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Deterministic Networking

Document Charter Deterministic Networking WG (detnet)
Title Deterministic Networking
Last updated 2023-12-01
State Approved
WG State Active
IESG Responsible AD John Scudder
Charter edit AD John Scudder
Send notices to (None)


The Deterministic Networking (DetNet) Working Group focuses on deterministic data paths that operate over Layer 2 bridged and Layer 3 routed segments, where such paths can provide bounds on reordering, latency, loss, and packet delay variation (jitter), and high reliability. DetNet solutions apply to both wireless and wired networks. The Working Group addresses Layer 3 aspects in support of applications requiring deterministic networking. The Working Group collaborates with IEEE802.1 Time-Sensitive Networking (TSN), which is responsible for Layer 2 operations, to define a common architecture for both Layer 2 and Layer 3. Example applications for deterministic networks include professional and home audio/video, multimedia in transportation, engine control systems, and other general industrial and vehicular applications being considered by the IEEE 802.1 TSN Task Group.

The Working Group will initially focus on solutions for networks that are under a single administrative control or within a closed group of administrative control; these include not only campus-wide networks but also private WANs. The DetNet WG will not spend energy on solutions for large groups of domains such as the Internet.

The Working Group is responsible for the overall DetNet architecture and DetNet-specific specifications that encompass the data plane, OAM (Operations, Administration, and Maintenance), time synchronization, management, control, and security aspects which are required to enable a multi-hop path, and forwarding along the path, with the deterministic properties of controlled latency, low packet loss, low packet delay variation, and high reliability. The work applies to point-to-point (unicast) and point-to-multipoint (multicast) flows which can be characterized in a manner that allows the network to 1) reserve the appropriate resources for the flows in advance, and 2) release/reuse the resources when they are no longer required. The work covers the characterization of flows, the encapsulation of frames, the required forwarding behaviors, as well as the state that may need to be established in intermediate nodes. Layer 3 data plane technologies that can be used include: IP and MPLS, and Layer 2 encapsulations that run over IP and/or MPLS, such as pseudowires and GRE.

The Working Group will document which deployment environments and types of topologies are within (or outside) the scope of the DetNet architecture. This work focuses on the data plane aspects and is independent of any path setup protocol or mechanism. The Working Group will also document DetNet Controller Plane approaches that reuse existing IETF solutions, such as Path Computation Element (PCE), and identify the Working Group responsible for any extensions needed to support DetNet. Documents produced by the Working Group will be compatible with the work done in IEEE802.1 TSN and other IETF Working Groups. The Working Group's scope generally excludes modifications of transport protocols, OAM, Layer 3 forwarding, and encapsulations, but it may discuss requirements for such modifications and the work will be coordinated with the Working Group responsible for the technology.

DetNet is chartered to work in the following areas:

Overall architecture: This work encompasses the data plane, OAM, time synchronization, management, control, and security aspects.

Data plane: This work will specify how to use IP and/or MPLS, and related OAM, to support a data plane method of flow identification and packet treatment over Layer 3. Other IETF-defined data plane technologies may also be used.

Controller Plane: The DetNet Controller Plane is defined in RFC 8655 as "the aggregation of the Control and Management Planes". This work will document how to use IETF control plane solutions to support DetNet, including the identification of any gaps in existing solutions. Any modification to Controller Plane protocols to address identified gaps should be carried out in their associated Working Groups, but may be done in DetNet if agreed to by the relevant Working Group chairs and responsible Area Directors.

Data flow information model: This work will identify the information needed for flow establishment and control and be used by reservation protocols and YANG data models. The work will be independent of the protocol(s) used to control the flows (e.g. YANG+NETCONF/RESTCONF, PCEP, or GMPLS).

YANG models: This work will document device and link capabilities (feature support) and resources (e.g. buffers, bandwidth) for use in device configuration and status reporting. Such information may also be used when advertising the deterministic network elements to a control plane. Control plane-related information will be independent of the protocol(s) that may be used to advertise this information (e.g. IS-IS or GMPLS extensions). Any new YANG models will be coordinated with the Working Groups that define any base models that are to be augmented.

DetNets including Wireless: This work will define how DetNet solutions operate over networks that include wired and wireless network technologies. The work may include providing DetNet reliability and availability for scheduled wireless segments and other wireless media, e.g., frequency/time-sharing physical media resources with stochastic traffic: IEEE Std. 802.15.4 timeslotted channel hopping (TSCH), 3GPP 5G ultra-reliable low latency communications (URLLC), IEEE 802.11ax/be, and L-band Digital Aeronautical Communications System (LDACS), etc. This work will stay abstract to the radio layers underneath, addressing the Layer 3 aspects in support of applications requiring high reliability and availability.

As needed, vertical requirements: This effort will detail the requirements for deterministic networks in various industries that have previously not been documented and cannot be supported using defined DetNet solutions.

To investigate whether existing data plane encryption mechanisms can be applied, possibly opportunistically, to improve security and privacy.

The Working Group coordinates with other relevant IETF Working Groups, including CCAMP, IPPM, LSR, PCE, PALS, TEAS, TSVWG, RAW, and 6TiSCH. As the work progresses, requirements may be provided to the responsible Working Group, e.g. PCE, TEAS, and CCAMP, with DetNet acting as a focal point to maintain the consistency of the overall architecture and related solutions. The WG will liaise with appropriate groups in IEEE and other Standards Development Organizations (SDOs).