    Internet Engineering Task Force (IETF)                        S. Boutros
    Request for Comments: 8214                                        VMware
    Category: Standards Track                                     A. Sajassi
    ISSN: 2070-1721                                                 S. Salam
                                                                       Cisco
                                                                    J. Drake
                                                            Juniper Networks
                                                                  J. Rabadan
                                                                       Nokia
                                                                 August 2017

              Virtual Private Wire Service Support in Ethernet VPN

    Abstract

       This document describes how Ethernet VPN (EVPN) can be used to
       support the Virtual Private Wire Service (VPWS) in MPLS/IP networks.
       EVPN accomplishes the following for VPWS: provides Single-Active as
       well as All-Active multihoming with flow-based load-balancing,
       eliminates the need for Pseudowire (PW) signaling, and provides fast
       protection convergence upon node or link failure.

    Status of This Memo

       This is an Internet Standards Track document.

       This document is a product of the Internet Engineering Task Force
       (IETF).  It represents the consensus of the IETF community.  It has
       received public review and has been approved for publication by the
       Internet Engineering Steering Group (IESG).  Further information on
       Internet Standards is available in Section 2 of RFC 7841.

       Information about the current status of this document, any errata,
       and how to provide feedback on it may be obtained at
       https://www.rfc-editor.org/info/rfc8214.

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    Copyright Notice

       Copyright (c) 2017 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.

    Table of Contents

       1. Introduction ....................................................3
          1.1. Terminology ................................................5
       2. Service Interface ...............................................6
          2.1. VLAN-Based Service Interface ...............................6
          2.2. VLAN Bundle Service Interface ..............................7
               2.2.1. Port-Based Service Interface ........................7
          2.3. VLAN-Aware Bundle Service Interface ........................7
       3. BGP Extensions ..................................................7
          3.1. EVPN Layer 2 Attributes Extended Community .................8
       4. Operation ......................................................10
       5. EVPN Comparison to PW Signaling ................................11
       6. Failure Scenarios ..............................................12
          6.1. Single-Homed CEs ..........................................12
          6.2. Multihomed CEs ............................................12
       7. Security Considerations ........................................13
       8. IANA Considerations ............................................13
       9. References .....................................................13
          9.1. Normative References ......................................13
          9.2. Informative References ....................................14
       Acknowledgements ..................................................16
       Contributors ......................................................16
       Authors' Addresses ................................................17

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    1.  Introduction

       This document describes how EVPN can be used to support VPWS in
       MPLS/IP networks.  The use of EVPN mechanisms for VPWS (EVPN-VPWS)
       brings the benefits of EVPN to Point-to-Point (P2P) services.  These
       benefits include Single-Active redundancy as well as All-Active
       redundancy with flow-based load-balancing.  Furthermore, the use of
       EVPN for VPWS eliminates the need for the traditional way of PW
       signaling for P2P Ethernet services, as described in Section 4.

       [RFC7432] provides the ability to forward customer traffic to/from a
       given customer Attachment Circuit (AC), without any Media Access
       Control (MAC) lookup.  This capability is ideal in providing P2P
       services (aka VPWS services).  [MEF] defines the Ethernet Virtual
       Private Line (EVPL) service as a P2P service between a pair of ACs
       (designated by VLANs) and the Ethernet Private Line (EPL) service,
       in which all traffic flows are between a single pair of ports that,
       in EVPN terminology, would mean a single pair of Ethernet Segments
       ES(es).  EVPL can be considered as a VPWS with only two ACs.  In
       delivering an EVPL service, the traffic-forwarding capability of EVPN
       is based on the exchange of a pair of Ethernet Auto-Discovery (A-D)
       routes, whereas for more general VPWS as per [RFC4664], the
       traffic-forwarding capability of EVPN is based on the exchange of a
       group of Ethernet A-D routes (one Ethernet A-D route per AC/ES).  In
       a VPWS service, the traffic from an originating Ethernet Segment can
       be forwarded only to a single destination Ethernet Segment; hence, no
       MAC lookup is needed, and the MPLS label associated with the per-EVPN
       instance (EVI) Ethernet A-D route can be used in forwarding user
       traffic to the destination AC.

       For both EPL and EVPL services, a specific VPWS service instance is
       identified by a pair of per-EVI Ethernet A-D routes that together
       identify the VPWS service instance endpoints and the VPWS service
       instance.  In the control plane, the VPWS service instance is
       identified using the VPWS service instance identifiers advertised by
       each Provider Edge (PE) node.  In the data plane, the value of the
       MPLS label advertised by one PE is used by the other PE to send
       traffic for that VPWS service instance.  As with the Ethernet Tag in
       standard EVPN, the VPWS service instance identifier has uniqueness
       within an EVPN instance.

       For EVPN routes, the Ethernet Tag IDs are set to zero for port-based,
       VLAN-based, and VLAN bundle interface mode and set to non-zero
       Ethernet Tag IDs for VLAN-aware bundle mode.  Conversely, for
       EVPN-VPWS, the Ethernet Tag ID in the Ethernet A-D route MUST be set
       to a non-zero value for all four service interface types.

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    RFC 8214                  VPWS Support in EVPN               August 2017

       In terms of route advertisement and MPLS label lookup behavior,
       EVPN-VPWS resembles the VLAN-aware bundle mode of [RFC7432] such that
       when a PE advertises a per-EVI Ethernet A-D route, the VPWS service
       instance serves as a 32-bit normalized Ethernet Tag ID.  The value of
       the MPLS label in this route represents both the EVI and the VPWS
       service instance, so that upon receiving an MPLS-encapsulated packet,
       the disposition PE can identify the egress AC from the MPLS label and
       subsequently perform any required tag translation.  For the EVPL
       service, the Ethernet frames transported over an MPLS/IP network
       SHOULD remain tagged with the originating VLAN ID (VID), and any VID
       translation MUST be performed at the disposition PE.  For the EPL
       service, the Ethernet frames are transported as is, and the tags
       are not altered.

       The MPLS label value in the Ethernet A-D route can be set to the
       Virtual Extensible LAN (VXLAN) Network Identifier (VNI) for VXLAN
       encapsulation as per [RFC7348], and this VNI will have a local scope
       per PE and may also be equal to the VPWS service instance identifier
       set in the Ethernet A-D route.  When using VXLAN encapsulation, the
       BGP Encapsulation extended community is included in the Ethernet A-D
       route as described in [EVPN-OVERLAY].  The VNI is like the MPLS label
       that will be set in the tunnel header used to tunnel Ethernet packets
       from all the service interface types defined in Section 2.  The
       EVPN-VPWS techniques defined in this document have no dependency on
       the tunneling technology.

       The Ethernet Segment Identifier encoded in the Ethernet A-D per-EVI
       route is not used to identify the service.  However, it can be used
       for flow-based load-balancing and mass withdraw functions as per the
       [RFC7432] baseline.

       As with standard EVPN, the Ethernet A-D per-ES route is used for fast
       convergence upon link or node failure.  The Ethernet Segment route is
       used for auto-discovery of the PEs attached to a given multihomed
       Customer Edge node (CE) and to synchronize state between them.

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    1.1.  Terminology

       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.

       EVPN: Ethernet VPN.

       MAC: Media Access Control.

       MPLS: Multiprotocol Label Switching.

       OAM: Operations, Administration, and Maintenance.

       PE: Provider Edge Node.

       AS: Autonomous System.

       ASBR: Autonomous System Border Router.

       CE: Customer Edge device (e.g., host, router, or switch).

       EVPL: Ethernet Virtual Private Line.

       EPL: Ethernet Private Line.

       EP-LAN: Ethernet Private LAN.

       EVP-LAN: Ethernet Virtual Private LAN.

       S-VLAN: Service VLAN identifier.

       C-VLAN: Customer VLAN identifier.

       VID: VLAN ID.

       VPWS: Virtual Private Wire Service.

       EVI: EVPN Instance.

       P2P: Point to Point.

       VXLAN: Virtual Extensible LAN.

       DF: Designated Forwarder.

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       L2: Layer 2.

       MTU: Maximum Transmission Unit.

       eBGP: External Border Gateway Protocol.

       iBGP: Internal Border Gateway Protocol.

       ES: "Ethernet Segment" on a PE refers to the link attached to it.
          This link can be part of a set of links attached to different PEs
          in multihomed cases or could be a single link in single-homed
          cases.

       ESI: Ethernet Segment Identifier.

       Single-Active Mode: When a device or a network is multihomed to two
          or more PEs and when only a single PE in such a redundancy group
          can forward traffic to/from the multihomed device or network for a
          given VLAN, then such multihoming or redundancy is referred to as
          "Single-Active".

       All-Active Mode: When a device is multihomed to two or more PEs and
          when all PEs in such a redundancy group can forward traffic
          to/from the multihomed device for a given VLAN, then such
          multihoming or redundancy is referred to as "All-Active".

       VPWS Service Instance: A VPWS service instance is represented by a
          pair of EVPN service labels associated with a pair of endpoints.
          Each label is downstream-assigned and advertised by the
          disposition PE through an Ethernet A-D per-EVI route.  The
          downstream label identifies the endpoint on the disposition PE.  A
          VPWS service instance can be associated with only one VPWS service
          identifier.

    2.  Service Interface

    2.1.  VLAN-Based Service Interface

       With this service interface, a VPWS instance identifier corresponds
       to only a single VLAN on a specific interface.  Therefore, there is a
       one-to-one mapping between a VID on this interface and the VPWS
       service instance identifier.  The PE provides the cross-connect
       functionality between an MPLS Label Switched Path (LSP) identified by
       the VPWS service instance identifier and a specific <port, VLAN>.  If
       the VLAN is represented by different VIDs on different PEs and
       different ES(es) (e.g., a different VID per Ethernet Segment per PE),
       then each PE needs to perform VID translation for frames destined to
       its Ethernet Segment.  In such scenarios, the Ethernet frames

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       transported over an MPLS/IP network SHOULD remain tagged with the
       originating VID, and a VID translation MUST be supported in the data
       path and MUST be performed on the disposition PE.

    2.2.  VLAN Bundle Service Interface

       With this service interface, a VPWS service instance identifier
       corresponds to multiple VLANs on a specific interface.  The PE
       provides the cross-connect functionality between the MPLS label
       identified by the VPWS service instance identifier and a group of
       VLANs on a specific interface.  For this service interface, each VLAN
       is presented by a single VID, which means that no VLAN translation is
       allowed.  The receiving PE can direct the traffic, based on the EVPN
       label alone, to a specific port.  The transmitting PE can
       cross-connect traffic from a group of VLANs on a specific port to the
       MPLS label.  The MPLS-encapsulated frames MUST remain tagged with the
       originating VID.

    2.2.1.  Port-Based Service Interface

       This service interface is a special case of the VLAN bundle service
       interface, where all of the VLANs on the port are mapped to the same
       VPWS service instance identifier.  The procedures are identical to
       those described in Section 2.2.

    2.3.  VLAN-Aware Bundle Service Interface

       Contrary to EVPN, in EVPN-VPWS this service interface maps to a
       VLAN-based service interface (defined in Section 2.1); thus, this
       service interface is not used in EVPN-VPWS.  In other words, if one
       tries to define data-plane and control-plane behavior for this
       service interface, one would realize that it is the same as that of
       the VLAN-based service.

    3.  BGP Extensions

       This document specifies the use of the per-EVI Ethernet A-D route to
       signal VPWS services.  The ESI field is set to the customer ES, and
       the 32-bit Ethernet Tag ID field MUST be set to the VPWS service
       instance identifier value.  The VPWS service instance identifier
       value MAY be set to a 24-bit value, and when a 24-bit value is used,
       it MUST be right-aligned.  For both EPL and EVPL services using a
       given VPWS service instance, the pair of PEs instantiating that VPWS
       service instance will each advertise a per-EVI Ethernet A-D route
       with its VPWS service instance identifier and will each be configured
       with the other PE's VPWS service instance identifier.  When each PE

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       has received the other PE's per-EVI Ethernet A-D route, the VPWS
       service instance is instantiated.  It should be noted that the same
       VPWS service instance identifier may be configured on both PEs.

       The Route Target (RT) extended community with which the per-EVI
       Ethernet A-D route is tagged identifies the EVPN instance in which
       the VPWS service instance is configured.  It is the operator's choice
       as to how many and which VPWS service instances are configured in a
       given EVPN instance.  However, a given EVPN instance MUST NOT be
       configured with both VPWS service instances and standard EVPN
       multipoint services.

    3.1.  EVPN Layer 2 Attributes Extended Community

       This document defines a new extended community [RFC4360], to be
       included with per-EVI Ethernet A-D routes.  This attribute is
       mandatory if multihoming is enabled.

                   +-------------------------------------------+
                   |  Type (0x06) / Sub-type (0x04) (2 octets) |
                   +-------------------------------------------+
                   |  Control Flags  (2 octets)                |
                   +-------------------------------------------+
                   |  L2 MTU (2 octets)                        |
                   +-------------------------------------------+
                   |  Reserved (2 octets)                      |
                   +-------------------------------------------+

               Figure 1: EVPN Layer 2 Attributes Extended Community

                0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
               |   MBZ                   |C|P|B|  (MBZ = MUST Be Zero)
               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 2: EVPN Layer 2 Attributes Control Flags

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             The following bits in Control Flags are defined; the remaining
             bits MUST be set to zero when sending and MUST be ignored when
             receiving this community.

             Name     Meaning
             ---------------------------------------------------------------
             P        If set to 1 in multihoming Single-Active scenarios,
                      this flag indicates that the advertising PE is the
                      primary PE.  MUST be set to 1 for multihoming
                      All-Active scenarios by all active PE(s).

             B        If set to 1 in multihoming Single-Active scenarios,
                      this flag indicates that the advertising PE is the
                      backup PE.

             C        If set to 1, a control word [RFC4448] MUST be present
                      when sending EVPN packets to this PE.  It is
                      recommended that the control word be included in the
                      absence of an entropy label [RFC6790].

       L2 MTU is a 2-octet value indicating the MTU in bytes.

       A received L2 MTU of zero means that no MTU checking against the
       local MTU is needed.  A received non-zero MTU MUST be checked against
       the local MTU, and if there is a mismatch, the local PE MUST NOT add
       the remote PE as the EVPN destination for the corresponding VPWS
       service instance.

       The usage of the per-ES Ethernet A-D route is unchanged from its
       usage in [RFC7432], i.e., the "Single-Active" bit in the flags of the
       ESI Label extended community will indicate if Single-Active or
       All-Active redundancy is used for this ES.

       In a multihoming All-Active scenario, there is no Designated
       Forwarder (DF) election, and all the PEs in the ES that are active
       and ready to forward traffic to/from the CE will set the P Flag.  A
       remote PE will do per-flow load-balancing to the PEs that set the
       P Flag for the same Ethernet Tag and ESI.  The B Flag in
       Control Flags SHOULD NOT be set in the multihoming All-Active
       scenario and MUST be ignored by receiving PE(s) if set.

       In a multihoming Single-Active scenario for a given VPWS service
       instance, the DF election should result in the primary-elected PE for
       the VPWS service instance advertising the P Flag set and the B Flag
       clear, the backup-elected PE should advertise the P Flag clear and
       the B Flag set, and the rest of the PEs in the same ES should signal
       both the P Flag and the B Flag clear.  When the primary PE/ES fails,
       the primary PE will withdraw the associated Ethernet A-D routes for

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       the VPWS service instance from the remote PE, and the remote PE
       should then send traffic associated with the VPWS instance to the
       backup PE.  DF re-election will happen between the PE(s) in the same
       ES, and there will be a newly elected primary PE and newly elected
       backup PE that will signal the P and B Flags as described.  A remote
       PE SHOULD receive the P Flag set from only one primary PE and the B
       Flag set from only one backup PE.  However, during transient
       situations, a remote PE receiving a P Flag set from more than one PE
       will select the last advertising PE as the primary PE when forwarding
       traffic.  A remote PE receiving a B Flag set from more than one PE
       will select the last advertising PE as the backup PE.  A remote PE
       MUST receive a P Flag set from at least one PE before forwarding
       traffic.

       If a network uses entropy labels per [RFC6790], then the C Flag
       MUST NOT be set, and the control word MUST NOT be used when sending
       EVPN-encapsulated packets over a P2P LSP.

    4.  Operation

       The following figure shows an example of a P2P service deployed
       with EVPN.

              Ethernet                                          Ethernet
              Native   |<--------- EVPN Instance ----------->|  Native
              Service  |                                     |  Service
              (AC)     |     |<-PSN1->|       |<-PSN2->|     |  (AC)
                 |     V     V        V       V        V     V  |
                 |     +-----+      +-----+  +-----+   +-----+  |
          +----+ |     | PE1 |======|ASBR1|==|ASBR2|===| PE3 |  |    +----+
          |    |-------+-----+      +-----+  +-----+   +-----+-------|    |
          | CE1| |                                              |    |CE2 |
          |    |-------+-----+      +-----+  +-----+   +-----+-------|    |
          +----+ |     | PE2 |======|ASBR3|==|ASBR4|===| PE4 |  |    +----+
               ^       +-----+      +-----+  +-----+   +-----+          ^
               |   Provider Edge 1        ^        Provider Edge 2      |
               |                          |                             |
               |                          |                             |
               |              EVPN Inter-provider point                 |
               |                                                        |
               |<---------------- Emulated Service -------------------->|

                       Figure 3: EVPN-VPWS Deployment Model

       iBGP sessions are established between PE1, PE2, ASBR1, and ASBR3,
       possibly via a BGP route reflector.  Similarly, iBGP sessions are
       established among PE3, PE4, ASBR2, and ASBR4.  eBGP sessions are
       established among ASBR1, ASBR2, ASBR3, and ASBR4.

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       All PEs and ASBRs are enabled for the EVPN Subsequent Address Family
       Identifier (SAFI) and exchange per-EVI Ethernet A-D routes, one route
       per VPWS service instance.  For inter-AS option B, the ASBRs
       re-advertise these routes with the NEXT_HOP attribute set to their IP
       addresses as per [RFC4271].  The link between the CE and the PE is
       either a C-tagged or S-tagged interface, as described in [802.1Q],
       that can carry a single VLAN tag or two nested VLAN tags, and it is
       configured as a trunk with multiple VLANs, one per VPWS service
       instance.  It should be noted that the VLAN ID used by the customer
       at either end of a VPWS service instance to identify that service
       instance may be different, and EVPN doesn't perform that translation
       between the two values.  Rather, the MPLS label will identify the
       VPWS service instance, and if translation is needed, it should be
       done by the Ethernet interface for each service.

       For a single-homed CE, in an advertised per-EVI Ethernet A-D route,
       the ESI field is set to zero and the Ethernet Tag ID is set to the
       VPWS service instance identifier that identifies the EVPL or EPL
       service.

       For a multihomed CE, in an advertised per-EVI Ethernet A-D route, the
       ESI field is set to the CE's ESI and the Ethernet Tag ID is set to
       the VPWS service instance identifier, which MUST have the same value
       on all PEs attached to that ES.  This allows an ingress PE in a
       multihoming All-Active scenario to perform flow-based load-balancing
       of traffic flows to all of the PEs attached to that ES.  In all
       cases, traffic follows the transport paths, which may be asymmetric.

       Either (1) the VPWS service instance identifier encoded in the
       Ethernet Tag ID in an advertised per-EVI Ethernet A-D route MUST be
       unique across all ASes or (2) an ASBR needs to perform a translation
       when the per-EVI Ethernet A-D route is re-advertised by the ASBR from
       one AS to the other AS.

       A per-ES Ethernet A-D route can be used for mass withdraw to withdraw
       all per-EVI Ethernet A-D routes associated with the multihomed site
       on a given PE.

    5.  EVPN Comparison to PW Signaling

       In EVPN, service endpoint discovery and label signaling are done
       concurrently using BGP, whereas with VPWS based on [RFC4448], label
       signaling is done via LDP and service endpoint discovery is either
       through manual provisioning or through BGP.

       In existing implementations of VPWS using PWs, redundancy is limited
       to Single-Active mode, while with EVPN implementations of VPWS, both
       Single-Active and All-Active redundancy modes can be supported.

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       In existing implementations with PWs, backup PWs are not used to
       carry traffic, while with EVPN, traffic can be load-balanced among
       different PEs multihomed to a single CE.

       Upon link or node failure, EVPN can trigger failover with the
       withdrawal of a single BGP route per EVPL service or multiple EVPL
       services, whereas with VPWS PW redundancy, the failover sequence
       requires the exchange of two control-plane messages: one message to
       deactivate the group of primary PWs and a second message to activate
       the group of backup PWs associated with the access link.

       Finally, EVPN may employ data-plane egress link protection mechanisms
       not available in VPWS.  This can be done by the primary PE (on local
       AC down) using the label advertised in the per-EVI Ethernet A-D route
       by the backup PE to encapsulate the traffic and direct it to the
       backup PE.

    6.  Failure Scenarios

       On a link or port failure between the CE and the PE for both
       single-homed and multihomed CEs, unlike [RFC7432], the PE MUST
       withdraw all the associated Ethernet A-D routes for the VPWS service
       instances on the failed port or link.

    6.1.  Single-Homed CEs

       Unlike [RFC7432], EVPN-VPWS uses Ethernet A-D route advertisements
       for single-homed Ethernet Segments.  Therefore, upon a link/port
       failure of a given single-homed Ethernet Segment, the PE MUST
       withdraw the associated per-EVI Ethernet A-D routes.

    6.2.  Multihomed CEs

       For a faster convergence in multihomed scenarios with either
       Single-Active redundancy or All-Active redundancy, a mass withdraw
       technique is used.  A PE previously advertising a per-ES Ethernet A-D
       route can withdraw this route by signaling to the remote PEs to
       switch all the VPWS service instances associated with this multihomed
       ES to the backup PE.

       Just like RFC 7432, the Ethernet A-D per-EVI route MUST NOT be used
       for traffic forwarding by a remote PE until it also receives the
       associated set of Ethernet A-D per-ES routes.

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    7.  Security Considerations

       The mechanisms in this document use the EVPN control plane as defined
       in [RFC7432].  The security considerations described in [RFC7432] are
       equally applicable.

       This document uses MPLS and IP-based tunnel technologies to support
       data-plane transport.  The security considerations described in
       [RFC7432] and in [EVPN-OVERLAY] are equally applicable.

    8.  IANA Considerations

       IANA has allocated the following EVPN Extended Community sub-type:

          Sub-Type Value     Name                        Reference
          --------------------------------------------------------
          0x04               EVPN Layer 2 Attributes     RFC 8214

       This document creates a registry called "EVPN Layer 2 Attributes
       Control Flags".  New registrations will be made through the
       "RFC Required" procedure defined in [RFC8126].

       Initial registrations are as follows:

            P      Advertising PE is the primary PE.
            B      Advertising PE is the backup PE.
            C      Control word [RFC4448] MUST be present.

    9.  References

    9.1.  Normative References

       [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>.

       [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>.

       [RFC7432]  Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
                  Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
                  Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432,
                  February 2015, <https://www.rfc-editor.org/info/rfc7432>.

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    RFC 8214                  VPWS Support in EVPN               August 2017

       [RFC4448]  Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron,
                  "Encapsulation Methods for Transport of Ethernet over MPLS
                  Networks", RFC 4448, DOI 10.17487/RFC4448, April 2006,
                  <https://www.rfc-editor.org/info/rfc4448>.

       [RFC6790]  Kompella, K., Drake, J., Amante, S., Henderickx, W., and
                  L. Yong, "The Use of Entropy Labels in MPLS Forwarding",
                  RFC 6790, DOI 10.17487/RFC6790, November 2012,
                  <https://www.rfc-editor.org/info/rfc6790>.

       [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
                  Border Gateway Protocol 4 (BGP-4)", RFC 4271,
                  DOI 10.17487/RFC4271, January 2006,
                  <https://www.rfc-editor.org/info/rfc4271>.

       [RFC4360]  Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
                  Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
                  February 2006, <https://www.rfc-editor.org/info/rfc4360>.

       [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
                  Writing an IANA Considerations Section in RFCs", BCP 26,
                  RFC 8126, DOI 10.17487/RFC8126, June 2017,
                  <https://www.rfc-editor.org/info/rfc8126>.

       [RFC7348]  Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
                  L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
                  eXtensible Local Area Network (VXLAN): A Framework for
                  Overlaying Virtualized Layer 2 Networks over Layer 3
                  Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
                  <https://www.rfc-editor.org/info/rfc7348>.

    9.2.  Informative References

       [MEF]      Metro Ethernet Forum, "EVC Ethernet Services Definitions
                  Phase 3", Technical Specification MEF 6.2, August 2014,
                  <https://www.mef.net/Assets/Technical_Specifications/
                  PDF/MEF_6.2.pdf>.

       [RFC4664]  Andersson, L., Ed., and E. Rosen, Ed., "Framework for
                  Layer 2 Virtual Private Networks (L2VPNs)", RFC 4664,
                  DOI 10.17487/RFC4664, September 2006,
                  <https://www.rfc-editor.org/info/rfc4664>.

    Boutros, et al.              Standards Track                   [Page 14]

    RFC 8214                  VPWS Support in EVPN               August 2017

       [EVPN-OVERLAY]
                  Sajassi, A., Ed., Drake, J., Ed., Bitar, N., Shekhar, R.,
                  Uttaro, J., and W. Henderickx, "A Network Virtualization
                  Overlay Solution using EVPN", Work in Progress,
                  draft-ietf-bess-evpn-overlay-08, March 2017.

       [802.1Q]   IEEE, "IEEE Standard for Local and metropolitan area
                  networks -- Media Access Control (MAC) Bridges and Virtual
                  Bridge Local Area Networks", IEEE Std 802.1Q-2011,
                  DOI 10.1109/IEEESTD.2011.6009146.

    Boutros, et al.              Standards Track                   [Page 15]

    RFC 8214                  VPWS Support in EVPN               August 2017

    Acknowledgements

       The authors would like to acknowledge Jeffrey Zhang, Wen Lin, Nitin
       Singh, Senthil Sathappan, Vinod Prabhu, Himanshu Shah, Iftekhar
       Hussain, Alvaro Retana, and Acee Lindem for their feedback and
       contributions to this document.

    Contributors

       In addition to the authors listed on the front page, the following
       coauthors have also contributed to this document:

       Jeff Tantsura
       Individual
       Email: jefftant@gmail.com

       Dirk Steinberg
       Steinberg Consulting
       Email: dws@steinbergnet.net

       Patrice Brissette
       Cisco Systems
       Email: pbrisset@cisco.com

       Thomas Beckhaus
       Deutsche Telecom
       Email: Thomas.Beckhaus@telekom.de

       Ryan Bickhart
       Juniper Networks
       Email: rbickhart@juniper.net

       Daniel Voyer
       Bell Canada

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    RFC 8214                  VPWS Support in EVPN               August 2017

    Authors' Addresses

       Sami Boutros
       VMware, Inc.

       Email: sboutros@vmware.com

       Ali Sajassi
       Cisco Systems

       Email: sajassi@cisco.com

       Samer Salam
       Cisco Systems

       Email: ssalam@cisco.com

       John Drake
       Juniper Networks

       Email: jdrake@juniper.net

       Jorge Rabadan
       Nokia

       Email: jorge.rabadan@nokia.com

    Boutros, et al.              Standards Track                   [Page 17]