How to Implement Peer to Peer Topology in NS2

To implement the Peer-to-Peer (P2P) Topology which every nodes (peers) perform both as clients and servers and communicate directly with each other without a centralized server. This kinds of topology is usually used in file-sharing systems, distributed computing environments and decentralized networks. In the simulator NS2 which a Peer-to-Peer topology is executed by connecting the nodes directly to one another also permitting them to swap the data without any hierarchy or central node. We give theoretical procedure to execute this topology in the simulation NS2:

Steps to Implement Peer-to-Peer Topology in NS2:

  1. Set Up the Peer-to-Peer Network Topology:
    • Describe several nodes in which every node can communicate directly including other nodes.
    • Make a duplex links among the nodes that forming direct peer-to-peer connections.
  2. Simulate Traffic Flow:
    • Create a traffic among the nodes that mimicking the peer-to-peer communication.

Example of Peer-to-Peer Topology Implementation in NS2:

The following is a specimen script which establishes how to configure a basic peer-to-peer topology with 5 nodes in which every node are communicates directly with one or more peers:

# Create a new simulator

set ns [new Simulator]

# Open trace file for output

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Define nodes (peers) for the peer-to-peer network

set n0 [$ns node]  ;# Peer node 0

set n1 [$ns node]  ;# Peer node 1

set n2 [$ns node]  ;# Peer node 2

set n3 [$ns node]  ;# Peer node 3

set n4 [$ns node]  ;# Peer node 4

# Create duplex links to form peer-to-peer connections

$ns duplex-link $n0 $n1 1Mb 10ms DropTail  ;# Link between node 0 and node 1

$ns duplex-link $n0 $n2 1Mb 10ms DropTail  ;# Link between node 0 and node 2

$ns duplex-link $n1 $n3 1Mb 10ms DropTail  ;# Link between node 1 and node 3

$ns duplex-link $n2 $n4 1Mb 10ms DropTail  ;# Link between node 2 and node 4

$ns duplex-link $n3 $n4 1Mb 10ms DropTail  ;# Link between node 3 and node 4

# ======= TRAFFIC SIMULATION =======

# Define TCP agents for communication between nodes

# Traffic from node 0 to node 3 (through multiple peers)

set tcp0 [new Agent/TCP]

set sink0 [new Agent/TCPSink]

$ns attach-agent $n0 $tcp0

$ns attach-agent $n3 $sink0

$ns connect $tcp0 $sink0

# Simulate FTP traffic from node 0 to node 3

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ns at 1.0 “$ftp0 start”   ;# Start traffic at 1 second

# Traffic from node 4 to node 1

set tcp1 [new Agent/TCP]

set sink1 [new Agent/TCPSink]

$ns attach-agent $n4 $tcp1

$ns attach-agent $n1 $sink1

$ns connect $tcp1 $sink1

# Simulate FTP traffic from node 4 to node 1

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ns at 2.0 “$ftp1 start”   ;# Start traffic at 2 seconds

# End the simulation after 10 seconds

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

Explanation of the Script:

  1. Nodes (Peers):
    • Nodes n0, n1, n2, n3, and n4 are signify the five nodes (peers) within the peer-to-peer network. Every node can communicate directly with other nodes through the duplex links.
  2. Links:
    • Duplex links are connect the nodes that allowing direct peer-to-peer communication. For instance, the node n0 is connected to n1 and n2, and n3 is connected to n4.
    • These arrangement builds a decentralized structure including the nodes performing both as clients and servers.
  3. Traffic Simulation:
    • TCP agents mimic communication among the nodes.
    • FTP (File Transfer Protocol) produces traffic that replicating file transfers among the nodes.
    • Traffic flows from the node n0 to n3 that may pass over intermediate peers based on the routing and from n4 to n1.
  4. Simulation Duration:
    • For 10 seconds, the simulation runs then allowing the traffic to flow via the peer-to-peer network.

Post-Simulation Analysis:

  1. Trace File Analysis:
    • Here, open the trace file (out.tr) to monitor how packets are sent among the peers. Examine the parameters such as packet delivery, latency, and throughput for communication among the peers.
  2. NAM Visualization:
    • We can use the Network Animator (NAM) to the peer-to-peer topology. We will observe the nodes connected to each other within a decentralized manner and how traffic flows among them.
  3. Performance Metrics:
    • Compute the network performance metrics like delay, throughput, and packet loss to estimate how efficiently the peer-to-peer topology manages the traffic.

Enhancing the Simulation:

  1. Adding More Peers:
    • Append more nodes (peers) to the network and connect them including duplex links to mimic a bigger peer-to-peer network.
  2. Simulating Traffic in Both Directions:
    • Configure extra traffic in both directions such as from n3 to n0 or from n1 to n4 to replicate the bidirectional communication among the peers.
  3. Changing Traffic Type:
    • Swap the TCP with UDP or use CBR (Constant Bit Rate) rather than FTP to emulate various kinds of traffic and examine how the network behaves.
  4. Simulating Node Failures:
    • Replicate the node failures by disconnecting particular nodes or links to monitor how the peer-to-peer network manages these disruptions.
  5. Varying Link Parameters:
    • Test with various link parameters like bandwidth, delay, and queue type such as DropTail or RED to learn how the network performance modifies under several conditions.
  6. Simulating Peer Discovery:
    • In a more difficult peer-to-peer network to execute the peer discovery mechanisms in which nodes actively discover other peers for communication.

We followed a detailed technique, applying and evaluating the Peer-to-Peer topology via the simulation tool NS2. More detailed insights on this topology will also be given, if you required.

To implement the Peer-to-Peer (P2P) Topology ns2project.com will be your best guide as we share you latest ideas and topics. Get network performance analysis done by our developers for your projects.