A first component receives from a second component a set of diagnostic parameters to include in a diagnostic heartbeat packet, and information identifying a data communication protocol to be used for transmitting the diagnostic heartbeat packet. The diagnostic heartbeat packet is a packet comprising a header, a set of heartbeat parameters, and the set of diagnostic parameters. The first component sets a first diagnostic parameter in the set of diagnostic parameters to a first value, the first value being selected to detect a first soft network error condition. A soft network error condition is a network error condition that adversely affects transmission of packets having certain properties in the data communication network. The first component configures the diagnostic heartbeat packet for transmission using the specified data communication protocol and including the set of diagnostic parameters, and sends the diagnostic heartbeat packet to the second component.