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Dujovne, Ed. 3 Internet-Draft Universidad Diego Portales 4 Intended status: Informational September 9, 2015 5 Expires: March 12, 2016 7 Deterministic Networks Gap Analysis 8 draft-dujovne-detnet-gap-analysis-01 10 Abstract 12 This document introduces and describes several conditions and use 13 cases where the use of an IP-based layer-3 and up is required to 14 provide a complete networking solution to deterministic networks. 15 The contents of this work is a gap analysis to contribute to the 16 design and development of a number of complimentary modules to 17 provide IP-enabled networking for deterministic networks. 19 Status of This Memo 21 This Internet-Draft is submitted in full conformance with the 22 provisions of BCP 78 and BCP 79. 24 Internet-Drafts are working documents of the Internet Engineering 25 Task Force (IETF). Note that other groups may also distribute 26 working documents as Internet-Drafts. The list of current Internet- 27 Drafts is at http://datatracker.ietf.org/drafts/current/. 29 Internet-Drafts are draft documents valid for a maximum of six months 30 and may be updated, replaced, or obsoleted by other documents at any 31 time. It is inappropriate to use Internet-Drafts as reference 32 material or to cite them other than as "work in progress." 34 This Internet-Draft will expire on March 12, 2016. 36 Copyright Notice 38 Copyright (c) 2015 IETF Trust and the persons identified as the 39 document authors. All rights reserved. 41 This document is subject to BCP 78 and the IETF Trust's Legal 42 Provisions Relating to IETF Documents 43 (http://trustee.ietf.org/license-info) in effect on the date of 44 publication of this document. Please review these documents 45 carefully, as they describe your rights and restrictions with respect 46 to this document. Code Components extracted from this document must 47 include Simplified BSD License text as described in Section 4.e of 48 the Trust Legal Provisions and are provided without warranty as 49 described in the Simplified BSD License. 51 Table of Contents 53 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 54 2. Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 2 55 3. Gap Analysis . . . . . . . . . . . . . . . . . . . . . . . . 3 56 3.1. 6TiSCH Track management . . . . . . . . . . . . . . . . . 3 57 3.2. Deterministic Payload on MPLS . . . . . . . . . . . . . . 3 58 3.3. Traffic Specification implementation for PCE . . . . . . 3 59 3.4. Packet-track ID . . . . . . . . . . . . . . . . . . . . . 3 60 3.5. Packet Redundancy Protocol . . . . . . . . . . . . . . . 4 61 4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4 62 5. Informative References . . . . . . . . . . . . . . . . . . . 4 63 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4 65 1. Introduction 67 The first step to become detnet networks was taken at the stub 68 networks such as 6TiSCH-based ones [I-D.ietf-6tisch-tsch], meaning 69 those simple networks that connect the endpoints to one or several 70 gateways, thus enabling both a predictable delay and a very high 71 reliability. These two characteristics must be preserved along the 72 the multi-hop path between source and destination, thus requiring a 73 fully-fledged deterministic end-to-end network including management 74 services to achieve this goal. This is achieved by installing tracks 75 with all the deterministic capabilities. 77 The evolution towards these kinds of intermediate and backbone 78 deterministic networks has been taken up to the MAC layer by the IEEE 79 by defining several standards to provide building blocks to guarantee 80 a predictable delay, such as buffers, queues and schedulers. The 81 configuration, use, coordination, resources management and control of 82 these blocks must be achieved at a higher layer, tightly linked to 83 the routing scheme. Many applications are currently lacking this 84 kind of solution, forcing bandwidth overprovisioning to reduce packet 85 loss and delay uncertainty. 87 2. Assumptions 89 Current packet loss and delay jitter provided by IP networks are not 90 enough for industrial applications 92 Realtime audio and video for reliable content distribution in local 93 networks is cannot be achieved without time-scheduled IP networks 94 End-to-end delay and packet loss guarantees cannot be provided 95 without a managed deterministic network 97 3. Gap Analysis 99 3.1. 6TiSCH Track management 101 6TiSCH requires the installation of tracks along a path with 102 deterministic capabilities, including scheduled transmissions, 103 intermediate queue management, synchronization and path and packet 104 redundnacy among others. The mechanism to achieve such a path is 105 achieved by using PCE/SDN operations as defined on RFC 7149 106 [RFC7149]. 108 On 6TiSCH, IPv6 packets are carried on installed tracks; to reduce 109 resource usage, there is also the need to forward IPv6 packets by 110 opportunistic reuse of track slots and also reuse link bundle slots 111 to forward schedule packets that missed their track. Both mechanisms 112 require the use of Deterministic Networking managament capabilities. 114 3.2. Deterministic Payload on MPLS 116 There are certain Non-IP protocols such as Profibus and Modbus which 117 can be carried as IPv6 payload as long as this traffic is treated as 118 Deterministic; this can be achieved by the use of MPLS and and a 119 specific mangement module for layer-2 path redundancy, such as 120 Parallel Redundancy Protocol. 122 3.3. Traffic Specification implementation for PCE 124 There are several issues on the implementation of Traffic 125 Specification for the PCE 126 [I-D.ietf-teas-interconnected-te-info-exchange]: 128 A TEAS adaptation to carry the topology (neighbors, link quality, 129 interference test, etc.) and capabilities (buffers, queues and 130 timers) from the point of view of the individual devices. 132 A CCAMP/RSVP-TE adaptation to program the individual tracks 134 An adaptation of PCEP to push an individual device schedule 136 3.4. Packet-track ID 138 Track ID on packets is not defined yet; the use of Diffserv/DSCP and 139 MPLS (and G-MPLS for 6TiSCH) are possible alternatives 141 3.5. Packet Redundancy Protocol 143 There is a need to define a Packet Redundancy Protocol (PRP) for 144 deterministic networks, including the PRP sequence number which can 145 be defined by the ASN. 147 4. Acknowledgments 149 Thanks to the Fondecyt (CONICYT-Chile) 11121475 Project. 151 5. Informative References 153 [I-D.ietf-6tisch-tsch] 154 Watteyne, T., Palattella, M., and L. Grieco, "Using 155 IEEE802.15.4e TSCH in an IoT context: Overview, Problem 156 Statement and Goals", draft-ietf-6tisch-tsch-06 (work in 157 progress), March 2015. 159 [I-D.ietf-teas-interconnected-te-info-exchange] 160 Farrel, A., Drake, J., Bitar, N., Swallow, G., Ceccarelli, 161 D., and X. Zhang, "Problem Statement and Architecture for 162 Information Exchange Between Interconnected Traffic 163 Engineered Networks", draft-ietf-teas-interconnected-te- 164 info-exchange-02 (work in progress), March 2015. 166 [RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined 167 Networking: A Perspective from within a Service Provider 168 Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014, 169 . 171 Author's Address 173 Diego Dujovne (editor) 174 Universidad Diego Portales 175 Escuela de Informatica y Telecomunicaciones 176 Av. Ejercito 441 177 Santiago, Region Metropolitana 178 Chile 180 Phone: +56 (2) 676-8121 181 Email: diego.dujovne@mail.udp.cl