ISO 20217:2015 pdf free download.Space data and information transfer systems一Spacecraft onboard interface services一File and packet store services.
1.5.2.2 Terms defined in this Recommended Practice
For the purposes of this Recommended Practice, the following definitions also apply:
application: Any component of the onboard software that makes use of the File and Packet Store Services. This includes flight software applications and higher-layer services.
file: An ordered collection of arbitrary in )rmation, or resource for storing information, residing in some kind of durable storage, and with an associated name.
file system: A method of storing and organizing files and the data they contain to make it easy to find and access them. File systems may use a local data storage device or provide access to data on a remote server over a network. Optionally, there may be a hierarchy of files, i.e., a folder or directory tree.
file store: A file system and its storage media. A file store comprises:
— one or more mass niemories in which files reside;
— an associated file system providing services for managing the files stored in the mass memories. This document does not intend to define a file system; it is therefore assumed that a file system interfacing to one or more mass memories is already present.
NOTE — No assumption is made about persistence of’ files in the file store or any file replication strategies.
packet: At a minimum level of complexity, a delimited data structure. Examples of’ such packets are CCSDS Space Packets (reference 1D4]), CCSDS Encapsulation Packets (reference [D5]), IPv4 (reference [D6]) and IPv6 (reference [D7]) packets. Packets are time- stamped with the time the packet was stored in the packet store. For CCSDS packets. primary header fields are accessible to the PSAS. These include packet idenüfiers and protocol identifiers.
packet store: A collection of packets and its storage media. A packet store comprises:
— one or more mass memories in which packets reside;
— an associated packet storage system providing services for managing the packets stored in the mass memories.
NOTES
I No assumption is made about persistence of packets in the packet store or any replication strategies.
2 No assumption is made about where the packet store is located (remotely or locally).ISO 20217 pdf download.