All JRDDP packets shall include a variable length header, followed by a variable length payload, followed by a 2-byte CRC Trailer. The figure below shows how the JRDDP packet is embedded within the standard SpaceWire packet. Note that while a SpaceWire packet may have zero or more destination addresses before the JRDDP header, the JRDDP requires that exactly one destination address be delivered to the protocol logic.
"Internal Standards developed by Sandia National Laboratories". Experience Base, Sandia National Laboratories, Albuquerque, NM, 0000.