns tracefile namfile
$ns flush-trace
close $tracefile
close $namfile
exit 0
}
# End the simulation at 5.0 seconds
$ns at 5.0 “finish”
# Run the simulation
$ns run
- Run the Simulation
We can save the script as network_layer_simulation.tcl then execute it in NS2:
ns network_layer_simulation.tcl
- Visualize the Simulation Using NAM
We can open the .nam file in the Network Animator (NAM) to envision the network behavior and packet forwarding:
nam network_layer_simulation.nam
- Analyze the Trace File
The trace file (network_layer_trace.tr) includes detailed data regarding packet forwarding, routing decisions, and packet loss. We can examine:
- Routing decisions created by the AODV protocol.
- The path each packet takes via the network.
- Performance parameters such as packet delivery ratio, delay, and throughput.
- Modify the Simulation
- Change Routing Protocol: Change the routing protocol (e.g., OSPF, RIP, or DSR) to experiment diverse network layer behaviors.
- Node Mobility: Insert node mobility to replicate dynamic networks.
- Packet Loss and Delay: Launch packet loss and delay at the network layer to mimic realistic network conditions.
Optional Enhancements:
- Multicasting: We can be used multicast routing protocols like DVMRP or PIM to replicate multicast communication at the network layer.
- Quality of Service (QoS): Replicate diverse QoS mechanisms to prioritize particular kinds of traffic.
- Hierarchical Routing: Execute hierarchical routing to replicate larger networks with several routing domains.
With the help of offered manual, you can grasp the knowledge regarding the simulation and execution of Network Layer projects. If required, we will provide any other details relevant to this subject for you.
The specialists at phdprime.com focus on IP-based routing, packet forwarding, and internetworking for your projects. Simply provide us with the details of your Network Layer projects, and we will offer you expert simulation assistance along with insights on current trending topics.
