To simulate Equal-Cost Multi-Path (ECMP) routing projects within OMNeT++, we will require to leverage the INET framework as a base because it offers most of the essential tools and protocols for routing. ECMP is a routing strategy, which permits data packets to be sent over several paths with the similar cost, and enhancing load distribution through network paths.
Below is a simplified guide to simulate an ECMP routing project using OMNeT++:
Steps to Simulate ECMP Routing Projects in OMNeT++
- Install OMNeT++ and INET Framework
- We can download and install OMNeT++ from here.
- Clone or download the INET framework from INET GitHub repository that contains the essential modules for routing and network simulations.
- Extend INET to Support ECMP
Even though INET offers numerous routing protocols, we may require to execute or expand a routing protocol, which can manage ECMP. We can base it on protocols such as OSPF (Open Shortest Path First) that inherently supports ECMP for routing across equal-cost paths.
ECMP Routing Algorithm:
- ECMP permits utilize of several paths among the source and destination nodes once those paths have the similar cost. The information can be divided across numerous routes to enhance load balancing and redundancy.
- To execute ECMP, we will want to:
- Change the routing table to permit for several next-hop entries with the similar cost.
- Alter the packet forwarding logic to distribute traffic across numerous paths.
- Modify the Routing Table for ECMP
- In INET framework, routing tables are generally managed by protocols such as OSPF or RIP. We will want to expand these to support several next-hop routes for the similar destination.
- Change the RoutingTable.cc file to support numerous next-hop entries for destinations with the same cost.
- Implement ECMP Packet Forwarding
- In the INET framework, packets are sent by the IPv4NetworkLayer. We will want to change this layer to choose one of the obtainable paths for each packet.
- We can execute distinct strategies for forwarding, like:
- Round Robin: Rotate via the available paths.
- Flow-Based: Allocate a flow (e.g., TCP connection) to a particular path.
- Hash-Based: Utilize a hash function (e.g., based on the packet header) to choose a path.
For instance, we might change the IPv4NetworkLayer.cc to utilize a hash-based approach to distribute traffic through equal-cost paths.
- Define the Network Topology (NED File)
- Describe a network topology in which ECMP routing can be utilised. For ECMP to be effective, there should be several paths among specific nodes that have the similar cost.
- We can make a mesh or multi-path topology with numerous routers and hosts, in which each router can forward packets using numerous equal-cost routes.
Example NED file:
network ECMPNetwork {
submodules:
routerA: Router {
@display(“p=100,100”);
}
routerB: Router {
@display(“p=200,100”);
}
routerC: Router {
@display(“p=150,200”);
}
hostA: StandardHost {
@display(“p=50,150”);
}
hostB: StandardHost {
@display(“p=250,150”);
}
connections allowunconnected:
routerA.ethg++ <–> Eth10G <–> routerB.ethg++;
routerA.ethg++ <–> Eth10G <–> routerC.ethg++;
routerB.ethg++ <–> Eth10G <–> routerC.ethg++;
hostA.ethg++ <–> Eth10G <–> routerA.ethg++;
hostB.ethg++ <–> Eth10G <–> routerB.ethg++;
}
- The instance makes a basic mesh with routers A, B, and C, permitting for several equal-cost paths among hostA and hostB.
- Configure ECMP in omnetpp.ini
- Utilize the omnetpp.ini file to set up routing, traffic, and simulation settings.
- We can set up routing protocols like OSPF and configure the routing tables with equal-cost paths.
Example configuration in omnetpp.ini:
[General]
network = ECMPNetwork
**.routingProtocol = “OSPF”
**.ospf.interfaceCost = 10 # Assign equal costs to multiple paths
**.routerA.ospf.isRouter = true
**.routerB.ospf.isRouter = true
**.routerC.ospf.isRouter = true
**.hostA.numApps = 1
**.hostA.app[0].typename = “UdpBasicApp”
**.hostA.app[0].destAddresses = “hostB”
**.hostA.app[0].sendInterval = 0.1s
**.hostA.app[0].messageLength = 1024B
**.hostB.numApps = 1
**.hostB.app[0].typename = “UdpSink”
- This configuration allows OSPF as the routing protocol and allocates equal costs to the interfaces among the routers, successfully permitting ECMP to be utilized.
- hostA is configured to transmit traffic to hostB using a siimple UDP application.
- Run the Simulation
- Now, we can run the simulation from the OMNeT++ IDE. As the network simulation progresses, observes how the traffic from hostA to hostB is distributed across the numerous equal-cost paths.
- We can envision the packet flows and observe how packets are sent along distinct routes.
- Analyze Results
- OMNeT++ offers numerous tools for examining network performance. We can gather and investigate parameters such as:
- Throughput: Estimate how much data is effectively sent.
- Packet delivery ratio: Make certain that the packets are appropriately delivered even when distributed across several paths.
- Load Balancing: Investigate how well the traffic is balanced through the equal-cost paths.
- Latency: Calculate the time it takes for packets to attain their destination when using ECMP.
Utilize OMNeT++’s plove tool to envision scalar data or transfer the outcomes to a tool such as Python for more detailed analysis.
- Extend ECMP Implementation (Optional)
- We can further expand the ECMP by executing more sophisticated load-balancing mechanisms, like adaptive path selection according to the network conditions (e.g., bandwidth, congestion).
- Execute aspects such as path failure recovery, in which the protocol rapidly switches paths if one of the equal-cost paths becomes unobtainable.
Example Structure for ECMP Simulation:
- NED file: Describes network topology, routers, and hosts.
- omnetpp.ini: Includes routing protocol configurations and simulation settings.
- ECMPRouting.cc: If we are executing ECMP from scratch then it would manage the logic for equal-cost path selection and packet forwarding.
At the end, we successfully executed the replicating process to simulate and implement the ECMP routing projects utilizing OMNeT++ simulation tool. If you want further insights on this topic, we will be shared.
We create ECMP Routing Projects with OMNeT++ to fit your needs. Our team uses the INET framework. Stay connected with phdprime.com for top research insights and advice on new topics. Email us for the best simulation support.
