To implement Link Aggregation Control Protocol (LACP) in ns3, we need to create a module that manages link aggregation and distributes traffic across multiple physical links. To combine multiple network connections in parallel to increase throughput and provide redundancy, LACP is used.
Step-by-step guide on implementing LACP in ns3
- Set up your ns3 :
- Make sure that ns3 is installed in the computer. If not, install it.
- Create a New Module for LACP:
- Go to the src directory in ns3 and create a new directory named lacp. Create subdirectories named model, helper, and examples, inside the src directory.
- Define the LACP protocol:
- Create .cc and .h files for the LACP protocol in the model directory. Define the LacpProtocol that simulates the behavior of LACP.
- Implement the LACP class:
- Implement the key components of LACP such as Link Aggregation Groups (LAGs), LACP frames, and the logic to manage aggregated links. For the LACP messages and for logic processes, create classes.
- Integrate the LACP with ns3 network system:
- Modify the NetDevice class or create a custom bridge device that can handle LACP logic. Register LACP as a protocol in ns3.
- Create simulation script:
- Set up a network topology.
- Install the Internet stack.
- Use the LACP helper to enable LACP.
- Set up applications and run the simulation.
Example Code Structure
Below is the example for the implementation of LACP in ns3.
Define LACP Protocol
// src/lacp/model/lacp-protocol.h
#ifndef LACP_PROTOCOL_H
#define LACP_PROTOCOL_H
#include “ns3/packet.h”
#include “ns3/net-device.h”
#include “ns3/timer.h”
#include <vector>
#include <map>
namespace ns3 {
class LacpProtocol : public Object
{
public:
static TypeId GetTypeId (void);
LacpProtocol ();
virtual ~LacpProtocol ();
void Install (Ptr<NetDevice> device);
void ReceiveLacpFrame (Ptr<Packet> packet, Ptr<NetDevice> device);
private:
void Start ();
void Stop ();
void SendLacpFrames ();
void HandleLacpFrame (Ptr<Packet> packet, Ptr<NetDevice> device);
Ptr<NetDevice> m_device;
Timer m_timer;
std::vector<Ptr<NetDevice>> m_lag; // Link Aggregation Group
};
} // namespace ns3
#endif // LACP_PROTOCOL_H
Implement LACP Protocol
// src/lacp/model/lacp-protocol.cc
#include “lacp-protocol.h”
#include “ns3/log.h”
#include “ns3/simulator.h”
#include “ns3/packet.h”
namespace ns3 {
NS_LOG_COMPONENT_DEFINE (“LacpProtocol”);
NS_OBJECT_ENSURE_REGISTERED (LacpProtocol);
TypeId
LacpProtocol::GetTypeId (void)
{
static TypeId tid = TypeId (“ns3::LacpProtocol”)
.SetParent<Object> ()
.SetGroupName (“Network”)
.AddConstructor<LacpProtocol> ();
return tid;
}
LacpProtocol::LacpProtocol ()
{
NS_LOG_FUNCTION (this);
}
LacpProtocol::~LacpProtocol ()
{
NS_LOG_FUNCTION (this);
}
void
LacpProtocol::Install (Ptr<NetDevice> device)
{
NS_LOG_FUNCTION (this << device);
m_device = device;
Start ();
}
void
LacpProtocol::Start ()
{
NS_LOG_FUNCTION (this);
m_timer.SetFunction (&LacpProtocol::SendLacpFrames, this);
m_timer.Schedule (Seconds (1.0));
}
void
LacpProtocol::Stop ()
{
NS_LOG_FUNCTION (this);
m_timer.Cancel ();
}
void
LacpProtocol::SendLacpFrames ()
{
NS_LOG_FUNCTION (this);
// Create LACP frame
Ptr<Packet> packet = Create<Packet> ();
// Add LACP header and information
// …
// Send LACP frame on all links in the LAG
for (auto it = m_lag.begin (); it != m_lag.end (); ++it)
{
Ptr<NetDevice> device = *it;
device->Send (packet->Copy (), device->GetBroadcast (), 0x8809); // Example protocol number for LACP
}
m_timer.Schedule (Seconds (1.0));
}
void
LacpProtocol::ReceiveLacpFrame (Ptr<Packet> packet, Ptr<NetDevice> device)
{
NS_LOG_FUNCTION (this << packet << device);
HandleLacpFrame (packet, device);
}
void
LacpProtocol::HandleLacpFrame (Ptr<Packet> packet, Ptr<NetDevice> device)
{
NS_LOG_FUNCTION (this << packet << device);
// Process LACP frame
// Update LAG based on received LACP frames
// …
}
} // namespace ns3
Helper Class
// src/lacp/helper/lacp-helper.h
#ifndef LACP_HELPER_H
#define LACP_HELPER_H
#include “ns3/net-device-container.h”
#include “ns3/object-factory.h”
#include “ns3/lacp-protocol.h”
namespace ns3 {
class LacpHelper
{
public:
LacpHelper ();
void Install (NodeContainer c) const;
void Install (Ptr<Node> node) const;
void Install (Ptr<NetDevice> device) const;
private:
ObjectFactory m_factory;
};
} // namespace ns3
#endif // LACP_HELPER_H
Implement Helper Class
// src/lacp/helper/lacp-helper.cc
#include “lacp-helper.h”
#include “ns3/lacp-protocol.h”
#include “ns3/node.h”
#include “ns3/ipv4.h”
namespace ns3 {
LacpHelper::LacpHelper ()
{
m_factory.SetTypeId (LacpProtocol::GetTypeId ());
}
void
LacpHelper::Install (NodeContainer c) const
{
for (NodeContainer::Iterator i = c.Begin (); i != c.End (); ++i)
{
Install (*i);
}
}
void
LacpHelper::Install (Ptr<Node> node) const
{
for (uint32_t i = 0; i < node->GetNDevices (); ++i)
{
Ptr<NetDevice> device = node->GetDevice (i);
Install (device);
}
}
void
LacpHelper::Install (Ptr<NetDevice> device) const
{
Ptr<LacpProtocol> protocol = m_factory.Create<LacpProtocol> ();
protocol->Install (device);
}
} // namespace ns3
Example Simulation Script
// examples/lacp-simulation.cc
#include “ns3/core-module.h”
#include “ns3/network-module.h”
#include “ns3/internet-module.h”
#include “ns3/point-to-point-module.h”
#include “ns3/applications-module.h”
#include “ns3/lacp-helper.h”
using namespace ns3;
NS_LOG_COMPONENT_DEFINE (“LacpSimulation”);
int main (int argc, char *argv[])
{
CommandLine cmd;
cmd.Parse (argc, argv);
// Create nodes
NodeContainer nodes;
nodes.Create (4);
// Create point-to-point links
PointToPointHelper p2p;
p2p.SetDeviceAttribute (“DataRate”, StringValue (“1Gbps”));
p2p.SetChannelAttribute (“Delay”, StringValue (“2ms”));
NetDeviceContainer devices01 = p2p.Install (nodes.Get (0), nodes.Get (1));
NetDeviceContainer devices12 = p2p.Install (nodes.Get (1), nodes.Get (2));
NetDeviceContainer devices23 = p2p.Install (nodes.Get (2), nodes.Get (3));
NetDeviceContainer devices30 = p2p.Install (nodes.Get (3), nodes.Get (0));
// Install LACP on all nodes
LacpHelper lacp;
lacp.Install (nodes);
// Install Internet stack
InternetStackHelper internet;
internet.Install (nodes);
// Assign IP addresses
Ipv4AddressHelper address;
address.SetBase (“10.1.1.0”, “255.255.255.0”);
Ipv4InterfaceContainer interfaces01 = address.Assign (devices01);
address.SetBase (“10.1.2.0”, “255.255.255.0”);
Ipv4InterfaceContainer interfaces12 = address.Assign (devices12);
address.SetBase (“10.1.3.0”, “255.255.255.0”);
Ipv4InterfaceContainer interfaces23 = address.Assign (devices23);
address.SetBase (“10.1.4.0”, “255.255.255.0”);
Ipv4InterfaceContainer interfaces30 = address.Assign (devices30);
// Create a packet sink to receive packets
uint16_t sinkPort = 8080;
Address sinkAddress (InetSocketAddress (Ipv4Address (“10.0.0.1”), sinkPort));
PacketSinkHelper packetSinkHelper (“ns3::TcpSocketFactory”, sinkAddress);
ApplicationContainer sinkApps = packetSinkHelper.Install (nodes.Get (0));
sinkApps.Start (Seconds (1.0));
sinkApps.Stop (Seconds (10.0));
// Create a TCP client to send packets
OnOffHelper clientHelper (“ns3::TcpSocketFactory”, sinkAddress);
clientHelper.SetAttribute (“OnTime”, StringValue (“ns3::ConstantRandomVariable[Constant=1]”));
clientHelper.SetAttribute (“OffTime”, StringValue (“ns3::ConstantRandomVariable[Constant=0]”));
clientHelper.SetAttribute (“DataRate”, DataRateValue (DataRate (“1Mbps”)));
clientHelper.SetAttribute (“PacketSize”, UintegerValue (1024));
ApplicationContainer clientApps = clientHelper.Install (nodes.Get (1));
clientApps.Start (Seconds (2.0));
clientApps.Stop (Seconds (10.0));
// Enable tracing
AsciiTraceHelper ascii;
p2p.EnableAsciiAll (ascii.CreateFileStream (“lacp-routing.tr”));
p2p.EnablePcapAll (“lacp-routing”);
// Run the simulation
Simulator::Run ();
Simulator::Destroy ();
return 0;
}
Running the Simulation
To run the simulation, compile the script and execute it:
./waf configure –enable-examples
./waf build
./waf –run lacp-simulation
Overall, we had a complete guide on implementing Link Aggregation Control Protocol (LACP) in ns3 by creating a module that can manage link aggregation and distribute traffic across multiple physical links. Also, we provide more related programming on Link Aggregation Control Protocol (LACP).