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1. Introduction

This section preserves the RFC text for the RAW architecture, including RAW, DetNet, TSN, OAM, PREOF, PLR, PSE, PCE, PDR, SLA, SLO, SLI, recovery graphs, protection paths, LL API, diagrams, tables, and security considerations.

Original RFC Text​

1.  Introduction

   Deterministic Networking (DetNet) aims to provide bounded latency and
   eliminate congestion loss, even when coexisting with best-effort
   traffic.  It provides the ability to carry specified unicast or
   multicast data flows for real-time applications with extremely low
   packet loss rates and ensures maximum end-to-end delivery latency.  A
   description of the general background and concepts of DetNet can be
   found in [DetNet-ARCH].

   DetNet and the related IEEE 802.1 Time-Sensitive Networking (TSN)
   [TSN] initially focused on wired infrastructure, which provides a
   more stable communication channel than wireless networks.  Wireless
   networks operate on a shared medium where uncontrolled interference,
   including self-induced multipath fading, may cause intermittent
   transmission losses.  Fixed and mobile obstacles and reflectors may
   block or alter the signal, causing transient and unpredictable
   variations of the throughput and Packet Delivery Ratio (PDR) of a
   wireless link.  This adds new dimensions to the statistical effects
   that affect the quality and reliability of the link.

   Nevertheless, deterministic capabilities are required in a number of
   wireless use cases as well [RAW-USE-CASES].  With scheduled radios
   such as Time-Slotted Channel Hopping (TSCH) and Orthogonal Frequency-
   Division Multiple Access (OFDMA) being developed to provide
   determinism over wireless links at the lower layers, providing DetNet
   capabilities has become possible.  See [RAW-TECHNOS] for more on
   TSCH, OFDMA, and other technologies.

   Reliable and Available Wireless (RAW) takes up the challenge of
   providing highly available and reliable end-to-end performances in a
   DetNet network that may include wireless segments.  To achieve this,
   RAW leverages all possible transmission diversity and redundancy to
   ensure packet delivery, while optimizing the use of the shared
   spectrum to preserve bandwidth and save energy.  To that effect, RAW
   defines protection paths that can be activated dynamically upon
   failures and a control loop that dynamically controls the activation
   and deactivation of the feasible protection paths to react quickly to
   intermittent losses.

   The intent of RAW is to meet Service Level Objectives (SLOs) in terms
   of PDR, maximum contiguous losses, or latency boundaries for DetNet
   flows over mixes of wired and wireless networks, including wireless
   access and meshes (see Section 2 for more on the RAW problem).  This
   document introduces and/or leverages terminology (see Section 3),
   principles (see Section 4), and concepts such as protection paths and
   recovery graphs to put together a conceptual model for RAW (see
   Section 5).  Based on that model, this document elaborates on an in-
   network optimization control loop (see Section 6).
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