705x2b1s - CCSDS

CCSDS HISTORICAL DOCUMENTRECOMMENDATION FOR ADVANCED ORBITING SYSTEMS2.3.1 PacketConstruction ProcessThis process accepts primitives on the [pkt] and [oct] gate, constructing packets in the case of theOctetString service, or checking their format in the case of the UserFormatted service. Thesepackets are passed through the [int] gate along with the PathID to be relayed onwards asnecessary.The process is passed five parameters:PathServiceTypePathIDSequenceCountpacketTypemaxSDULengthdetermines which gate the process will accept primitives on.the PathID (i.e., SAP) to accept primitives on.used only by the OctetString service, this is updated witheach Packet sent, the initial value being set by management.the value to be placed into the Packet Type field of Packetsconstructed on the OctetString service.the maximum length for SDUs on this Path; taken to belength of OctetString for the OctetString service, or totallength of Packet for UserFormatted service.The variable called ‘Data’ at the [oct] gate refers to the O_SDU which is part of theOCTET_STRING.request primitive.CCSDS 705.2-B-1 Page 2-13 May 1994CCSDS HISTORICAL DOCUMENT