How to Implement Network PID Management in NS2

To implement the Network Process Identifier (PID) Management in NS2 which is not entirely a functions of the network simulation framework, because ns2 mainly intent on simulating network layers and communications instead of handling process-level operations like PIDs that is often handled by an operating system. Yet, if we want to replicate something analogous to PID management like handling flows, sessions or links amongst nodes in a way similar to how operating systems handle processes, We have to simulate it through methods includes handling flows, application sessions or distinct identifiers for traffic. We had offered the overall instructions on how to accomplish it in NS2:

Key Concepts for Simulating PID Management in NS2:

  1. Flow or Session Management: Each flow or connection amongst nodes can be treated as a process or session with a discrete identifier.
  2. Traffic Management: Handle numerous concurrent flows (sessions) amongst nodes, with distinct IDs, and manage creation, termination, and re-directing of these flows.
  3. Simulating Process Control: You can replicate starting, stopping, and observing network “processes” (such as sessions or flows) amidst nodes.

Steps to Simulate Network PID Management in NS2

  1. Define Unique Identifiers for Flows: Each flow (or session) amongst nodes can have a distinct identifier, replicating a PID-like structure.
  2. Manage Flows: You can begin and end various flows (sessions) amongst nodes to replicate process control.
  3. Monitor and Control Traffic: Track the flows and handle traffic through starting, stopping, or rerouting, alike to process management in an operating system.

Example: Simulating PID-Like Flow Management in NS2

In this sample, we will simulate multiple flows (or sessions) amongst nodes, each with a distinct identifier. The flows can be started, stopped, or redirected to replicate PID management-like activities.

Step 1: Define Nodes and Initialize Unique Flow IDs (Simulating PIDs)

# Define the simulator object

set ns [new Simulator]

# Define trace and nam files for output

set tracefile [open out.tr w]

set namfile [open out.nam w]

$ns trace-all $tracefile

$ns namtrace-all $namfile

# Define a ‘finish’ procedure to end the simulation and visualize in NAM

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam out.nam &

exit 0

}

# Set up the topography for the simulation area

set topo [new Topography]

$topo load_flatgrid 500 500

# Define the wireless channel

set chan [new Channel/WirelessChannel]

# Configure the nodes for ad-hoc communication using AODV routing protocol

$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 \

-channel $chan

# Create nodes

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Set node positions for NAM visualization

$node1 set X_ 100; $node1 set Y_ 100; $node1 set Z_ 0

$node2 set X_ 300; $node2 set Y_ 300; $node2 set Z_ 0

$node3 set X_ 500; $node3 set Y_ 100; $node3 set Z_ 0

# Step 2: Simulate PID-Like Flow Management by Assigning Unique IDs to Flows

# Unique flow IDs (similar to PIDs)

set flow_id_1 101   ;# Flow from node1 to node2

set flow_id_2 102   ;# Flow from node2 to node3

set flow_id_3 103   ;# Flow from node1 to node3

# Attach TCP agents for flows (simulating PID-based processes)

set tcp1 [new Agent/TCP]

set sink1 [new Agent/TCPSink]

$ns attach-agent $node1 $tcp1

$ns attach-agent $node2 $sink1

$ns connect $tcp1 $sink1

set tcp2 [new Agent/TCP]

set sink2 [new Agent/TCPSink]

$ns attach-agent $node2 $tcp2

$ns attach-agent $node3 $sink2

$ns connect $tcp2 $sink2

set tcp3 [new Agent/TCP]

set sink3 [new Agent/TCPSink]

$ns attach-agent $node1 $tcp3

$ns attach-agent $node3 $sink3

$ns connect $tcp3 $sink3

Step 2: Start and Stop Flows Using the Flow IDs (Simulating PID Control)

# Procedure to start a flow (simulating a process start based on flow ID)

proc start_flow {flow_id agent app start_time stop_time} {

global ns

if { $flow_id == 101 } {

# Start FTP application on flow_id 101 (from node1 to node2)

set ftp1 [new Application/FTP]

$ftp1 attach-agent $agent

$ns at $start_time “$ftp1 start”

$ns at $stop_time “$ftp1 stop”

puts “Flow $flow_id (node1 to node2) started at $start_time and stopped at $stop_time”

} elseif { $flow_id == 102 } {

# Start FTP application on flow_id 102 (from node2 to node3)

set ftp2 [new Application/FTP]

$ftp2 attach-agent $agent

$ns at $start_time “$ftp2 start”

$ns at $stop_time “$ftp2 stop”

puts “Flow $flow_id (node2 to node3) started at $start_time and stopped at $stop_time”

} elseif { $flow_id == 103 } {

# Start FTP application on flow_id 103 (from node1 to node3)

set ftp3 [new Application/FTP]

$ftp3 attach-agent $agent

$ns at $start_time “$ftp3 start”

$ns at $stop_time “$ftp3 stop”

puts “Flow $flow_id (node1 to node3) started at $start_time and stopped at $stop_time”

}

}

# Start the flows (simulating PID-like management)

start_flow 101 $tcp1 “ftp1” 1.0 3.0   ;# Start flow 101 from node1 to node2

start_flow 102 $tcp2 “ftp2” 2.0 4.0   ;# Start flow 102 from node2 to node3

start_flow 103 $tcp3 “ftp3” 3.0 5.0   ;# Start flow 103 from node1 to node3

Step 3: Simulate Termination and Monitoring of Flows

# Procedure to simulate termination of flows (simulating process termination)

proc terminate_flow {flow_id stop_time} {

if { $flow_id == 101 } {

puts “Terminating flow $flow_id (node1 to node2) at $stop_time”

} elseif { $flow_id == 102 } {

puts “Terminating flow $flow_id (node2 to node3) at $stop_time”

} elseif { $flow_id == 103 } {

puts “Terminating flow $flow_id (node1 to node3) at $stop_time”

}

}

# Terminate flows after they have completed

$ns at 3.0 “terminate_flow 101 3.0”

$ns at 4.0 “terminate_flow 102 4.0”

$ns at 5.0 “terminate_flow 103 5.0”

Step 4: Schedule the End of the Simulation

# Schedule the end of the simulation

$ns at 6.0 “finish”

# Run the simulation

$ns run

Explanation of the Script

  1. Flow Creation with Unique IDs (Simulating PIDs):
    • We state three flows with discrete identifiers (flow_id_101, flow_id_102, and flow_id_103), which simulate process-like activities in the network by handling data communication sessions amongst nodes.
  2. Starting Flows (Simulating Process Start):
    • The start_flow procedure permits us to begin various flows at certain times using their discrete flow IDs. This replicates the process of presenting tasks or network communication sessions.
  3. Flow Termination (Simulating Process Termination):
    • The terminate_flow approach simulates the termination of a flow at a particular time, reflecting the concept of process termination.
  4. Traffic Simulation:
    • TCP agents and FTP applications are included to the nodes to mimic traffic flow amongst them, which imitates network processes running with distinct IDs (alike to PIDs).

Run the Simulation

Store the script as pid_management_ns2.tcl and execute it using:

ns pid_management_ns2.tcl

This will produce a trace file (out.tr) and a NAM file (out.nam). The trace file logs the packet transmissions, and the NAM file permits you to visualize the flows (processes) running amongst the nodes.

Visualize the Simulation in NAM

Use the below command to visualize the simulation in NAM:

nam out.nam

In NAM, you will monitor nodes communicating through various flows (sessions), and these flows can be treated as analogous to processes identified by unique PIDs.

Advanced Features for Simulating PID Management in NS2

  1. Dynamic Flow Management: Replicate real-time flow generation and conclusion, where flows (like processes) can be dynamically set up and ended depends on network conditions or user-defined events.
  2. Flow Monitoring: Observe each flow’s performance like bandwidth utilization, packet loss, or delay by executing logic. This is analogous to observing the status of processes in an operating system.
  3. Priority-Based Flow Management: Allocate priorities to flows, and handle them in terms of their priority, alike to how operating systems plan processes.
  4. Flow Redirection (Re-routing): Establish the potential to re-direct flows dynamically, simulating how PIDs can be handled and reallocated during process migration.

We have presented the detailed demonstration on how to implement the Network Process Identifier (PID) Management using ns2 simulation tool through this manual. Also, you can attach advanced mechanisms into the simulation network. You can refer the sample snippets, if needed. Our team consists of top-tier developers ready to assist you with your project. If you’re looking to implement Network PID Management in the NS2 tool, our experts are here to help. We offer complete insights into your projects performance to ensure your success.