If the request is so badly constructed that the PPG cannot identify the kind of request it represents, or if the version of the protocol is not supported, the PPG sends back to the Push Initiator a bad message response.

The status code is either 2000, meaning a bad request, or 3002, meaning that the version is not supported.

The bad message response might contain a fragment of the unrecognizable message in the bad-message-fragment attribute.