DetNet

Internet Engineering Task Force (IETF)                     B. Varga, Ed.
Internet-Draft
Request for Comments: 9037                                     J. Farkas
Intended status:
Category: Informational                                         Ericsson
Expires: August 23, 2021
ISSN: 2070-1721                                                 A. Malis
                                                        Malis Consulting
                                                               S. Bryant
                                                  Futurewei Technologies
                                                       February 19,
                                                               June 2021

DetNet

Deterministic Networking (DetNet) Data Plane: MPLS over IEEE 802.1 Time-Sensitive Time-
                       Sensitive Networking (TSN)
                   draft-ietf-detnet-mpls-over-tsn-07

Abstract

   This document specifies the Deterministic Networking (DetNet) MPLS
   data plane when operating over an IEEE 802.1 Time-Sensitive
   Networking (TSN) sub-network.  This document does not define new
   procedures or processes.  Whenever this document makes statements or
   recommendations, these they are taken from normative text in the referenced
   RFCs.

Status of This Memo

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

   Internet-Drafts are working documents not an Internet Standards Track specification; it is
   published for informational purposes.

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   (IETF).  Note that other groups may also distribute
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   This Internet-Draft will expire on August 23, 2021.
   https://www.rfc-editor.org/info/rfc9037.

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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
   3.  DetNet MPLS Data Plane Overview . . . . . . . . . . . . . . .   3
   4.  DetNet MPLS Operation Over over IEEE 802.1 TSN Sub-Networks  . . .   4 Sub-networks
     4.1.  Functions for DetNet Flow to TSN Stream Mapping . . . . .   6
     4.2.  TSN requirements Requirements of MPLS DetNet nodes . . . . . . . . . .   6 Nodes
     4.3.  Service protection Protection within the TSN sub-network . . . . . .   8 Sub-network
     4.4.  Aggregation during DetNet flow Flow to TSN Stream mapping  . .   8 Mapping
   5.  Management and Control Implications . . . . . . . . . . . . .   8
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  11
     9.1.
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .  11
     9.2.
     8.2.  Informative References  . . . . . . . . . . . . . . . . .  11
   Acknowledgements
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   Deterministic Networking (DetNet) is a service that can be offered by
   a network to DetNet flows.  DetNet provides these flows with low
   packet loss rate and assured maximum end-to-end delivery latency.
   General background and concepts of DetNet can be found in [RFC8655].

   The DetNet Architecture architecture decomposes the DetNet related DetNet-related data plane
   functions into two sub-layers: a service sub-layer and a forwarding
   sub-layer.  The service sub-layer is used to provide DetNet service
   protection and reordering.  The forwarding sub-layer is used to
   provide congestion protection (low loss, assured latency, and limited
   reordering) leveraging MPLS Traffic Engineering mechanisms.

   [RFC8964] specifies the DetNet data plane operation for an MPLS-based
   Packet Switched Network (PSN).  MPLS encapsulated
   PSN.  MPLS-encapsulated DetNet flows can be carried over network
   technologies that can provide the DetNet
   required DetNet-required level of service.
   This document focuses on the scenario where MPLS (DetNet) nodes are
   interconnected by a an IEEE 802.1 TSN sub-
   network. sub-network.  There is close
   cooperation between the IETF DetNet WG Working Group and the IEEE 802.1 TSN TG.
   Time-Sensitive Networking Task Group (TSN TG).

2.  Terminology

2.1.  Terms Used in This Document

   This document uses the terminology established in the DetNet
   architecture [RFC8655] and [RFC8964].  TSN specific  TSN-specific terms are defined in
   the TSN TG of the IEEE 802.1 Working Group.  The reader is assumed to
   be familiar with these documents and their terminology.

2.2.  Abbreviations

   The following abbreviations are used in this document:

   A-Label       Aggregation label, label; a special case of an S-Label.

   d-CW          DetNet Control Word. Word

   DetNet        Deterministic Networking. Networking

   F-Label       Forwarding label that identifies the LSP used by a
                 DetNet flow.

   FRER          Frame Replication and Elimination for Redundancy (TSN
                 function).
                 function)

   L2            Layer 2. 2

   L3            Layer 3. 3

   LSP           Label Switched Path

   MPLS          Multiprotocol Label Switching. Switching

   PREOF         Packet Replication, Elimination Elimination, and Ordering Functions. Functions

   PSN           Packet Switched Network. Network

   PW            PseudoWire.            Pseudowire

   RSVP-TE       Resource Reservation Protocol - Traffic Engineering. Engineering

   S-Label       Service label. label

   TSN           Time-Sensitive Network. Networking

3.  DetNet MPLS Data Plane Overview

   The basic approach defined in [RFC8964] supports the DetNet service
   sub-layer based on existing pseudowire (PW) PW encapsulations and
   mechanisms, mechanisms and
   supports the DetNet forwarding sub-layer based on existing MPLS
   Traffic Engineering encapsulations and mechanisms.

   A node operating operates on a DetNet flow in the Detnet DetNet service sub-layer,
   i.e.
   i.e., a node processing a DetNet packet which that has the S-Label service label
   (S-Label) as the top of stack uses the local context associated with
   that service label
   (S-Label), S-Label, for example example, a received forwarding label (F-Label), to
   determine what local DetNet operation(s) are is applied to that packet.
   An S-Label may be unique when taken from the platform label space
   [RFC3031], which would enable correct DetNet flow identification
   regardless of which input interface or LSP the packet arrives on.
   The service sub-layer functions (i.e., PREOF) use a DetNet control
   word (d-CW). d-CW.

   The DetNet MPLS data plane builds on MPLS Traffic Engineering
   encapsulations and mechanisms to provide a forwarding sub-layer that
   is responsible for providing resource allocation and explicit routes.
   The forwarding sub-layer is supported by one or more F-Labels.

   DetNet edge/relay nodes are DetNet service sub-layer aware, sub-layer-aware,
   understand the particular needs of DetNet flows flows, and provide both
   DetNet service and forwarding sub-layer functions.  They add, remove remove,
   and process d-CWs, S-Labels S-Labels, and F-labels F-Labels as needed.  MPLS DetNet
   nodes and transit nodes include DetNet forwarding sub-layer
   functions, notably notable support for explicit routes, and resources resource
   allocation to eliminate (or reduce) congestion loss and jitter.
   Unlike other DetNet node types, transit nodes provide no service sub-
   layer processing.

   MPLS (DetNet) nodes and transit nodes interconnected by a TSN sub-
   network are the primary focus of this document.  The mapping of
   DetNet MPLS flows to TSN streams Streams and TSN protection mechanisms are
   covered in Section 4.

4.  DetNet MPLS Operation Over over IEEE 802.1 TSN Sub-Networks Sub-networks

   The DetNet WG collaborates with IEEE 802.1 TSN in order to define a
   common architecture for both Layer 2 and Layer 3, 3 that maintains
   consistency across diverse networks.  Both DetNet MPLS and TSN use
   the same techniques to provide their deterministic service:

   o

   *  Service protection.

   o protection

   *  Resource allocation.

   o allocation

   *  Explicit routes. routes

   As described in the DetNet architecture [RFC8655] [RFC8655], from the MPLS
   perspective, a sub-network provides from MPLS perspective a single hop single-hop connection between
   MPLS (DetNet) nodes.  Functions used for resource allocation and
   explicit routes are treated as domain internal functions and do not
   require function interworking across the DetNet MPLS network and the
   TSN sub-
   network. sub-network.

   In the case of the service protection function function, due to the
   similarities of the DetNet PREOF and TSN FRER functions functions, some level
   of interworking is possible.  However, such interworking is out-of-scope
   in out of
   scope of this document and left for further study.

   Figure 1 illustrates a scenario, scenario where two MPLS (DetNet) nodes are
   interconnected by a TSN sub-network.  Node-1 is single homed single-homed, and
   Node-2 is dual-homed to the TSN sub-network.

      MPLS (DetNet)                 MPLS (DetNet)
         Node-1                        Node-2

      +----------+                  +----------+
   <--| Service* |-- DetNet flow ---| Service* |-->
      +----------+                  +----------+
      |Forwarding|                  |Forwarding|
      +--------.-+    <-TSN Str->   +-.-----.--+
                \      ,-------.     /     /
                 +----[ TSN-Sub ]---+ TSN Sub-]---+     /
                      [ Network network ]--------+
                       `-------'
   <---------------- DetNet MPLS --------------->

   Note: * no service sub-layer required for transit nodes

        Figure 1: DetNet Enabled DetNet-Enabled MPLS Network Over over a TSN Sub-Network Sub-network

   At the time of this writing, the Time-Sensitive Networking (TSN) Task
   Group TSN TG of the IEEE 802.1 Working
   Group have defined (and are defining) a number of amendments to
   [IEEE8021Q] that provide zero congestion loss and bounded latency in
   bridged networks.  Furthermore  Furthermore, [IEEE8021CB] defines frame
   replication and elimination functions for reliability that should
   prove both compatible with and useful to, to DetNet networks.  All these
   functions have to identify flows those that require TSN treatment (i.e.,
   applying TSN functions during forwarding).

   TSN capabilities of the TSN sub-network are made available for MPLS
   (DetNet) flows via the protocol interworking function defined in
   Annex C.5 of [IEEE8021CB].  For example, when applied on the TSN edge port
   port, it can convert an ingress unicast MPLS (DetNet) flow to use a
   specific Layer-2 Layer 2 multicast destination MAC Media Access Control (MAC)
   address and a VLAN, in order to direct the packet through a specific
   path inside the bridged network.  A similar interworking function
   pair at the other end of the TSN sub-network would restore the packet
   to its original Layer-2 Layer 2 destination MAC address and VLAN.

   Placement

   The placement of TSN functions depends on the TSN capabilities of the
   nodes along the path.  MPLS (DetNet) Nodes nodes may or may not support TSN
   functions.  For a given TSN Stream (i.e., DetNet flow) flow), an MPLS
   (DetNet) node is treated as a Talker or a Listener inside the TSN
   sub-network.

4.1.  Functions for DetNet Flow to TSN Stream Mapping

   Mapping of a DetNet MPLS flow to a TSN Stream is provided via the
   combination of a passive and an active stream Stream identification function
   that operate at the frame level.  The passive stream Stream identification
   function is used to catch the MPLS label(s) of a DetNet MPLS flow flow,
   and the active stream Stream identification function is used to modify the
   Ethernet header according to the ID of the mapped TSN Stream.

   Clause 6.8 of [IEEEP8021CBdb] defines a Mask-and-Match Stream
   identification function that can be used as a passive function for
   MPLS DetNet flows.

   Clause 6.6 of [IEEE8021CB] defines an Active Destination MAC and a
   VLAN Stream identification function, what function that can replace some Ethernet
   header
   fields fields, namely (1) the destination MAC-address, MAC address, (2) the VLAN-ID VLAN-
   ID, and (3) priority parameters with alternate values.  Replacement
   is provided for the frame that is passed either down the stack from
   the upper layers or up the stack from the lower layers.

   Active Destination MAC and VLAN Stream identification can be used
   within a Talker to set flow identity or a Listener to recover the
   original addressing information.  It can also be used also in a TSN bridge
   that is providing translation as a proxy service for an End System. end system.

4.2.  TSN requirements Requirements of MPLS DetNet nodes Nodes

   This section covers required behavior of a TSN-aware MPLS (DetNet)
   node using a TSN sub-network.  The implementation of TSN packet packet-
   processing functions must be compliant with the relevant IEEE 802.1
   standards.

   From the TSN sub-network perspective perspective, MPLS (DetNet) nodes are treated
   as a Talker or Listener, that which may be (1) TSN-unaware or (2) TSN-aware. TSN-
   aware.

   In cases of TSN-unaware MPLS DetNet nodes nodes, the TSN relay nodes within
   the TSN sub-network must modify the Ethernet encapsulation of the
   DetNet MPLS flow (e.g., MAC translation, VLAN-ID setting, Sequence sequence
   number addition, etc.) to allow proper TSN specific TSN-specific handling inside
   the sub-network.  There are no requirements defined for TSN-unaware
   MPLS DetNet nodes in this document.

   MPLS (DetNet) nodes being that are TSN-aware can be treated as a
   combination of a TSN-unaware Talker/Listener and a TSN-Relay, as
   shown in Figure 2.  In such cases cases, the MPLS (DetNet) node must
   provide the TSN
   sub-network specific sub-network-specific Ethernet encapsulation over the
   link(s) towards the sub-network.

                 MPLS (DetNet)
                     Node
      <---------------------------------->

      +----------+
   <--| Service* |-- DetNet flow ------------------
      +----------+
      |Forwarding|
      +----------+    +---------------+
      |    L2    |    | L2 Relay with |<--- TSN ---
      |          |    | TSN function  |    Stream
      +-----.----+    +--.------.---.-+
             \__________/        \   \______
                                  \_________
       TSN-unaware
        Talker /          TSN-Bridge
        Listener             Relay
                                          <----- TSN Sub-network -----
      <------- TSN-aware Tlk/Lstn ------->

   Note: * no service sub-layer required for transit nodes

              Figure 2: MPLS (DetNet) Node with TSN Functions

   A TSN-aware MPLS (DetNet) node implementation must support the Stream
   Identification
   identification TSN component for recognizing flows.

   A Stream identification component must be able to instantiate the
   following functions functions: (1) Active Destination MAC and VLAN Stream
   identification function, (2) Mask-and-Match Stream identification
   function
   function, and (3) the related managed objects in Clause 9 of
   [IEEE8021CB] and [IEEEP8021CBdb].

   A TSN-aware MPLS (DetNet) node implementation must support the
   Sequencing function and the Sequence encode/decode function as
   defined in Clause Clauses 7.4 and 7.6 of [IEEE8021CB] in order for FRER to
   be used inside the TSN sub-network.

   The Sequence encode/decode function must support the Redundancy tag
   (R-TAG) format as per Clause 7.8 of [IEEE8021CB].

   A TSN-aware MPLS (DetNet) node implementation must support the Stream
   splitting function and the Individual recovery function as defined in
   Clause 7.7 and
   Clauses 7.5 and 7.7 of [IEEE8021CB] in order for that node to be a
   replication or elimination point for FRER.

4.3.  Service protection Protection within the TSN sub-network Sub-network

   TSN Streams supporting DetNet flows may use Frame Replication and
   Elimination for Redundancy (FRER) FRER as defined in Clause 8.
   8 of [IEEE8021CB] 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 FRER is not modified
   by the use of DetNet and follows [IEEE8021CB].

   FRER function and the provided service recovery is available only
   within the TSN sub-network as the TSN Stream-ID and the TSN sequence
   number are not valid outside the sub-network.  An MPLS (DetNet) node
   represents a an L3 border border, and as such such, it terminates all related
   information elements encoded in the L2 frames.

   As the Stream-ID and the TSN sequence number are paired with the similar
   MPLS flow parameters, FRER can be combined with PREOF functions.
   Such service protection interworking scenarios may require to move moving
   sequence number fields among TSN (L2) and PW (MPLS)
   encapsulations encapsulations,
   and they are left for further study.

4.4.  Aggregation during DetNet flow Flow to TSN Stream mapping Mapping

   Implementation of this document shall use management and control
   information to map a DetNet flow to a TSN Stream.  N:1 mapping
   (aggregating DetNet flows in a single TSN Stream) shall be supported.
   The management or control function that provisions flow mapping shall
   ensure that adequate resources are allocated and configured to
   provide proper service requirements of the mapped flows.

5.  Management and Control Implications

   Information related to DetNet flow and TSN Stream mapping related information are is required
   only for TSN-aware MPLS (DetNet) nodes.  From the Data Plane
   perspective data plane
   perspective, there is no practical difference based on the origin of
   flow mapping related
   flow-mapping-related information (management plane or control plane).

   The following summarizes the set of information that is needed to
   configure DetNet MPLS over TSN:

   o

   *  DetNet MPLS related MPLS-related configuration information according to the
      DetNet role of the DetNet MPLS node, as per [RFC8964].

   o  TSN related

   *  TSN-related configuration information according to the TSN role of
      the DetNet MPLS node, as per [IEEE8021Q], [IEEE8021CB] [IEEE8021CB], and
      [IEEEP8021CBdb].

   o

   *  Mapping between a DetNet MPLS flow(s) (label information: A-labels,
      S-labels
      A-Labels, S-Labels, and F-labels F-Labels as defined in [RFC8964]) and a
      TSN Stream(s) (as stream Stream identification information defined in
      [IEEEP8021CBdb]).
      Note,  Note that managed objects for TSN Stream
      identification can be found in [IEEEP8021CBcv].

   This information must be provisioned per DetNet flow.

   Mappings between DetNet and TSN management and control planes are out
   of scope of the this document.  Some of the challenges are highlighted
   below.

   TSN-aware MPLS DetNet nodes are members of both the DetNet domain and
   the TSN sub-network.  Within the TSN sub-network sub-network, the TSN-aware MPLS
   (DetNet) node has a TSN-aware Talker/Listener role, so TSN specific TSN-specific
   management and control plane functionalities must be implemented.
   There are many similarities in the management plane techniques used
   in DetNet and TSN, but that is not the case for the control plane
   protocols.  For example, RSVP-TE and MSRP (Multiple the Multiple Stream Registration Protocol) behaves
   Protocol (MSRP) behave differently.  Therefore  Therefore, management and
   control plane design is an are important aspect aspects of scenarios, scenarios where mapping
   between DetNet and TSN is required.

   In order to use a TSN sub-network between DetNet nodes, DetNet DetNet-
   specific information must be converted to TSN sub-network information specific
   ones. to the
   TSN sub-network.  DetNet flow ID and flow related parameters/requirements flow-related parameters/
   requirements must be converted to a TSN Stream ID and stream related parameters/
   requirements. stream-related
   parameters/requirements.  Note that, as the TSN sub-network is just a
   portion of the end-2-end end-to-end DetNet path (i.e., a single hop from the
   MPLS perspective), some parameters (e.g., delay) may differ
   significantly.  Other parameters (like bandwidth) also may have to be
   tuned due to the L2 encapsulation used within the TSN sub-network.

   In some cases cases, it may be challenging to determine some TSN Stream TSN-Stream-
   related information.  For example, on a TSN-aware MPLS (DetNet) node
   that acts as a Talker, it is quite obvious which DetNet node is the
   Listener of the mapped TSN stream Stream (i.e., the MPLS Next-Hop).  However next hop).
   However, it may be not trivial to locate the point/interface where
   that Listener is connected to the TSN sub-network.  Such attributes
   may require interaction between control and management plane
   functions and between DetNet and TSN domains.

   Mapping between DetNet flow identifiers and TSN Stream identifiers,
   if not provided explicitly, can be done by a TSN-aware MPLS (DetNet)
   node locally based on information provided for configuration of the
   TSN Stream identification functions (Mask-and-match (Mask-and-Match Stream
   identification and Active active Stream identification function). identification).

   Triggering the setup/modification of a TSN Stream in the TSN sub-
   network is an example where management and/or control plane
   interactions are required between the DetNet and TSN sub-network.
   TSN-unaware MPLS (DetNet) nodes make such a triggering even more
   complicated as they are fully unaware of the sub-network and run
   independently.

   Configuration of TSN specific TSN-specific functions (e.g., FRER) inside the TSN
   sub-network is a TSN domain specific TSN-domain-specific decision and may not be visible
   in the DetNet domain.  Service protection interworking scenarios are
   left for further study.

6.  Security Considerations

   Security considerations for DetNet are described in detail in
   [I-D.ietf-detnet-security].
   [DETNET-SECURITY].  General security considerations are described in
   [RFC8655].  Considerations specific to the DetNet MPLS data plane specific
   considerations are
   summarized in [RFC8964].  This section considers exclusively security
   considerations which that are specific to the DetNet MPLS over TSN sub-network sub-
   network scenario.

   The sub-network between DetNet nodes needs to be subject to
   appropriate confidentiality.  Additionally, knowledge of what DetNet/
   TSN services are provided by a sub-network may supply information
   that can be used in a variety of security attacks.  The ability to
   modify information exchanges between connected DetNet nodes may
   result in bogus operations.  Therefore, it is important that the
   interface between DetNet nodes and the TSN sub-network are subject to
   authorization, authentication, and encryption.

   The TSN sub-network operates at Layer-2 Layer 2, so various security
   mechanisms defined by IEEE can be used to secure the connection
   between the DetNet nodes (e.g., encryption may be provided using
   MACSec
   MACsec [IEEE802.1AE-2018]).

7.  IANA Considerations

   This document makes has no IANA requests. actions.

8.  Acknowledgements

   The authors wish to thank Norman Finn, Lou Berger, Craig Gunther,
   Christophe Mangin and Jouni Korhonen for their various contributions
   to this work.

9.  References

9.1.

8.1.  Normative References

   [IEEE8021CB]
              IEEE, "IEEE Standard for Local and metropolitan area
              networks--Frame Replication and Elimination for
              Reliability", IEEE 802.1, "Standard Std 802.1CB-2017,
              DOI 10.1109/IEEESTD.2017.8091139, October 2017,
              <https://ieeexplore.ieee.org/document/8091139>.

   [IEEEP8021CBdb]
              IEEE, "Draft Standard for Local and metropolitan area
              networks - -— Frame Replication and Elimination for
              Reliability (IEEE Std 802.1CB-2017)", 2017,
              <http://standards.ieee.org/about/get/>.

   [IEEEP8021CBdb]
              Mangin, C., "Extended -— Amendment: Extended Stream identification functions", Identification
              Functions", IEEE P802.1CBdb /D1.0 P802.1CBdb, September 2020,
              <http://www.ieee802.org/1/files/private/db-drafts/d1/802-
              1CBdb-d1-0.pdf>. / D1.3, April 2021,
              <https://1.ieee802.org/tsn/802-1cbdb/>.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031,
              DOI 10.17487/RFC3031, January 2001,
              <https://www.rfc-editor.org/info/rfc3031>.

   [RFC8655]  Finn, N., Thubert, P., Varga, B., and J. Farkas,
              "Deterministic Networking Architecture", RFC 8655,
              DOI 10.17487/RFC8655, October 2019,
              <https://www.rfc-editor.org/info/rfc8655>.

   [RFC8964]  Varga, B., Ed., Farkas, J., Berger, L., Malis, A., Bryant,
              S., and J. Korhonen, "Deterministic Networking (DetNet)
              Data Plane: MPLS", RFC 8964, DOI 10.17487/RFC8964, January
              2021, <https://www.rfc-editor.org/info/rfc8964>.

9.2.

8.2.  Informative References

   [I-D.ietf-detnet-security]

   [DETNET-SECURITY]
              Grossman, E., Mizrahi, T., and A. J. Hacker,
              "Deterministic Networking (DetNet) Security
              Considerations", draft-ietf-
              detnet-security-13 (work Work in progress), December 2020. Progress, Internet-Draft, draft-
              ietf-detnet-security-16, 2 March 2021,
              <https://tools.ietf.org/html/draft-ietf-detnet-security-
              16>.

   [IEEE802.1AE-2018]
              IEEE Standards Association,
              IEEE, "IEEE Standard for Local and metropolitan area
              networks-Media Access Control (MAC) Security", IEEE Std 802.1AE-2018 MAC
              Security (MACsec)",
              802.1AE-2018, DOI 10.1109/IEEESTD.2018.8585421, December
              2018, <https://ieeexplore.ieee.org/document/8585421>.

   [IEEE8021Q]
              IEEE 802.1, "Standard
              IEEE, "IEEE Standard for Local and metropolitan area
              networks--Bridges and Bridged Networks (IEEE Networks", IEEE Std 802.1Q-
              2018)",
              2018, <http://standards.ieee.org/about/get/>. DOI 10.1109/IEEESTD.2018.8403927, July 2018,
              <https://ieeexplore.ieee.org/document/8403927/>.

   [IEEEP8021CBcv]
              Kehrer, S., "FRER
              IEEE 802.1, "Draft Standard for Local and metropolitan
              area networks -- Frame Replication and Elimination for
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Acknowledgements

   The authors wish to thank Norman Finn, Lou Berger, Craig Gunther,
   Christophe Mangin, and Jouni Korhonen for their various contributions
   to this work.

Authors' Addresses

   Balazs

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

   Email: balazs.a.varga@ericsson.com

   Janos

   János Farkas
   Ericsson
   Budapest
   Magyar Tudosok krt. 11.
   Budapest
   1117
   Hungary

   Email: janos.farkas@ericsson.com

   Andrew G. Malis
   Malis Consulting

   Email: agmalis@gmail.com

   Stewart Bryant
   Futurewei Technologies

   Email: stewart.bryant@gmail.com sb@stewartbryant.com