bool Response = 2; // false if request, true if response
int32 ServiceID = 3; // The service specified for the request
uint32 ClassID = 4; // request only
uint32 InstanceID = 5; // request only
int32 Status = 6; // Response only
repeated uint32 AdditionalStatus = 7; // Response only
bytes Data = 8; // Command data for request, reply data for response
PacketContext Context = 9;