--- 1/draft-ietf-detnet-problem-statement-03.txt 2018-06-06 06:13:27.963781682 -0700 +++ 2/draft-ietf-detnet-problem-statement-04.txt 2018-06-06 06:13:27.987782250 -0700 @@ -1,19 +1,19 @@ detnet N. Finn Internet-Draft Huawei Technologies Co. Ltd Intended status: Informational P. Thubert -Expires: September 19, 2018 Cisco - March 18, 2018 +Expires: December 8, 2018 Cisco + June 6, 2018 Deterministic Networking Problem Statement - draft-ietf-detnet-problem-statement-03 + draft-ietf-detnet-problem-statement-04 Abstract This paper documents the needs in various industries to establish multi-hop paths for characterized flows with deterministic properties . Status of This Memo This Internet-Draft is submitted in full conformance with the @@ -22,21 +22,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on September 19, 2018. + This Internet-Draft will expire on December 8, 2018. Copyright Notice Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -53,21 +53,21 @@ 3. Problem Statement . . . . . . . . . . . . . . . . . . . . . . 6 3.1. Supported topologies . . . . . . . . . . . . . . . . . . 6 3.2. Flow Characterization . . . . . . . . . . . . . . . . . . 6 3.3. Centralized Path Computation and Installation . . . . . . 6 3.4. Distributed Path Setup . . . . . . . . . . . . . . . . . 7 3.5. Duplicated data format . . . . . . . . . . . . . . . . . 8 4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 6. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 7. Informative References . . . . . . . . . . . . . . . . . . . 9 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 1. Introduction The Deterministic Networking Use Cases [I-D.ietf-detnet-use-cases] document illustrates that beyond the classical case of industrial automation and control systems (IACS), there are in fact multiple industries with strong and yet relatively similar needs for deterministic network services with latency guarantees and ultra-low packet loss. @@ -137,36 +137,37 @@ dramatically over the last 30-40 years. Video and audio entertainment, and control systems for machinery, manufacturing processes, and vehicles are also ubiquitous, and are now based almost entirely on digital technologies. Over the past 10 years, engineers in these fields have come to realize that significant advantages in both cost and in the ability to accelerate growth can be obtained by basing all of these disparate digital technologies on packet networks. The goals of Deterministic Networking are to enable the migration of - applications that use special-purpose fieldbus technologies (HDMI, - CANbus, ProfiBus, etc... even RS-232!) to packet technologies in - general, and the Internet Protocol in particular, and to support both - these new applications, and existing packet network applications, - over the same physical network. + applications with critical timing and reliability issues that + currently use special-purpose fieldbus technologies (HDMI, CANbus, + ProfiBus, etc... even RS-232!) to packet technologies in general, and + the Internet Protocol in particular, and to support both these new + applications, and existing packet network applications, over the same + physical network. Considerable experience ([ODVA]/[EIP],[AVnu], [Profinet],[HART],[IEC62439], [ISA100.11a] and [WirelessHART], etc...) has shown that these applications need a some or all of a suite of features that includes: 1. Time synchronization of all host and network nodes (routers and/ or bridges), accurate to something between 10 nanoseconds and 10 microseconds, depending on the application. - 2. Support for critical packet flows that: + 2. Support for Deterministic packet flows that: * Can be unicast or multicast; * Need absolute guarantees of minimum and maximum latency end- to-end across the network; sometimes a tight jitter is required as well; * Need a packet loss ratio beyond the classical range for a particular medium, in the range of 10^-9 to 10^-12, or better, on Ethernet, and in the order of 10^-5 in Wireless Sensor Mesh @@ -248,21 +249,21 @@ On the other end, the deterministic portion of a path may be a tunnel between and ingress and an egress router. In any case, routers and switches in between should not need to be aware whether the path is end-to-end of a tunnel. While it is clear that DetNet does not aim at setting up deterministic paths over the global Internet, there is still a lack of clarity on the limits of a domain where a deterministic path can be set up. These limits may depend in the technology that is used to - seu th epath up, whether it is centralized or distributed. + set the path up, whether it is centralized or distributed. 3.2. Flow Characterization Deterministic forwarding can only apply on flows with well-defined characteristics such as periodicity and burstiness. Before a path can be established to serve them, the expression of those characteristics, and how the network can serve them, for instance in shaping and forwarding operations, must be specified. 3.3. Centralized Path Computation and Installation @@ -318,23 +319,28 @@ To enable a RSVP-TE like functionality, the following steps would take place: 1. Neighbors and their capabilities are discovered and exposed to compute a path that fits the DetNet constraints, typically of latency, time precision and resource availability. 2. A constrained path is calculated with an improved version of CSPF that is aware of DetNet. - 3. The path is installed using RSVP-TE, associated with flow - identification, per-hop behavior such as replication and - elimination, blocked resources, and flow timing information. + 3. The path may be installed using a control protocol such as RSVP- + TE, associated with flow identification, per-hop behavior such as + Packet Replication and Elimination, blocked resources, and flow + timing information. Alternatively, the routing and flow + information may be placed in-band in the packet, e.g., using + Segment Routing, in which case the packet is routed along a + prescribed source route path following forwarding indications + that are present in the packet. 4. Traffic flows are transported through the MPLS-TE tunnel, using the reserved resources for this flow at each hop. 3.5. Duplicated data format In some cases the duplication and elimination of packets over non- congruent paths is required to achieve a sufficiently high delivery ratio to meet application needs. In these cases, a small number of packet formats and supporting protocols are required (preferably, @@ -362,26 +368,25 @@ resources such as Ethernet trunks and radio spectrum. The requirement is that there is no possible data leak from and into a deterministic flow, and in a more general fashion there is no possible influence whatsoever from the outside on a deterministic flow. The expectation is that physical resources are effectively associated with a given flow at a given point of time. In that model, Time Sharing of physical resources becomes transparent to the individual flows which have no clue whether the resources are used by other flows at other times. - Security must cover: + The overall security of a deterministic system must cover: o the protection of the signaling protocol o the authentication and authorization of the controlling nodes - o the identification and shaping of the flows o the isolation of flows from leakage and other influences from any activity sharing physical resources. 5. IANA Considerations This document does not require an action from IANA. 6. Acknowledgments @@ -379,26 +384,27 @@ o the isolation of flows from leakage and other influences from any activity sharing physical resources. 5. IANA Considerations This document does not require an action from IANA. 6. Acknowledgments - The authors wish to thank Lou Berger, Jouni Korhonen, Erik Nordmark, - George Swallow, Rudy Klecka, Anca Zamfir, David Black, Thomas - Watteyne, Shitanshu Shah, Craig Gunther, Rodney Cummings, Wilfried - Steiner, Marcel Kiessling, Karl Weber, Ethan Grossman, Patrick - Wetterwald, Subha Dhesikan, Rudy Klecka and Pat Thaler for their - various contribution to this work. + The authors wish to thank Lou Berger, Stewart Bryant, Janos Farkas, + Andrew Malis, Jouni Korhonen, Erik Nordmark, George Swallow, Rudy + Klecka, Anca Zamfir, David Black, Thomas Watteyne, Shitanshu Shah, + Kiran Makhijani, Craig Gunther, Rodney Cummings, Wilfried Steiner, + Marcel Kiessling, Karl Weber, Ethan Grossman, Patrick Wetterwald, + Subha Dhesikan, Rudy Klecka and Pat Thaler for their various + contributions to this work. 7. Informative References [AVnu] http://www.avnu.org/, "The AVnu Alliance tests and certifies devices for interoperability, providing a simple and reliable networking solution for AV network implementation based on the IEEE Audio Video Bridging (AVB) and Time-Sensitive Networking (TSN) standards.". [EIP] http://www.odva.org/, "EtherNet/IP provides users with the @@ -409,22 +415,21 @@ . [HART] www.hartcomm.org, "Highway Addressable Remote Transducer, a group of specifications for industrial process and control devices administered by the HART Foundation". [I-D.ietf-detnet-use-cases] Grossman, E., "Deterministic Networking Use Cases", draft- - ietf-detnet-use-cases-14 (work in progress), February - 2018. + ietf-detnet-use-cases-16 (work in progress), May 2018. [IEC62439] IEC, "Industrial communication networks - High availability automation networks - Part 3: Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR) - IEC62439-3", 2012, . [IEEE802.1TSNTG] IEEE Standards Association, "IEEE 802.1 Time-Sensitive