]> ZTE Corporation

No.6 Huashi Park Rd Wuhan Hubei 430223 China xiong.quan@zte.com.cn

CAICT

China zhaojunfeng@caict.ac.cn

Cisco Systems, Inc.

Canada rgandhi@cisco.com

Routing DETNET The DetNet data fields defined in Deterministic Latency Action (DLA) can be used in enhanced Deterministic Networking (DetNet) to provide QoS treatment to achieve deterministic latency. This document defines how DetNet data fields are encapsulated in IPv6 option.

Introduction According to , Deterministic Networking (DetNet) operates at the IP layer and delivers service which provides extremely low data loss rates and bounded latency within a network domain. DetNet data planes has been specified in . The existing deterministic technologies are facing large-scale number of nodes and long-distance transmission, traffic scheduling, dynamic flows, and other controversial issues in large-scale networks. The enhanced DetNet Data plane is required to support a data plane method of flow identification and packet treatment. has described the enhancement requirements for DetNet data plane, it is required to support information used by functions ensuring Deterministic Latency. has proposed the overall framework of DetNet enhancements for large-scale deterministic networks. The packet treatment should schedule the resources and indicate the behaviour to ensure the deterministic latency. Moreover, new functions and related metadata should be supported in enhanced DetNet. has proposed a common DetNet data fields and option types for enhanced DetNet data plane and defined a Deterministic Latency Action (DLA) option to carry queuing-based metadata. This document defines how DetNet data fields are encapsulated in IPv6 option such as Deterministic Latency Action (DLA) data fields.

Conventions used in this document

Terminology The terminology is defined as .

Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

The DetNet Options has proposed a common DetNet data fields and option types for enhanced DetNet data plane. This document defines new IPv6 options for DetNet to signal DetNet data fields. The DetNet options helps to discriminate the types of mechanisms and specify the related parameters. The format of the DetNet options follow the generic definition in section 4.2 of . The DetNet options may be placed either in an HbH or a DoH EH. Multiple options with the same option type MAY appear in the same hop-by-hop options or destination options header with distinct data.

DetNet Options Format

has defined a Deterministic Latency Action (DLA) option to carry queuing-based metadata. The DetNet DLA option data can be provided as follows: Option Type: TBD1, 8-bit option type identifier indicates the DetNet Options. Opt Data Len: 8-bit unsigned integer. Length of this option, in octets, not including the first 2 octets. Reserved: 8-bit field MUST be set to zero. DetNet-Length: 16-bit field indicates the DetNet option length. DetNet-Type: 16-bit field indicates the DetNet option type. DetNet Options Data: Variable-length field and Option-Type-specific data. has defined a Deterministic Latency Action (DLA) option to carry queuing-based metadata. The DetNet option data can be provided as follows:

DetNet DLA Option Format

The definition of the value can be referred as . The DetNet option data and Ancillary data can be provided one time or in list.

Encapsulation of DetNet Options

IPv6 Networks The DetNet Options is intended to be placed in an IPv6 HbH EH since it must be processed by every DetNet forwarding node along the path. For the DetNet DLA option, all DetNet forwarding nodes can use the queuing information to achieve the packet forwarding and scheduling. The format of DetNet DLA option in IPv6 is as follows.

DetNet DLA Option Format in IPv6

SRv6 Networks The DetNet Options is intended to be placed in an DOH EH before an SRH since it must be processed by the DetNet forwarding nodes of the SRv6 segment list. For the DetNet DLA option, the DetNet forwarding nodes among SRv6 segment list can use the queuing-based information to achieve the packet forwarding and scheduling. The format of DetNet DLA option in SRv6 is as follows.

DetNet DLA Option Format in SRv6

Security Considerations TBA

IANA Considerations

New Option for IPv6 This specification updates the "Destination Options and Hop-by-Hop Options" under the "Internet Protocol Version 6 (IPv6) Parameters" registry with the values below:

Type	Description	Reference
TBD1	DetNet DLA Option	[this document]

Acknowledgements The authors would like to thank Aihua Liu, Peng Liu, Bin Tan, Shaofu Peng for their review, suggestions and comments to this document.

Normative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. This memo describes the network element behavior required to deliver a guaranteed service (guaranteed delay and bandwidth) in the Internet. [STANDARDS-TRACK] This document provides the overall architecture for Deterministic Networking (DetNet), which provides a capability to carry specified unicast or multicast data flows for real-time applications with extremely low data loss rates and bounded latency within a network domain. Techniques used include 1) reserving data-plane resources for individual (or aggregated) DetNet flows in some or all of the intermediate nodes along the path of the flow, 2) providing explicit routes for DetNet flows that do not immediately change with the network topology, and 3) distributing data from DetNet flow packets over time and/or space to ensure delivery of each packet's data in spite of the loss of a path. DetNet operates at the IP layer and delivers service over lower-layer technologies such as MPLS and Time- Sensitive Networking (TSN) as defined by IEEE 802.1. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. This document provides an overall framework for the Deterministic Networking (DetNet) data plane. China Mobile Huawei Futurewei Technologies USA ZTE Corporation ETRI Aiming at the large-scale deterministic network, this document describes the technical and operational requirements when the different deterministic levels of applications co-exist and are transported over a wide area. This document also describes the corresponding Deterministic Networking (DetNet) data plane enhancement requirements. ZTE Corporation China Mobile This document describes enhancements to DetNet to achieve the differentiated DetNet QoS in large-scale deterministic networks including the overall requirements and solutions with deterministic resources, routes and services. Huawei Technologies Co. Ltd EPFL EPFL Huawei Technologies Co. Ltd Ericsson This document presents a timing model for sources, destinations, and DetNet transit nodes. Using the model, it provides a methodology to compute end-to-end latency and backlog bounds for various queuing methods. The methodology can be used by the management and control planes and by resource reservation algorithms to provide bounded latency and zero congestion loss for the DetNet service. Huawei Huawei This document presents a queuing mechanism with multiple cyclic buffers. RAD Routers perform two distinct user-plane functionalities, namely forwarding (where the packet should be sent) and scheduling (when the packet should be sent). One forwarding paradigm is segment routing, in which forwarding instructions are encoded in the packet in a stack data structure, rather than programmed into the routers. Time Sensitive Networking and Deterministic Networking provide several mechanisms for scheduling under the assumption that routers are time synchronized. The most effective mechanisms for delay minimization involve per-flow resource allocation. SRTSN is a unified approach to forwarding and scheduling that uses a single stack data structure. Each stack entry consists of a forwarding portion (e.g., IP addresses or suffixes) and a scheduling portion (deadline by which the packet must exit the router). SRTSN thus fully implements network programming for time sensitive flows, by prescribing to each router both to-where and by-when each packet should be sent. ZTE Corporation ZTE Corporation China Mobile This document describes a deterministic forwarding mechanism based on deadline. The mechanism enhances strict priority scheduling algorithm with dynamically adjusting the priority of the queue according to its deadline attribute. ZTE Corporation ZTE Corporation This document introduces new IPv6 options for Hop-by-Hop Options header, to carry deadline related information for deterministic flows. Sangmyung University ETRI ETRI Huawei China Mobile This document describes an overall framework of Asynchronous Deterministic Networking (ADN) for large-scale networks. It specifies the functional architecture and requirements for providing latency and jitter bounds to high priority traffic, without time- synchronization of network nodes. This document specifies version 6 of the Internet Protocol (IPv6). It obsoletes RFC 2460. This document discusses the specific metadata which should be carried in Enhanced Data plane (EDP), proposes the DetNet data fields and option types for EDP such as Deterministic Latency Action Option. DetNet Data-Fields for EDP can be encapsulated into a variety of protocols such as MPLS, IPv6 and SRv6 networks.