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Versions: 00

DetNet                                                  J. Korhonen, Ed.
Internet-Draft
Intended status: Standards Track                           B. Varga, Ed.
Expires: January 1, 2019                                        Ericsson
                                                           June 30, 2018


                   DetNet IP Data Plane Encapsulation
                     draft-ietf-detnet-dp-sol-ip-00

Abstract

   This document specifies Deterministic Networking data plane operation
   for IP encapsulated user data.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   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 January 1, 2019.

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
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.





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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Terms used in this document . . . . . . . . . . . . . . .   3
     2.2.  Abbreviations . . . . . . . . . . . . . . . . . . . . . .   3
     2.3.  Requirements language . . . . . . . . . . . . . . . . . .   4
   3.  DetNet IP Data Plane Overview . . . . . . . . . . . . . . . .   4
     3.1.  DetNet IP Flow Identification . . . . . . . . . . . . . .   7
     3.2.  DetNet Data Plane Requirements  . . . . . . . . . . . . .   8
   4.  DetNet IP Data Plane Considerations . . . . . . . . . . . . .   8
     4.1.  End-system specific considerations  . . . . . . . . . . .   9
     4.2.  DetNet domain specific considerations . . . . . . . . . .  10
       4.2.1.  DetNet Routers  . . . . . . . . . . . . . . . . . . .  11
     4.3.  Networks with multiple technology segments  . . . . . . .  12
     4.4.  OAM . . . . . . . . . . . . . . . . . . . . . . . . . . .  12
     4.5.  Class of Service  . . . . . . . . . . . . . . . . . . . .  12
     4.6.  Quality of Service  . . . . . . . . . . . . . . . . . . .  13
     4.7.  Cross-DetNet flow resource aggregation  . . . . . . . . .  14
     4.8.  Time synchronization  . . . . . . . . . . . . . . . . . .  15
   5.  Management and control plane considerations . . . . . . . . .  15
     5.1.  Explicit routes . . . . . . . . . . . . . . . . . . . . .  16
     5.2.  Service protection  . . . . . . . . . . . . . . . . . . .  16
     5.3.  Congestion protection and latency control . . . . . . . .  16
     5.4.  Flow aggregation control  . . . . . . . . . . . . . . . .  16
     5.5.  Bidirectional traffic . . . . . . . . . . . . . . . . . .  16
   6.  DetNet IP Encapsulation Procedures  . . . . . . . . . . . . .  17
     6.1.  Multi-Path Considerations . . . . . . . . . . . . . . . .  17
   7.  Mapping IP DetNet Flows to IEEE 802.1 TSN . . . . . . . . . .  17
     7.1.  TSN Stream ID Mapping . . . . . . . . . . . . . . . . . .  18
     7.2.  TSN Usage of FRER . . . . . . . . . . . . . . . . . . . .  18
     7.3.  Management and Control Implications . . . . . . . . . . .  18
   8.  Security considerations . . . . . . . . . . . . . . . . . . .  18
   9.  IANA considerations . . . . . . . . . . . . . . . . . . . . .  18
   10. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  18
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  19
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  20
     12.1.  Normative references . . . . . . . . . . . . . . . . . .  20
     12.2.  Informative references . . . . . . . . . . . . . . . . .  22
   Appendix A.  Example of DetNet data plane operation . . . . . . .  24
   Appendix B.  Example of pinned paths using IPv6 . . . . . . . . .  24
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  24

1.  Introduction

   Deterministic Networking (DetNet) is a service that can be offered by
   a network to DetNet flows.  DetNet provides these flows extremely low
   packet loss rates and assured maximum end-to-end delivery latency.



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   General background and concepts of DetNet can be found in the DetNet
   Architecture [I-D.ietf-detnet-architecture].

   This document specifies the DetNet data plane operation for IP hosts
   and routers that provide DetNet service to IP encapsulated data.  No
   DetNet specific encapsulation is defined to support IP flows, rather
   existing IP header information is used to support flow identification
   and DetNet service delivery.  General background on the use of IP
   headers, and "5-tuples", to identify flows and support Quality of
   Service (QoS) can be found in [RFC3670].  [RFC7657] also provides
   useful background on the delivery differentiated services (DiffServ)
   and "6-tuple" based flow identification.

   The DetNet Architecture decomposes the DetNet related data plane
   functions into two layers: a service layer and a transport layer.
   The service layer is used to provide DetNet service protection and
   reordering.  The transport layer is used to provides congestion
   protection (low loss, assured latency, and limited reordering).  As
   no DetNet specific headers are added to support IP DetNet flows, only
   the transport layer functions are supported using the IP DetNet
   defined by this document.  Service protection can be provided on a
   per sub-net basis using technologies such as MPLS
   [I-D.ietf-detnet-dp-sol-mpls] and IEEE802.1 TSN.

   This document provides an overview of the DetNet IP data plane in
   Section 3, considerations that apply to providing DetNet services via
   the DetNet IP data plane in Section 4 and Section 5.  Section 6
   provides the requirements for hosts and routers that support IP-based
   DetNet services.  Finally, Section 7 provides rules for mapping IP-
   based DetNet flows to IEEE 802.1 TSN streams.

2.  Terminology

2.1.  Terms used in this document

   This document uses the terminology and concepts established in the
   DetNet architecture [I-D.ietf-detnet-architecture] the reader is
   assumed to be familiar with that document.

2.2.  Abbreviations

   The following abbreviations used in this document:

   CE            Customer Edge equipment.

   CoS           Class of Service.

   DetNet        Deterministic Networking.



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   DF            DetNet Flow.

   L2            Layer-2.

   L3            Layer-3.

   LSP           Label-switched path.

   MPLS          Multiprotocol Label Switching.

   OAM           Operations, Administration, and Maintenance.

   PE            Provider Edge.

   PREOF         Packet Replication, Ordering and Elimination Function.

   PSN           Packet Switched Network.

   PW            Pseudowire.

   QoS           Quality of Service.

   TE            Traffic Engineering.

   TSN           Time-Sensitive Networking, TSN is a Task Group of the
                 IEEE 802.1 Working Group.

2.3.  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 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  DetNet IP Data Plane Overview

   This document describes how IP is used by DetNet nodes, i.e., hosts
   and routers, to identify DetNet flows and provide a DetNet service.
   From a data plane perspective, an end-to-end IP model is followed.











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   IP  DetNet       Relay                        Relay       IP DetNet
   End System       Node                         Node        End System

   +---------+                                               +---------+
   |  Appl.  |<--------------- End to End Service ---------->|  Appl.  |
   +---------+    ...........                  ...........   +---------+
   | Service |<---: Service :-- DetNet flow ---: Service :-->| Service |
   +---------+    +---------+                  +---------+   +---------+
   |Transport|    |Transport|                  |Transport|   |Transport|
   +-------.-+    +-.-----.-+                  +-.-----.-+   +---.-----+
           :  Link  :      \       ,-----.      /     /  ,-----.  \
           +........+       +-----[  Sub  ]----+      +-[  Sub  ]-+
                                  [Network]             [Network]
                                   `-----'               `-----'

           |<-DN IP->|    |<----- DetNet IP ---->|      |<-DN IP->|

             Figure 1: A Simple DetNet (DN) Enabled IP Network

   Figure 1 illustrates a DetNet enabled IP network.  The DetNet enabled
   end systems originate IP encapsulated traffic that is identified as
   DetNet flows, relay nodes understand the transport requirements of
   the DetNet flow and ensure that node, interface and sub-network
   resources are allocated to ensure DetNet service requirements.  The
   dotted line around the Service component of the Relay Nodes indicates
   that the transit routers are DetNet service aware but do not perform
   any DetNet service layer function, e.g., PREOF.  IEEE 802.1 TSN is an
   example sub-network type which can provide support for DetNet flows
   and service.  The mapping of IP DetNet flows to TSN streams and TSN
   protection mechanisms is covered in Section 7.





















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   IP  DetNet       Relay          Transit       Relay       IP DetNet
   End System       Node            Node         Node        End System

   +---------+                                               +---------+
   |  Appl.  |<--------------- End to End Service ---------->|  Appl.  |
   +---------+    .....-----+                  +-----.....   +---------+
   | Service |<---: Service |-- DetNet flow ---| Service :-->| Service |
   +---------+    +---------+   +---------+    +---------+   +---------+
   |Transport|    |Trp| |Trp|   |Transport|    |Trp| |Trp|   |Transport|
   +-------.-+    +-.-+ +-.-+   +---.---.-+    +-.-+ +-.-+   +---.-----+
           :  Link  :    /  ,-----.  \  :  Link  :    /  ,-----.  \
           +........+    +-[  Sub  ]-+  +........+    +-[  Sub  ]-+
                           [Network]                    [Network]
                            `-----'                      `-----'

           |<-DN IP->|   |<---- DetNet MPLS ---->|      |<-DN IP->|

                Figure 2: DetNet (DN) IP Over MPLS Network

   Figure 2 illustrates a more complex DetNet enabled IP network where
   an IP flow is mapped to one or more PWs and MPLS (TE) LSPs.  The end
   systems still originate IP encapsulated traffic that is identified as
   DetNet flows.  The relay nodes follow procedures defined in
   [I-D.ietf-detnet-dp-sol-mpls] to map each DetNet flow to MPLS LSPs.
   While not shown, relay nodes can provide service layer functions such
   as PREOF over the MPLS transport layer, and this is indicated by the
   solid line for the MPLS facing portion of the Service component.
   Note that the Transit node is MPLS (TE) LSP aware and performs
   switching based on MPLS labels, and need not have any specific
   knowledge of the DetNet service or the corresponding DetNet flow
   identification.  See [I-D.ietf-detnet-dp-sol-mpls] for details on the
   mapping of IP flows to MPLS as well as general support for DetNet
   services using MPLS.


















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   IP               Edge                        Edge         IP
   End System       Node                        Node         End System

   +---------+    +.........+                  +.........+   +---------+
   |  Appl.  |<---:Svc Proxy:-- E2E Service ---:Svc Proxy:-->|  Appl.  |
   +---------+    +---------+                  +---------+   +---------+
   |   IP    |    |IP | |Svc|<-- DetNet flow ->|Svc| |IP |   |   IP    |
   +---------+    +---+ +---+                  +---+ +---+   +---------+
   |Transport|    |Trp| |Trp|                  |Trp| |Trp|   |Transport|
   +-------.-+    +-.-+ +-.-+                  +-.-+ +-.-+   +---.-----+
           :  Link  :      \       ,-----.      /     /  ,-----.  \
           +........+       +-----[  Sub  ]---+      +-[  Sub  ]-+
                                  [Network]            [Network]
                                   `-----'              `-----'

         |<----IP --->|    |<----- DetNet IP ------>|     |<----IP --->|

      Figure 3: Non-DetNet aware IP end systems with IP DetNet Domain

   Figure 3 illustrates a variant of Figure 1 where the end systems are
   not DetNet aware.  In this case, edge nodes sit at the boundary of
   the DetNet domain and act as DetNet service proxies for the end
   applications by initiating and terminating DetNet service for the
   non-DetNet aware IP flows.  The existing header information or an
   approach such as described in Section 4.7 can be used to support
   DetNet flow identification.

3.1.  DetNet IP Flow Identification

   DetNet IP flows are identified based on IP, both IPv4 [RFC0791] and
   IPv6 [RFC8200], header information.  6 header fields are used and
   this set of fields is commonly referred to as the IP header
   "6-tuple".  The 6 fields include the IP source and destination
   address fields, the next level protocol or header field, the next
   level protocol (e.g.  TCP or UDP) source and destination ports, and
   the IPv4 Type of Service or IPv6 Traffic Class field (i.e., DSCP).
   As part of single DetNet flow identification, any of the fields can
   be ignored (wildcarded), and bit masks, prefix based longest match,
   and ranges can also be used.

   DetNet flow aggregation may be enabled via the use of wildcards,
   masks, prefixes and ranges.  IP tunnels may also be used to support
   flow aggregation.  In these cases, it is expected that DetNet aware
   intermediate nodes will provide DetNet service assurance on the
   aggregate through resource allocation and congestion control
   mechanisms.





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3.2.  DetNet Data Plane Requirements

   Two major groups of scenarios can be distinguished which require flow
   identification during transport:

   1.  DetNet function related scenarios:

       Congestion protection and latency control:

          Usage of allocated resources (queuing, policing, shaping) to
          ensure that the congestion-related loss and latency/jitter
          requirements of a DetNet flow are met.

          Explicit routes: a reservation that maps a flow to a specific
          path, which also limits miss-ordering and jitter.  The
          spreading of a single DetNet flow across multiple paths, e.g.,
          via ECMP, also impacts ordering and end-to-end jitter, and as
          such use of multiple paths for support of a single DetNet flow
          is is out of scope this document.

       Service protection:

          Which in the case of this document translates to changing the
          explicit path after a failure is detected while maintaining
          the required DetNet service characteristics.  Path changes,
          even in the case of failure recovery, can lead to the out of
          order delivery of data.  Note: DetNet PREOF is not provided by
          the mechanisms defined in this document.

   2.  OAM function related scenarios:

       Troubleshooting:

          For example, identify misbehaving flows.

       Recognize flow(s) for analytics:

          For example, increase counters.

       Correlate events with flows:

          For example, volume above threshold.

4.  DetNet IP Data Plane Considerations

   This section provides informative considerations related to providing
   DetNet services via IP.




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4.1.  End-system specific considerations

   Data-flows requiring DetNet service are generated and terminated on
   end systems.  The specific protocols used by an end system are
   specific to an application.  This said, DetNet's use of 6-tuple IP
   flow identification means that DetNet must be aware of not only the
   format of the IP header, but also of the next protocol carried within
   an IP packet.

   When IP end systems are DetNet aware, no application-level or
   service-level proxy functions are needed inside the DetNet domain, so
   end systems peer with end systems using the same application
   encapsulation format (see Figure 4).

             +-----+
             |  X  |                               +-----+
             +-----+                               |  X  |
             |  IP |               ________        +-----+
             +-----+     _____    /        \       |  IP |
                    \   /     \__/          \___   +-----+
                     \ /                        \ /
                      0========= flow-1 =========0_
                      |                             \
                       \                             |
                       0========== flow-2 ==========0
                      / \                        __/ \
               +-----+   \__     DetNet domain  /     \
               |  X  |      \         __       /       +-----+
               +-----+       \_______/  \_____/        |  X  |
               |  IP |                                 +-----+
               +-----+                                 |  IP |
                                                       +-----+


                Figure 4: End-systems and the DetNet domain

   End systems need to ensure that DetNet service requirements are met
   when processing packets associated with a DetNet flow.  When
   transporting packets, this generally means that packets are
   appropriately shaped on transmission and received appropriate traffic
   treatment on the connected sub-network, see Section 4.6 and
   Section 4.2.1 for more details.  When receiving packets, this
   generally means that there are appropriate local node resources,
   e.g., buffers, to receive and process a DetNet flow packets.







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4.2.  DetNet domain specific considerations

   As a general rule, DetNet domains need to be able to forward any
   DetNet flow identified by the IP 6-tuple.  Doing otherwise would
   limit end system encapsulation format.  From a practical standpoint
   this means that all nodes along the end-to-end path of a DetNet flows
   need to agree on what fields are used for flow identification, and
   the transport protocols (e.g., TCP/UDP/IPsec) which can be used to
   identify 6-tuple protocol ports.

   [Editor's note: Update accordingly.  BV to take a pass at update.]

   From a connection type perspective three scenarios are identified:

   1.  Directly attached: end system is directly connected to an edge
       node.

   2.  Indirectly attached: end system is behind a (L2-TSN / L3-DetNet)
       sub-networks.

   3.  DN integrated: end system is part of the DetNet domain.

   L3 end systems may use any of these connection types, however L2 end
   systems may use only the first two (directly or indirectly attached).
   DetNet domain MUST allow communication between any end-systems of the
   same type (L2-L2, L3-L3), independent of their connection type and
   DetNet capability.  However, directly attached and indirectly
   attached end systems have no knowledge about the DetNet domain and
   its encapsulation format at all.  See Figure 5 for L3 end system
   connection scenarios.

                                               ____+----+
                       +----+        _____    /    | ES3|
                       | ES1|____   /     \__/     +----+___
                       +----+    \ /                        \
                                  +                          |
                          ____     \                        _/
            +----+     __/    \     +__    DetNet domain   /
            | ES2|____/  L2/L3 |___/   \         __     __/
            +----+    \_______/         \_______/  \___/



               Figure 5: Connection types of L3 end systems







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4.2.1.  DetNet Routers

   Within a DetNet domain, the DetNet enabled IP Routers interconnect
   links and sub-networks to support end-to-end delivery of DetNet
   flows.  From a DetNet architecture perspective, these routers are
   DetNet relays, as they must be DetNet service aware.  Such routers
   identify DetNet flows based on the IP 6-tuple, and ensure that the
   DetNet service required traffic treatment is provided both on the
   node and on any attached sub-network.

   This solution provides DetNet functions end to end, but does so on a
   per link and sub-network basis.  Congestion protection and latency
   control and the resource allocation (queuing, policing, shaping) are
   supported using the underlying link / sub net specific mechanisms.
   However, service protections (packet replication and packet
   emilination functions) are not provided at the DetNet layer end to
   end.  But such service protection can be provided on a per underlying
   L2 link and sub-network basis.

                     +------+                         +------+
                     |  X   |                         |  X   |
                     +======+                         +------+
          End-system |  IP  |                         |  IP  |
                -----+------+-------+======+---     --+======+--
          DetNet                    |L2/SbN|          |L2/SbN|
                                    +------+          +------+


   Figure 6: Encapsulation of DetNet Routing in simplified IP service L3
                                end-systems

   Note: the DetNet Service Flow MUST be mapped to the link / sub-
   network specific resources using an underlying system specific means.
   This implies each DetNet aware node on path MUST look into the
   transported DetNet Service Flow packet and utilize e.g., a 5- (or 6-)
   tuple to find out the required mapping within a node.  As noted
   earlier, the Service Protection is done within each link / sub-
   network independently using the domain specific mechanisms (due the
   lack of a unified end to end sequencing information that would be
   available for intermediate nodes).  If end to end service protection
   is desired that can be implemented, for example, by the DetNet end
   systems using Layer-4 (L4) transport protocols or application
   protocols.  However, these are out of scope of this document.

   [Editor's note: the service protection to be clarified further.]






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4.3.  Networks with multiple technology segments

   There are network scenarios, where the DetNet domain contains
   multiple technology segments (IEEE 802.1 TSN, MPLS) and all those
   segments are under the same administrative control (see Figure 7).
   Furthermore, DetNet nodes may be interconnected via TSN segments.

   DetNet routers ensure that detnet service requirements are met per
   hop by allocating local resources, both receive and transmit, and by
   mapping the service requirements of each flow to appropriate sub-
   network mechanisms.  Such mapping is sub-network technology specific.
   The mapping of IP DetNet Flows to MPLS is covered
   [I-D.ietf-detnet-dp-sol-mpls].  The mapping of IP DetNet Flows to
   IEEE 802.1 TSN is covered in Section 7.

                                      ______
                            _____    /      \__
               ____        /     \__/          \___    ______
   +----+   __/    +======+                        +==+      \   +----+
   |src |__/  Seg1  )     |                        |  \  Seg3 \__| dst|
   +----+  \_______+      \        Segment-2       |   \+_____/  +----+
                    \======+__                    _+===/
                              \         __     __/
                               \_______/  \___/


         Figure 7: DetNet domains and multiple technology segments

4.4.  OAM

   [Editor's note: This section is TBD]

4.5.  Class of Service

   [Editor's note: this section is TBD]

   Class and quality of service, i.e., CoS and QoS, are terms that are
   often used interchangeably and confused.  In the context of DetNet,
   CoS is used to refer to mechanisms that provide traffic forwarding
   treatment based on aggregate group basis and QoS is used to refer to
   mechanisms that provide traffic forwarding treatment based on a
   specific DetNet flow basis.  Examples of existing network level CoS
   mechanisms include DiffServ which is enabled by IP header
   differentiated services code point (DSCP) field [RFC2474] and MPLS
   label traffic class field [RFC5462], and at Layer-2, by IEEE 802.1p
   priority code point (PCP).





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   CoS for DetNet flows carried in PWs and MPLS is provided using the
   existing MPLS Differentiated Services (DiffServ) architecture
   [RFC3270].  Both E-LSP and L-LSP MPLS DiffServ modes MAY be used to
   support DetNet flows.  The Traffic Class field (formerly the EXP
   field) of an MPLS label follows the definition of [RFC5462] and
   [RFC3270].  The Uniform, Pipe, and Short Pipe DiffServ tunneling and
   TTL processing models are described in [RFC3270] and [RFC3443] and
   MAY be used for MPLS LSPs supporting DetNet flows.  MPLS ECN MAY also
   be used as defined in ECN [RFC5129] and updated by [RFC5462].

   CoS for DetNet flows carried in IPv6 is provided using the standard
   differentiated services code point (DSCP) field [RFC2474] and related
   mechanisms.  The 2-bit explicit congestion notification (ECN)
   [RFC3168] field MAY also be used.

   One additional consideration for DetNet nodes which support CoS
   services is that they MUST ensure that the CoS service classes do not
   impact the congestion protection and latency control mechanisms used
   to provide DetNet QoS.  This requirement is similar to requirement
   for MPLS LSRs to that CoS LSPs do not impact the resources allocated
   to TE LSPs via [RFC3473].

4.6.  Quality of Service

   [Editor's note: Keep this section.  We should document the used
   technologies but the detailed discussion may go somewhere else.  We
   should start having it here and then decide whether to move to some
   other document.]

   Quality of Service (QoS) mechanisms for flow specific traffic
   treatment typically includes a guarantee/agreement for the service,
   and allocation of resources to support the service.  Example QoS
   mechanisms include discrete resource allocation, admission control,
   flow identification and isolation, and sometimes path control,
   traffic protection, shaping, policing and remarking.  Example
   protocols that support QoS control include Resource ReSerVation
   Protocol (RSVP) [RFC2205] (RSVP) and RSVP-TE [RFC3209] and [RFC3473].
   The existing MPLS mechanisms defined to support CoS [RFC3270] can
   also be used to reserve resources for specific traffic classes.

   In addition to explicit routes, and packet replication and
   elimination, DetNet provides zero congestion loss and bounded latency
   and jitter.  As described in [I-D.ietf-detnet-architecture], there
   are different mechanisms that maybe used separately or in combination
   to deliver a zero congestion loss service.  These mechanisms are
   provided by the either the MPLS or IP layers, and may be combined
   with the mechanisms defined by the underlying network layer such as
   802.1TSN.



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   A baseline set of QoS capabilities for DetNet flows carried in PWs
   and MPLS can provided by MPLS with Traffic Engineering (MPLS-TE)
   [RFC3209] and [RFC3473].  TE LSPs can also support explicit routes
   (path pinning).  Current service definitions for packet TE LSPs can
   be found in "Specification of the Controlled Load Quality of
   Service", [RFC2211], "Specification of Guaranteed Quality of
   Service", [RFC2212], and "Ethernet Traffic Parameters", [RFC6003].
   Additional service definitions are expected in future documents to
   support the full range of DetNet services.  In all cases, the
   existing label-based marking mechanisms defined for TE-LSPs and even
   E-LSPs are use to support the identification of flows requiring
   DetNet QoS.

   QoS for DetNet service flows carried in IP MUST be provided locally
   by the DetNet-aware hosts and routers supporting DetNet flows.  Such
   support will leverage the underlying network layer such as 802.1TSN.
   The traffic control mechanisms used to deliver QoS for IP
   encapsulated DetNet flows are expected to be defined in a future
   document.  From an encapsulation perspective, the combination of the
   "6 tuple" i.e., the typical 5 tuple enhanced with the DSCP code,
   uniquely identifies a DetNet service flow.

   Packets that are marked with a DetNet Class of Service value, but
   that have not been the subject of a completed reservation, can
   disrupt the QoS offered to properly reserved DetNet flows by using
   resources allocated to the reserved flows.  Therefore, the network
   nodes of a DetNet network must:

   o  Defend the DetNet QoS by discarding or remarking (to a non-DetNet
      CoS) packets received that are not the subject of a completed
      reservation.

   o  Not use a DetNet reserved resource, e.g. a queue or shaper
      reserved for DetNet flows, for any packet that does not carry a
      DetNet Class of Service marker.

4.7.  Cross-DetNet flow resource aggregation

   [Editor's note: Aggregation is FFS.  The addregation can be provided
   via encapsulation or header wildcards]

   The ability to aggregate individual flows, and their associated
   resource control, into a larger aggregate is an important technique
   for improving scaling of control in the data, management and control
   planes.  This document identifies the traffic identification related
   aspects of aggregation of DetNet flows.  The resource control and
   management aspects of aggregation (including the queuing/shaping/
   policing implications) will be covered in other documents.  The data



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   plane implications of aggregation are independent for PW/MPLS and IP
   encapsulated DetNet flows.

   DetNet flows transported via IP have more limited aggregation
   options, due to the available traffic flow identification fields of
   the IP solution.  One available approach is to manage the resources
   associated with a DSCP identified traffic class and to map (remark)
   individually controlled DetNet flows onto that traffic class.  This
   approach also requires that nodes support aggregation ensure that
   traffic from aggregated LSPs are placed (shaped/policed/enqueued) in
   a fashion that ensures the required DetNet service is preserved.

   In both the MPLS and IP cases, additional details of the traffic
   control capabilities needed at a DetNet-aware node may be covered in
   the new service descriptions mentioned above or in separate future
   documents.  Management and control plane mechanisms will also need to
   ensure that the service required on the aggregate flow (H-LSP or
   DSCP) are provided, which may include the discarding or remarking
   mentioned in the previous sections.

4.8.  Time synchronization

   While time synchronization can be important both from the perspective
   of operating the DetNet network itself and from the perspective of
   DetNet-based applications, time synchronization is outside the scope
   of this document.  This said, a DetNet node can also support time
   synchronization or distribution mechanisms.

   For example, [RFC8169] describes a method of recording the packet
   queuing time in an MPLS LSR on a packet by per packet basis and
   forwarding this information to the egress edge system.  This allows
   compensation for any variable packet queuing delay to be applied at
   the packet receiver.  Other mechanisms for IP networks are defined
   based on IEEE Standard 1588 [IEEE1588], such as ITU-T [G.8275.1] and
   [G.8275.2].

   A more detailed discussion of time synchronization is outside the
   scope of this document.

5.  Management and control plane considerations

   [Editor's note: This section needs to be different for MPLS and IP
   solutions.  Most solutions are technology dependant.]

   While management plane and control plane are traditionally considered
   separately, from the Data Plane perspective there is no practical
   difference based on the origin of flow provisioning information.
   This document therefore does not distinguish between information



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   provided by a control plane protocol, e.g., RSVP-TE [RFC3209] and
   [RFC3473], or by a network management mechanisms, e.g., RestConf
   [RFC8040] and YANG [RFC7950].

   [Editor's note: This section is a work in progress.  discuss here
   what kind of enhancements are needed for DetNet and specifically for
   PREOF and DetNet zero congest loss and latency control.  Need to
   cover both traffic control (queuing) and connection control (control
   plane).]

5.1.  Explicit routes

   [Editor's note: this is TBD.]

5.2.  Service protection

   [Editor's note: this is TBD.]

5.3.  Congestion protection and latency control

   [Editor's note: this is TBD.]

5.4.  Flow aggregation control

   [Editor's note: this is TBD.]

5.5.  Bidirectional traffic

   [Editor's note: This is managed at the management plane or controller
   level.]

   Some DetNet applications generate bidirectional traffic.  While the
   DetNet data plane must support bidirectional DetNet flows, there are
   no special bidirectional features with respect to the data plane
   other than need for the two directions take the same paths.  That is
   to say that bidirectional DetNet flows are solely represented at the
   management and control plane levels, without specific support or
   knowledge within the DetNet data plane.  Fate sharing and associated
   vs co-routed bidirectional flows can be managed at the control level.
   Note, that there is no stated requirement for bidirectional DetNet
   flows to be supported using the same 6-tuple in each direction.
   Control mechanisms will need to support such bidirectional flows but
   such mechanisms are out of scope of this document.  An example
   control plane solution for MPLS can be found in [RFC7551].







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6.  DetNet IP Encapsulation Procedures

   [Editor's note: RFC2119 conformance language goes here Need to
   support flow identification Based on 4 IP header fields {ip addrs,
   dscp, nct protocol} need to support port identification for TCP/UDP,
   IPsec spi (?), what else?  Service proxies -- basically same from
   data plane, different from management map to local resources]

6.1.  Multi-Path Considerations

   [Note: talk about implications of ECMP/LAG/parallel links -- perhaps
   just say support for such is not covered in the document.]

7.  Mapping IP DetNet Flows to IEEE 802.1 TSN

   [Editor's note: This section is TBD - it covers how IP DetNet flows
   operate over an IEEE 802.1 TSN sub-network.  BV to take a pass at
   filling in this section]

   The Time-Sensitive Networking (TSN) Task Group of the IEEE 802.1
   Working Group have defined (and are defining) a number of amendments
   to IEEE 802.1Q [IEEE8021Q] that provide zero congestion loss and
   bounded latency in bridged networks.  IEEE 802.1CB [IEEE8021CB]
   defines packet replication and elimination functions that should
   prove both compatible with and useful to, DetNet networks.

   As is the case for DetNet, a Layer 2 network node such as a bridge
   may need to identify the specific DetNet flow to which a packet
   belongs in order to provide the TSN/DetNet QoS for that packet.  It
   also will likely need a CoS marking, such as the priority field of an
   IEEE Std 802.1Q VLAN tag, to give the packet proper service.

   Although the flow identification methods described in IEEE 802.1CB
   [IEEE8021CB] are flexible, and in fact, include IP 5-tuple
   identification methods, the baseline TSN standards assume that every
   Ethernet frame belonging to a TSN stream (i.e.  DetNet flow) carries
   a multicast destination MAC address that is unique to that flow
   within the bridged network over which it is carried.  Furthermore,
   IEEE 802.1CB [IEEE8021CB] describes three methods by which a packet
   sequence number can be encoded in an Ethernet frame.

   Ensuring that the proper Ethernet VLAN tag priority and destination
   MAC address are used on a DetNet/TSN packet may require further
   clarification of the customary L2/L3 transformations carried out by
   routers and edge label switches.  Edge nodes may also have to move
   sequence number fields among Layer 2, PW, and IPv6 encapsulations.





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7.1.  TSN Stream ID Mapping

   [Editor's Note: This section covers the data plane aspects of mapping
   an IP DetNet flow to one or more TSN Stream-IDs.]

7.2.  TSN Usage of FRER

   [Core point] TSN Streams support DetNet flows may use Frame
   Replication and Elimination for Redundancy (FRER) [802.1CB] based on
   the loss service requirements of the TSN Stream, which is derived
   from the DetNet service requirements of the DetNet mapped flow.  The
   specific operation of the FRER is not modified by the use of DetNe
   and follows IEEE 802.1CB [IEEE8021CB].

7.3.  Management and Control Implications

   [Editor's note: This section is TBD Covers Creation, mapping, removal
   of TSN Stream IDs, related parameters and,when needed, configuration
   of FRER.  Supported by management/control plane.]

8.  Security considerations

   The security considerations of DetNet in general are discussed in
   [I-D.ietf-detnet-architecture] and [I-D.ietf-detnet-security].  Other
   security considerations will be added in a future version of this
   draft.

9.  IANA considerations

   TBD.

10.  Contributors

   RFC7322 limits the number of authors listed on the front page of a
   draft to a maximum of 5, far fewer than the 20 individuals below who
   made important contributions to this draft.  The editor wishes to
   thank and acknowledge each of the following authors for contributing
   text to this draft.  See also Section 11.













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      Loa Andersson
      Huawei
      Email: loa@pi.nu

      Yuanlong Jiang
      Huawei
      Email: jiangyuanlong@huawei.com

      Norman Finn
      Huawei
      3101 Rio Way
      Spring Valley, CA  91977
      USA
      Email: norman.finn@mail01.huawei.com

      Janos Farkas
      Ericsson
      Magyar Tudosok krt. 11
      Budapest  1117
      Hungary
      Email: janos.farkas@ericsson.com

      Carlos J. Bernardos
      Universidad Carlos III de Madrid
      Av. Universidad, 30
      Leganes, Madrid  28911
      Spain
      Email: cjbc@it.uc3m.es

      Tal Mizrahi
      Marvell
      6 Hamada st.
      Yokneam
      Israel
      Email: talmi@marvell.com

      Lou Berger
      LabN Consulting, L.L.C.
      Email: lberger@labn.net

11.  Acknowledgements

   The author(s) ACK and NACK.

   The following people were part of the DetNet Data Plane Solution
   Design Team:

      Jouni Korhonen



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      Janos Farkas

      Norman Finn

      Balazs Varga

      Loa Andersson

      Tal Mizrahi

      David Mozes

      Yuanlong Jiang

      Carlos J.  Bernardos

   The DetNet chairs serving during the DetNet Data Plane Solution
   Design Team:

      Lou Berger

      Pat Thaler

   Thanks for Stewart Bryant for his extensive review of the previous
   versions of the document.

12.  References

12.1.  Normative references

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              DOI 10.17487/RFC0791, September 1981,
              <https://www.rfc-editor.org/info/rfc791>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC2211]  Wroclawski, J., "Specification of the Controlled-Load
              Network Element Service", RFC 2211, DOI 10.17487/RFC2211,
              September 1997, <https://www.rfc-editor.org/info/rfc2211>.

   [RFC2212]  Shenker, S., Partridge, C., and R. Guerin, "Specification
              of Guaranteed Quality of Service", RFC 2212,
              DOI 10.17487/RFC2212, September 1997,
              <https://www.rfc-editor.org/info/rfc2212>.




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   [RFC2474]  Nichols, K., Blake, S., Baker, F., and D. Black,
              "Definition of the Differentiated Services Field (DS
              Field) in the IPv4 and IPv6 Headers", RFC 2474,
              DOI 10.17487/RFC2474, December 1998,
              <https://www.rfc-editor.org/info/rfc2474>.

   [RFC3168]  Ramakrishnan, K., Floyd, S., and D. Black, "The Addition
              of Explicit Congestion Notification (ECN) to IP",
              RFC 3168, DOI 10.17487/RFC3168, September 2001,
              <https://www.rfc-editor.org/info/rfc3168>.

   [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001,
              <https://www.rfc-editor.org/info/rfc3209>.

   [RFC3270]  Le Faucheur, F., Wu, L., Davie, B., Davari, S., Vaananen,
              P., Krishnan, R., Cheval, P., and J. Heinanen, "Multi-
              Protocol Label Switching (MPLS) Support of Differentiated
              Services", RFC 3270, DOI 10.17487/RFC3270, May 2002,
              <https://www.rfc-editor.org/info/rfc3270>.

   [RFC3443]  Agarwal, P. and B. Akyol, "Time To Live (TTL) Processing
              in Multi-Protocol Label Switching (MPLS) Networks",
              RFC 3443, DOI 10.17487/RFC3443, January 2003,
              <https://www.rfc-editor.org/info/rfc3443>.

   [RFC3473]  Berger, L., Ed., "Generalized Multi-Protocol Label
              Switching (GMPLS) Signaling Resource ReserVation Protocol-
              Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
              DOI 10.17487/RFC3473, January 2003,
              <https://www.rfc-editor.org/info/rfc3473>.

   [RFC5129]  Davie, B., Briscoe, B., and J. Tay, "Explicit Congestion
              Marking in MPLS", RFC 5129, DOI 10.17487/RFC5129, January
              2008, <https://www.rfc-editor.org/info/rfc5129>.

   [RFC5462]  Andersson, L. and R. Asati, "Multiprotocol Label Switching
              (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic
              Class" Field", RFC 5462, DOI 10.17487/RFC5462, February
              2009, <https://www.rfc-editor.org/info/rfc5462>.

   [RFC6003]  Papadimitriou, D., "Ethernet Traffic Parameters",
              RFC 6003, DOI 10.17487/RFC6003, October 2010,
              <https://www.rfc-editor.org/info/rfc6003>.






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   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

12.2.  Informative references

   [G.8275.1]
              International Telecommunication Union, "Precision time
              protocol telecom profile for phase/time synchronization
              with full timing support from the network", ITU-T
              G.8275.1/Y.1369.1 G.8275.1, June 2016,
              <https://www.itu.int/rec/T-REC-G.8275.1/en>.

   [G.8275.2]
              International Telecommunication Union, "Precision time
              protocol telecom profile for phase/time synchronization
              with partial timing support from the network", ITU-T
              G.8275.2/Y.1369.2 G.8275.2, June 2016,
              <https://www.itu.int/rec/T-REC-G.8275.2/en>.

   [I-D.ietf-detnet-architecture]
              Finn, N., Thubert, P., Varga, B., and J. Farkas,
              "Deterministic Networking Architecture", draft-ietf-
              detnet-architecture-05 (work in progress), May 2018.

   [I-D.ietf-detnet-dp-sol-mpls]
              Korhonen, J., Varga, B., "DetNet MPLS Data Plane
              Encapsulation", 2018.

   [I-D.ietf-detnet-security]
              Mizrahi, T., Grossman, E., Hacker, A., Das, S., Dowdell,
              J., Austad, H., Stanton, K., and N. Finn, "Deterministic
              Networking (DetNet) Security Considerations", draft-ietf-
              detnet-security-02 (work in progress), April 2018.

   [IEEE1588]
              IEEE, "IEEE 1588 Standard for a Precision Clock
              Synchronization Protocol for Networked Measurement and
              Control Systems Version 2", 2008.







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   [IEEE8021CB]
              Finn, N., "Draft Standard for Local and metropolitan area
              networks - Seamless Redundancy", IEEE P802.1CB
              /D2.1 P802.1CB, December 2015,
              <http://www.ieee802.org/1/files/private/cb-drafts/
              d2/802-1CB-d2-1.pdf>.

   [IEEE8021Q]
              IEEE 802.1, "Standard for Local and metropolitan area
              networks--Bridges and Bridged Networks (IEEE Std 802.1Q-
              2014)", 2014, <http://standards.ieee.org/about/get/>.

   [RFC2205]  Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S.
              Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
              Functional Specification", RFC 2205, DOI 10.17487/RFC2205,
              September 1997, <https://www.rfc-editor.org/info/rfc2205>.

   [RFC3670]  Moore, B., Durham, D., Strassner, J., Westerinen, A., and
              W. Weiss, "Information Model for Describing Network Device
              QoS Datapath Mechanisms", RFC 3670, DOI 10.17487/RFC3670,
              January 2004, <https://www.rfc-editor.org/info/rfc3670>.

   [RFC7551]  Zhang, F., Ed., Jing, R., and R. Gandhi, Ed., "RSVP-TE
              Extensions for Associated Bidirectional Label Switched
              Paths (LSPs)", RFC 7551, DOI 10.17487/RFC7551, May 2015,
              <https://www.rfc-editor.org/info/rfc7551>.

   [RFC7657]  Black, D., Ed. and P. Jones, "Differentiated Services
              (Diffserv) and Real-Time Communication", RFC 7657,
              DOI 10.17487/RFC7657, November 2015,
              <https://www.rfc-editor.org/info/rfc7657>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8169]  Mirsky, G., Ruffini, S., Gray, E., Drake, J., Bryant, S.,
              and A. Vainshtein, "Residence Time Measurement in MPLS
              Networks", RFC 8169, DOI 10.17487/RFC8169, May 2017,
              <https://www.rfc-editor.org/info/rfc8169>.







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Appendix A.  Example of DetNet data plane operation

   [Editor's note: Add a simplified example of DetNet data plane and how
   labels etc work in the case of MPLS-based PSN and utilizing PREOF.
   The figure is subject to change depending on the further DT decisions
   on the label handling..]

Appendix B.  Example of pinned paths using IPv6

   TBD.

Authors' Addresses

   Jouni Korhonen (editor)

   Email: jouni.nospam@gmail.com


   Balazs Varga (editor)
   Ericsson
   Magyar Tudosok krt. 11.
   Budapest  1117
   Hungary

   Email: balazs.a.varga@ericsson.com


























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