Overview
ISO/IEC 21559-1:2022 - "Telecommunications and information exchange between systems - Future network protocols and mechanisms - Part 1: Switching and routing" specifies protocol elements and mechanisms for systems conforming to the Future Network (FN) architecture (see ISO/IEC 21558-1). The standard defines how FN physical and virtual links carry frames and signalling, how flows for audio/video and IT data are handled, and how network synchronization, timing and management are performed across FN deployments.
Key topics
- FN physical links: structure and behavior of physical links that convey sequences of frames, including procedures for negotiating FN operation over legacy physical layers.
- Frame format: mandatory components of an FN frame (including a 4-octet timing field and slots for AV/IT packets) and framing considerations. The timing field encodes time (seconds and nanoseconds) and is compatible with PTP-style timing.
- AV and IT flows: two primary flow types - AV flow for regularly timed media (audio/video, live media) and IT flow for irregular IT traffic - and associated packet/slot handling.
- Link negotiation and establishment: packet formats and state-machine procedures for initiating, accepting, rejecting and managing link establishment and transitions from non-FN to FN frames.
- Virtual links and link management: rules for virtual link creation, error handling and termination within FN systems.
- Network layer synchronization: alignment of frames within islands/clouds, sync domain establishment, link up/down procedures, and signalling messages for sync state and handover.
- Network time: signalling messages and protocols to distribute precise time across FN elements.
- Management of network elements: message formats, status reporting, console data and a Management Information Base (MIB) for call/flow management.
- Implementation guidance: Annex A gives normative guidance for links implemented over 1 Gb/s Ethernet physical layer.
Applications
- Designing and implementing Future Network switching and routing systems that require deterministic media transport, precise timing and robust link negotiation.
- Implementing transport protocols for live audio/video and mixed IT traffic over FN links.
- Integrating FN-capable equipment into heterogeneous environments (e.g., migrating existing Ethernet links to FN frames).
- Developing network element management, MIBs and synchronization services for telecom and media-over-IP products.
Who should use it
- Network architects and protocol designers working on FN-compliant systems
- Telecommunications and broadcast equipment vendors
- System integrators deploying synchronized media transport networks
- Standards bodies and test labs validating FN switching, routing and timing behavior
Related standards (selected)
- ISO/IEC 21558-1 (FN architecture)
- ISO/IEC TR 29181-1 and TR 29181-3 (FN requirements, switching & routing)
- IEC 62379 parts on transmission and signalling
- AES51 (ATM over Ethernet)
Keywords: ISO/IEC 21559-1:2022, Future Network, FN, switching and routing, frame format, AV flow, IT flow, network synchronization, network time, link negotiation, 1GbE, network management.