ISO 21323:2016 PDF

Overview

ISO 21323:2016 - Space data and information transfer systems - CCSDS Bundle protocol specification - standardizes the CCSDS Bundle Protocol (BP) for Delay‑Tolerant Networking (DTN) in space. It defines an end‑to‑end network layer service for exchanging messages (“bundles”) across networks with long latency, intermittent connectivity, or temporary partitions. The standard adapts RFC 5050 for space use and is intended as a uniform Recommended Standard across CCSDS member agencies. ISO 21323:2016 is transport‑agnostic and is usable over AOS, Space Packet, Proximity‑1, internet and ground protocols.

Key topics and requirements

• End‑to‑end bundle service: Defines BP message formats, abstract service descriptions, and primitives to send/receive bundles in DTN environments.
• Custody‑based retransmission: Supports custody transfer to provide reliable delivery when links are unreliable or scheduled.
• Intermittent and opportunistic connectivity: Designed to exploit scheduled, predicted, and opportunistic contacts in addition to continuous links.
• Data accountability and reporting: Built‑in status reporting and notional accountability for transferred data.
• Convergence Layer Adapters (CLAs): BP is agnostic to underlying transport; Annex B describes CLAs to map BP to specific link protocols.
• Conformance and implementation: Section 6 and Annex A provide conformance requirements and a Protocol Implementation Conformance Statement (PICS) proforma.
• Extensions and ancillary specs: Normative annexes cover Extended Class of Service, Aggregate Custody Signals, Delay‑Tolerant Payload Conditioning, BP managed information, and security/SANA/patent considerations.

Applications

ISO 21323:2016 is targeted at any space mission or infrastructure that is communication‑resource poor or subject to long latencies and network partitions. Typical use cases:

• Deep‑space missions and planetary probes where long light‑time delays occur.
• Lunar and interplanetary relays with scheduled contacts.
• Satellite constellations and remote sensing platforms with intermittent ground passes.
• Onboard spacecraft networking where internode links are disrupted or scheduled.
• Ground‑to‑space data transfer systems requiring reliable delivery over disrupted links.

Who uses this standard

• Space agencies and mission architects (NASA, ESA, JAXA, etc.)
• Satellite and spacecraft systems engineers and network architects
• Communications and ground‑station integrators
• Space networking software developers and vendors implementing DTN/CCSDS BP stacks
• Standards and interoperability teams validating conformance across agencies

Related standards

• RFC 5050 - Bundle Protocol (baseline DTN specification)
• CCSDS Recommended Standards (as CCSDS 734.2‑B‑1 / ISO adoption) ISO 21323:2016 codifies the CCSDS profile of RFC 5050 and provides space‑specific guidance, conformance rules, and normative extensions for operational DTN deployments.