/Flexcomm-Simulator-User-Manual

User Manual for the Flexcomm Simulator

Flexcomm Simulator Documentation

Contents

  1. Configuration Files
    1. Topologies Directory Structure
    2. Files
  2. Runtime Flags
  3. Internal Controller
  4. External Controller
  5. EnergyAPI
  6. SNMP

Configuration files

Directory Structure

The configurations for each topology should be placed inside the topologies folder and follow the following structure:

├── topologies
│   ├── energy-templates.toml
│   ├── topology1
│   │   ├── applications.toml
│   │   ├── configs.toml
│   │   ├── links.toml
│   │   ├── nodes.toml
│   │   ├── flex.json
│   │   ├── flex2.json
│   │   └── estimate.json
│   └── topology2
│       ├── applications.toml
│       ├── configs.toml
│       ├── links.toml
│       ├── nodes.toml
│       ├── flex.json
│       ├── estimate.json
│       ├── estimate2.json
│       └── energy-templates.toml
... 
...

Files

Each topology has its own configuration files:

The top-level energy-templates.toml file applies to all the configurations. However, each topology can also specify a local templates file. In this case, for templates with equal names, the local file overrides the global configuration.

For how to specify different measurement units see Units.

Runtime Flags

Flag Description Default Value
TOPO The topology scenario to simulate example
CHECKSUM If checksums should be calculated false
CONTROLLER Which controller to use (ns3::SimpleController, ns3::SimpleControllerFlex, External, etc...) ns3::SimpleController
OUTPUTS The output path outputs
ESTIFILE The energy estimate file to load estimate.json
FLEXFILE The flexibility file to load flex.json
LINKFAILURES The link failures file to load NONE

Internal Controller

Examples of Internal Controllers are provided with the Flexcomm Simulator (e.g,: ns3::SimpleController). To develop new Internal Controllers refer to Working with custom Controllers.

External Controller

To use an External SDN Controller (e.g.: ryu, onos, etc) with the simulator, the SDN Controller must be running in the localhost at port 6653 before starting the simulation. The simulation can then be launched with the CONTROLLER flag set to External

Note: You may be required to run the simulation with sudo

  • Example: sudo make run CONTROLLER=External
LLDP Notes

Some SDN controllers, like onos, use Link Layer Discovery Protocol (LLDP) by default to survey the network. This is not compatible with the Flexcomm Simulator and such option must be disabled in the Controller to avoid conflicts. To generate a configuration file replacing LLDP and containing the topology characteristics use the switches-config.py script in the utils folder.

EnergyAPI

The EnergyAPI can be used by Internal Controllers to access the energy data provided in the flexibility configuration files using the methods EnergyAPI::GetFlexArrayConsumption(<id/name>) and EnergyAPI::GetEstimateArray(<id/name>)

For External Controllers, an external HTTP server is started on port 5000. Data can be accessed using the endpoints localhost:5000/flex?id=<id/name> and localhost:5000/estimate?id=<id/name>

SNMP

The Flexcomm Simulator provides a simple SNMP implementation so that External Controller can access switches' data using this protocol. To achieve this, if the MibLogger is enabled and an External Controller is in use, an instance of snmpsim is started.

SNMP requests can then be issued to localhost from port 1024 onwards, depending on the number of switches being simulated.

This implementation is intended only to access data, therefore no updates can be made by the controller. For an example of how to create a MIB see MibLogger