Match-Action engines are a combination of Look-up engines and Action engines. Multiple actions are mapped, or activated, by the response of a Look-up engine. The Look-up engine response is used to enable only one action engine and store parameters required by the action.
Match-Action engines perform the following sequence of operations:
- Constructing look-up keys from user defined metadata
- Table look-up using the constructed key and returning a response
- Choosing an action and executing it based on the above response
- Performing programmed computations and returning an output
- Interfacing to/from user externs
An example of a simple Match-Action engine is provided in Sample P416 Program.