BS ISO 21080:2016 pdf download

BS ISO 21080:2016 pdf download.Space data and information transfer systems — Licklider transmission protocol (LTP) for CCSDS
block: An array of contiguous octets of application data handed down by the upper layer protocol (typically BP) to be transmitted from one LTP client service instance to another. Any subset of a block comprising contiguous octets beginning at the start of the block is termed a ‘block prefix’, and any such subset of the block ending with the end of the block is termed a ‘block suffix’. red-part: The block prefix that is to be transmitted reliably, i.e., subject to acknowledgment and retransmission. green-part: The block suffix that is to be transmitted unreliably, i.e., not subject to acknowledgments or retransmissions. If present, the green-part of a block begins at the octet following the end of the red-part. session: A thread of LTP protocol activity conducted between two peer engines for the purpose of transmitting a block. Data flow in a session is unidirectional: data traffic flows from the sending peer to the receiving peer, while data-acknowledgment traffic flows from the receiving peer to the sending peer. sender: The data-sending peer of a session. receiver: The data-receiving peer of a session.
client service instance: A software entity, such as an application or a higher-layer protocol implementation, that is using LTP to transfer data. segment: The unit of LTP data transmission activity. It is the data structure transmitted from one LTP engine to another in the course of a session. Each LTP segment is of one of the following types: data segment, report segment, report-acknowledgment segment, cancel segment, cancel-acknowledgment segment. end of block, EOB: The last data segment transmitted as part of the original transmission of a block. This data segment also indicates that the segment’s upper bound is the total length of the block (in octets). end of red-part, EORP: The segment transmitted as part of the original transmission of a block containing the last octet of the block’s red-part. This data segment also indicates that the segment’s upper bound is the length of the block’s red-part (in octets). checkpoint: A data segment soliciting a reception report from the receiving LTP engine. The EORP segment must be flagged as a checkpoint, as must the last segment of any retransmission; these are ‘mandatory checkpoints’. All other checkpoints are ‘discretionary checkpoints’. client service ID: Numeric identifier of the upper-level service to which the segment is to be delivered by the receiver. It is functionally analogous to a TCP port number.