EchoRequest & EchoResponse

Echo is used to exchange information about latency, bandwidth and liveness. Echo request timeout indicates disconnection. If the OpenFlow implementation is multi-layered, Echo should be implemented in the lowest level (closest to kernel) as it might be used for debugging in some situations.

Initiator: Either
Acknowledged: Yes

Structure

EchoReq in this version has a header and optionally a variable length field, data, containing arbitrary information, such as latency (timestamp), bandwidth, liveness, etc. EchoRes shares the same structure with EchoReq. The EchoRes data is an exact copy of the data present from the corresponding EchoReq.