Overview
ISO/IEC 14908-4:2012 - Information technology - Control network protocol - Part 4: IP communication - specifies how the Control Network Protocol (CNP) is transported over Internet Protocol (IP) networks. The standard defines a tunnelling mechanism in which CNP packets are encapsulated inside IP packets to create an IP channel that behaves as a CNP transport. It applies to both CNP nodes and CNP routers and is intended to ensure interoperability between CNP devices that use IP networks to exchange control messages.
Key topics and technical requirements
The standard focuses on the reliable, efficient transport of CNP over IP. Major technical topics include:
- Tunnelling and encapsulation
- Encapsulation of CNP packets within IP packets to form an IP channel equivalent to other CNP media.
- CNP/IP device behavior
- Requirements for CNP/IP nodes and routers to operate as standard IP hosts and exchange CNP packets across IP subnets or the Internet.
- Message and packet structures
- Definitions for CNP/IP message types, common headers, segmentation, packet formats and sequence handling (see normative packet format sections).
- Ordering, timeout and duplicate detection
- Preserve CNP packet ordering, discard stale packets, and detect duplicated packets introduced by IP transport.
- Performance and scalability
- Efficient operation to support quasi real‑time control traffic and support for prioritized IP routing.
- Configuration and management
- Protocols for interactions with configuration servers, device registration, channel membership, routing updates, and status/health reporting.
- Optional security
- Support for optional authentication and security mechanisms to protect against tampering (security is optional and implementation-dependent).
- Interoperability constraints
- The specification is independent of the higher-level CNP application interface and does not cover lower-layer physical/MAC details or cross‑channel routing logic.
Practical applications - who uses this standard
ISO/IEC 14908-4:2012 is primarily used by manufacturers, integrators and engineers working on commercial local area control networks, including:
- Building automation (HVAC, lighting, access control)
- Facility and energy management systems
- Industrial and commercial control systems that require vendor-neutral CNP interoperability over IP
- Developers of CNP/IP nodes, routers, gateways and configuration servers
Adoption ensures devices from different vendors can communicate reliably over IP while preserving CNP semantics.
Related standards
Note: Implementers should be aware of patent assertions associated with CNP; refer to the standard’s foreword for details.
