To simulate the Routing Information Protocol (RIP) utilizing NS2 (Network Simulator 2) that has valuable exercise to know the distance-vector routing mechanisms and estimate RIP’s performance under numerous network conditions. Even though NS2 does not contain a native execution of RIP, we can be replicated RIP-like behaviour via static routing configurations or by prolonging NS2 with custom scripts. Following is a complete instruction to help us simulate RIP protocol projects using NS2.
Table of Contents
- Understanding RIP and NS2 Compatibility
- Approaches to Simulate RIP in NS2
- Step-by-Step Guide: Simulating RIP using Static Routing
- Advanced Approach: Implementing Custom RIP in NS2
- Alternative: Using NS3 for RIP Simulation
- Evaluation Metrics
- Conclusion
Understanding RIP and NS2 Compatibility
What is RIP?
Routing Information Protocol (RIP) is one of the ancient distance-vector routing protocols, which mainly utilized within small to medium-sized networks. It utilizes hop count as its routing metric, with a maximum allowable hop count of 15, creating it appropriate for less complex networks. RIP periodically transmits its complete routing table to its immediate neighbours that permitting routers to update their routing tables rely on the received information.
NS2’s Native Support for Routing Protocols
NS2 is a discrete event simulator aimed at networking research. It encompasses executions of several routing protocols, primarily concentrated on wireless and ad-hoc networks, like:
- AODV (Ad hoc On-Demand Distance Vector)
- DSR (Dynamic Source Routing)
- OLSR (Optimized Link State Routing)
But, NS2 does not offer a native implementation of RIP. Hence, replicating RIP in NS2 wants either using static routing sets up to approximate RIP behaviour or prolonging NS2 with a custom RIP module.
Approaches to Simulate RIP in NS2
- Static Routing Configuration
One of the simplest techniques to replicate RIP-like behaviour is to manually set up static routes within the network topology. Whereas this method lacks the dynamic nature of RIP (e.g., automatic route updates and adaptability to network changes) then it can help illustrate simple routing concepts and calculate static routing performance.
- Extending NS2 with Custom RIP Implementation
For a more exact simulation, which captures RIP’s dynamic routing aspects, we can improve and incorporate a custom RIP agent into NS2. This method needs a strong understanding of NS2’s internal architecture and C++ programming skills to execute the RIP protocol logic.
Step-by-Step Guide: Simulating RIP using Static Routing
Provided that NS2 does not natively support RIP, we will concentrate on replicating RIP-like behaviour utilizing static routing. This approach includes setting up explicit routes among the nodes to simulate the result of RIP’s routing decisions.
- Install and Set Up NS2
Make certain that NS2 is installed on the machine. We can install NS2 on several platforms, however it is most generally utilized on Linux.
Installation Steps (for Ubuntu/Linux):
sudo apt-get update
sudo apt-get install ns2
Verify the installation:
ns –version
- Define the Network Topology
Make a Tcl script to describe the network topology. For this instance, we will be made a basic network including several nodes are connected in a topology, which could advantage from RIP’s routing capabilities.
Example Topology:
- Nodes: A, B, C, D, E
- Connections:
- A <-> B
- B <-> C
- C <-> D
- D <-> E
- A <-> E (to create a loop for demonstrating routing)
Tcl Script (rip_simulation.tcl):
# Initialize the simulator
set ns [new Simulator]
# Define trace files
set tracefile [open rip_trace.tr w]
$ns trace-all $tracefile
set namfile [open rip.nam w]
$ns namtrace-all-wireless $namfile
# Create nodes
set n0 [$ns node] ;# Node A
set n1 [$ns node] ;# Node B
set n2 [$ns node] ;# Node C
set n3 [$ns node] ;# Node D
set n4 [$ns node] ;# Node E
# Create links (Bidirectional)
$ns duplex-link $n0 $n1 10Mb 10ms DropTail
$ns duplex-link $n1 $n2 10Mb 10ms DropTail
$ns duplex-link $n2 $n3 10Mb 10ms DropTail
$ns duplex-link $n3 $n4 10Mb 10ms DropTail
$ns duplex-link $n0 $n4 10Mb 10ms DropTail
# Assign addresses to nodes (for static routing)
$node_(0) set X_ 0.0
$node_(0) set Y_ 0.0
$node_(1) set X_ 100.0
$node_(1) set Y_ 100.0
$node_(2) set X_ 200.0
$node_(2) set Y_ 200.0
$node_(3) set X_ 300.0
$node_(3) set Y_ 300.0
$node_(4) set X_ 400.0
$node_(4) set Y_ 400.0
- Configure Static Routing to Mimic RIP Behavior
Since RIP dynamically updates routes according to the network topology changes then we will approximate this behaviour by manually setting up static routes, which reflect what RIP might find out in this network.
Static Routing Configuration:
In RIP, each node could have a routing table, which acquires updated periodically. To mimic this, we can describe static routes depends on the topology.
For example:
- Node A:
- Route to C via B
- Route to D via B or E
- Route to E directly
- Node B:
- Route to A directly
- Route to D via C
- Route to E via C
- Node C:
- Route to A via B
- Route to B directly
- Route to E via D
- Node D:
- Route to A via C or E
- Route to B via C
- Route to E directly
- Node E:
- Route to A directly
- Route to B via D or C
- Route to C via D
Executing static routing within NS2 can be done by describing routing tables or by configuring agents with predefined paths.
Adding Static Routing in the Tcl Script:
For simplicity, we will be used TCP connections with predefined paths.
# Create TCP agents and sinks for node A to E communication
set tcp0 [new Agent/TCP]
set sink0 [new Agent/TCPSink]
$ns attach-agent $n0 $tcp0
$ns attach-agent $n4 $sink0
$ns connect $tcp0 $sink0
# Create FTP application to generate traffic
set ftp0 [new Application/FTP]
$ftp0 attach-agent $tcp0
$ftp0 set packetSize_ 500
$ftp0 set interval_ 0.2
# Start FTP at 1.0 seconds and stop at 10.0 seconds
$ns at 1.0 “$ftp0 start”
$ns at 10.0 “$ftp0 stop”
In this configuration, traffic from Node A (n0) to Node E (n4) will pass through the network rely on the static links defined previously. Even though this does not dynamically change to network changes then it serves as a foundation to know the routing behaviours.
- Implement Traffic and Applications
Describe the kinds of traffic and applications we require to mimic. For instance, utilizing FTP or CBR (Constant Bit Rate) traffic can support compute how static routes manage data flow.
Continuing the Tcl Script:
# Additional traffic from Node A to C
set tcp1 [new Agent/TCP]
set sink1 [new Agent/TCPSink]
$ns attach-agent $n0 $tcp1
$ns attach-agent $n2 $sink1
$ns connect $tcp1 $sink1
set ftp1 [new Application/FTP]
$ftp1 attach-agent $tcp1
$ftp1 set packetSize_ 500
$ftp1 set interval_ 0.2
$ns at 2.0 “$ftp1 start”
$ns at 9.0 “$ftp1 stop”
This set up permits to monitor numerous data flows pass through distinct paths in the network.
- Enable Tracing and Monitoring
Tracing is fundamental to observe how packets are routed via the network. The network simulator NS2 offers tracing capabilities, which log packet events that can later be examined to know routing behaviours.
Adding Tracing to the Tcl Script:
# Enable detailed packet tracing
$ns trace-all $tracefile
# Enable NAM tracing for visual representation
$ns namtrace-all-wireless $namfile
Make certain that these lines are involved in the Tcl script to capture all related events.
- Run the Simulation
Implement the Tcl script using NS2 to run the simulation.
ns rip_simulation.tcl
This command will make trace files (rip_trace.tr and rip.nam) that comprise detailed information regarding packet movements and network states for the period of the simulation.
- Analyze the Results
After the simulation finishes then we investigate the trace files to estimate the routing performance.
Analysing Trace Files:
- Packet Flow Analysis:
- Utilize tools such as awk or custom scripts to parse rip_trace.tr and detect how packets pass through the network.
- Verify for parameters such as throughput, delay, and packet loss.
- Visual Analysis with NAM:
- We can open the rip.nam file using the Network Animator (NAM) to visually examine packet flows and routing paths.
nam rip.nam
- Example: Calculating Throughput
We can write an awk script to compute the throughput according to the amount of packets received effectively at the sink nodes.
awk ‘{
if ($4 == “r” && $6 == “tcp” && $7 == “Sink”) {
packets++;
}
} END {
print “Total packets received:”, packets
}’ rip_trace.tr
Save this as throughput.awk and run:
awk -f throughput.awk rip_trace.tr
- Latency Measurement:
Compute the average end-to-end delay by monitoring the time variance among packet transmit and receive events.
Sample awk Script for Delay:
awk ‘{
if ($1 == “s” && $4 == “tcp” && $7 == “A”) {
sent_time[$8] = $2
}
if ($1 == “r” && $4 == “tcp” && $7 == “Sink”) {
if (sent_time[$8]) {
delay = $2 – sent_time[$8]
total_delay += delay
count++
}
}
} END {
if (count > 0) {
print “Average delay:”, total_delay/count, “seconds”
} else {
print “No packets received.”
}
}’ rip_trace.tr
Save as delay.awk and execute:
awk -f delay.awk rip_trace.tr
Summary of Static Routing Simulation
Even though this approach uses static routing, it offers insights into how routing paths influence network performance. To more exactly replicate RIP’s dynamic capabilities, we deliberate executing or prolonging NS2 with a custom RIP module, as detailed in the next section.
Advanced Approach: Implementing Custom RIP in NS2
For an additional authentic simulation of RIP’s dynamic routing aspects, we can improve a custom RIP agent in NS2. This method encompasses changing NS2’s C++ codebase to integrate RIP’s functionalities, like periodic route updates, hop count calculations, and route invalidation.
- Understand NS2’s Routing Architecture
Before executing RIP, familiarize ourselves with NS2’s existing routing protocols and how routing data is propagated and handled in the simulator.
- Routing Protocol Agents: NS2 simulator uses agents to replicate routing protocols. For instance, AODV and DSR are executed as agents, which manage routing logic.
- Routing Tables: Each node conserves a routing table, which is updated according to the routing protocol’s logic.
- Develop a RIP Agent
Make a new RIP agent by prolonging NS2’s existing agent classes. It comprises writing C++ code to manage RIP’s particular behaviors.
Steps:
- Create RIP Agent Class:
- Improve a new C++ class, e.g., Agent/RIP.cc and Agent/RIP.h, which describes the RIP agent’s properties and behaviours.
- Implement RIP Logic:
- Initialization: Configure RIP metrics such as update intervals and metrics.
- Periodic Updates: Execute timers to transmit routing updates at regular intervals (typically every 30 seconds).
- Route Calculation: Manage incoming routing updates, compute hop counts, and update routing tables consequently.
- Route Invalidations: Identify and remove stale routes (e.g., routes that haven’t been updated within a timeout period).
- Integrate with NS2’s Agent Framework:
- Make sure that RIP agent can interface with NS2’s simulation environment, which containing packet handling and event scheduling.
Example: Skeleton of RIP Agent (C++):
#ifndef ns_rip_h
#define ns_rip_h
#include <agent.h>
#include <map>
class RIPAgent : public Agent {
public:
RIPAgent();
void recv(Packet *p, Handler *h);
void sendUpdate();
void processUpdate(Packet *p);
void timeout();
private:
std::map<int, int> routingTable; // Destination node ID -> Hop count
Timer timeoutTimer;
};
#endif
#include “RIP.h”
#include <scheduler.h>
#include <tcp.h>
#include <iostream>
RIPAgent::RIPAgent() : Agent(PT_RIP), timeoutTimer(this) {
// Initialize routing table with direct neighbors
// Example: routingTable[node_id] = hop_count
}
void RIPAgent::recv(Packet *p, Handler *h) {
// Process incoming RIP update
processUpdate(p);
}
void RIPAgent::sendUpdate() {
// Create and send RIP update packets to neighbors
}
void RIPAgent::processUpdate(Packet *p) {
// Extract routing information from the packet and update routingTable
}
void RIPAgent::timeout() {
// Handle periodic update timeout
sendUpdate();
timeoutTimer.resched(30.0); // Reschedule for next update
}
Note: The above code is a simplified skeleton. Executing a complete RIP agent wants handling packet formats, neighbour management, split horizon, and more.
- Integrate the RIP Agent into NS2
After improving the RIP agent then incorporate it into NS2’s build system and make certain it can be invoked from Tcl scripts.
Steps:
- Modify config.status and Makefile.in:
- Insert the RIP agent’s source files to NS2’s build set up thus they are compiled and linked correctly.
- Rebuild NS2:
- After changing the build files then rebuild NS2 to contain the new RIP agent.
cd ns-2.xx
./configure
make clean
make
sudo make install
- Expose RIP Agent to Tcl:
- Make Tcl bindings for the RIP agent thus we can instantiate and set up it within the Tcl simulation scripts.
rip.tcl (Sample Tcl Bindings)
# Define RIP agent type
Agent/RIP set update_interval_ 30.0
- Test and Validate the RIP Implementation
After incorporating the RIP agent then we make test scenarios to authenticate its functionality.
Sample Tcl Script (rip_custom_simulation.tcl):
# Initialize the simulator
set ns [new Simulator]
# Define trace files
set tracefile [open rip_custom_trace.tr w]
$ns trace-all $tracefile
set namfile [open rip_custom.nam w]
$ns namtrace-all-wireless $namfile
# Create nodes
set n0 [$ns node] ;# Node A
set n1 [$ns node] ;# Node B
set n2 [$ns node] ;# Node C
set n3 [$ns node] ;# Node D
set n4 [$ns node] ;# Node E
# Create links (Bidirectional)
$ns duplex-link $n0 $n1 10Mb 10ms DropTail
$ns duplex-link $n1 $n2 10Mb 10ms DropTail
$ns duplex-link $n2 $n3 10Mb 10ms DropTail
$ns duplex-link $n3 $n4 10Mb 10ms DropTail
$ns duplex-link $n0 $n4 10Mb 10ms DropTail
# Install RIP agents on all nodes
set rip0 [new Agent/RIP]
set rip1 [new Agent/RIP]
set rip2 [new Agent/RIP]
set rip3 [new Agent/RIP]
set rip4 [new Agent/RIP]
$ns attach-agent $n0 $rip0
$ns attach-agent $n1 $rip1
$ns attach-agent $n2 $rip2
$ns attach-agent $n3 $rip3
$ns attach-agent $n4 $rip4
# Connect RIP agents to links
$ns connect $rip0 $rip1
$ns connect $rip1 $rip2
$ns connect $rip2 $rip3
$ns connect $rip3 $rip4
$ns connect $rip0 $rip4
# Start RIP periodic updates
$ns at 0.0 “$rip0 sendUpdate”
$ns at 0.0 “$rip1 sendUpdate”
$ns at 0.0 “$rip2 sendUpdate”
$ns at 0.0 “$rip3 sendUpdate”
$ns at 0.0 “$rip4 sendUpdate”
# Implement traffic flows
set tcp0 [new Agent/TCP]
set sink0 [new Agent/TCPSink]
$ns attach-agent $n0 $tcp0
$ns attach-agent $n4 $sink0
$ns connect $tcp0 $sink0
set ftp0 [new Application/FTP]
$ftp0 attach-agent $tcp0
$ftp0 set packetSize_ 500
$ftp0 set interval_ 0.2
$ns at 1.0 “$ftp0 start”
$ns at 10.0 “$ftp0 stop”
# Run the simulation
$ns run
Testing Steps:
- Run the Simulation:
ns rip_custom_simulation.tcl
- Monitor Trace Outputs:
- Verify rip_custom_trace.tr for routing updates, packet forwarding, and potential issues.
- Utilize NAM to envision routing paths:
nam rip_custom.nam
- Validate Routing Tables:
- Make certain that routing tables are being updated appropriately according to the RIP’s logic.
- Check that routes converge and that packets follow the intended paths.
- Debugging:
- If routing does not perform as expected then revisit the RIP agent’s implementation.
- We can be used logging within the RIP agent’s C++ code to trace decision-making processes.
Considerations and Challenges
- Complexity: Executing RIP from scratch needs a deep comprehending of both RIP and NS2’s architecture.
- Testing: Complete testing is essential making sure the RIP agent performs appropriately under several network conditions.
- Maintenance: Custom implementations can make difficulties future upgrades or maintenance of NS2.
Alternative: Using NS3 for RIP Simulation
If executing RIP within NS2 proves very complex or time-consuming then we deliberate using NS3, the successor to NS2 that provides more flexibility and easier integration of custom protocols.
Advantages of NS3:
- Modern Architecture: The simulation environment NS3 is created with modularity in mind that making it easier to execute and incorporate new protocols.
- Active Development: NS3 has an active community and ongoing support that can be helpful for custom implementations.
- Enhanced Features: Enhanced support for IPv6, better models for wireless networks, and more.
Implementing RIP in NS3:
NS3 may still not have a built-in RIP implementation, however its architecture makes easy development of custom routing protocols compared to NS2.
Resources:
- NS3 Official Documentation
- NS3 Tutorials
Evaluation Metrics
When replicating RIP (or RIP-like behavior) within NS2 then we evaluate the following performance parameters to measure the protocol’s effectiveness:
- Throughput:
- Assess the amount of data effectively sent from source to destination.
- Calculate how routing decisions influence data flow efficiency.
- End-to-End Delay:
- Compute the time taken for packets to travel from the origin to the destination.
- Measure the effects of routing paths on latency.
- Packet Delivery Ratio (PDR):
- Identify the ratio of packets received efficiently to those transmitted.
- Detect potential packet losses because of routing issues.
- Routing Overhead:
- Measure the amount of routing updates and manage packets generated.
- Estimate the efficiency of the routing protocol in reducing overhead.
- Convergence Time:
- Assess the time taken for all nodes to have consistent routing tables after a network variation.
- Critical for measuring RIP’s adaptability to network dynamics.
- Hop Count:
- Examine the amount of hops packets take to attain their destinations.
- Compute if RIP’s hop count metric leads to enhance routing paths.
- Scalability:
- Calculate how the routing protocol executes as the network size increases.
- Significant for comprehending RIP’s disadvantages in larger networks.
In this manual, we had comprehensively provided the entire approach to understand the RIP and NS2 Compatibility, Static Routing, implementation of custom RIP, and more utilizing NS2. Also, we offered the alternative procedure for RIP simulation using NS3 and their evaluation metrics that helps you to simulate the RIP protocol projects. We at phdprime.com will be your reliable ally, steering you towards complete success. Our expertise in RIP Protocol Projects simulation using the ns2 tool is specifically designed to support your research needs.
