Network Working Group                                          R. Parekh
Internet-Draft                                               C. Filsfils
Intended status: Standards Track                        A. Venkateswaran
Expires: June 5, 2021                                Cisco Systems, Inc.
                                                              H. Bidgoli
                                                                   Nokia
                                                                D. Voyer
                                                             Bell Canada
                                                                Z. Zhang
                                                        Juniper Networks
                                                        December 2, 2020


  Multicast and Ethernet VPN with Segment Routing Point-to-Multipoint
                                 Trees
                  draft-ietf-bess-mvpn-evpn-sr-p2mp-01

Abstract

   A Point-to-Multipoint (P2MP) Tree in a Segment Routing domain
   efficiently carries traffic from a Root to a set of Leaves.  This
   document describes extensions to BGP encodings and procedures for
   P2MP trees used in BGP/MPLS IP VPNs and Ethernet VPNs.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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 June 5, 2021.





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Copyright Notice

   Copyright (c) 2020 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
   2.  SR P2MP P-Tunnels . . . . . . . . . . . . . . . . . . . . . .   3
   3.  PMSI Tunnel Attribute for SR P2MP . . . . . . . . . . . . . .   4
     3.1.  MPLS Label  . . . . . . . . . . . . . . . . . . . . . . .   5
       3.1.1.  SR MPLS . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  MVPN Auto-Discovery and Binding Procedures  . . . . . . . . .   5
     4.1.  Intra-AS I-PMSI . . . . . . . . . . . . . . . . . . . . .   5
       4.1.1.  Originating Intra-AS I-PMSI routes  . . . . . . . . .   5
       4.1.2.  Receiving Intra-AS I-PMSI A-D routes  . . . . . . . .   6
     4.2.  Using S-PMSIs for binding customer flows to P2MP Segments   7
       4.2.1.  Originating S-PMSI A-D routes . . . . . . . . . . . .   7
       4.2.2.  Receiving S-PMSI A-D routes . . . . . . . . . . . . .   8
     4.3.  Inter-AS P-tunnels using P2MP Segments  . . . . . . . . .   8
       4.3.1.  Advertising Inter-AS I-PMSI routes into iBGP  . . . .   8
       4.3.2.  Receiving Inter-AS I-PMSI A-D routes in iBGP  . . . .   8
     4.4.  Leaf A-D routes for P2MP Segment Leaf Discovery . . . . .   9
       4.4.1.  Originating Leaf A-D routes . . . . . . . . . . . . .   9
       4.4.2.  Receiving Leaf A-D routes . . . . . . . . . . . . . .   9
   5.  Dampening of MVPN routes  . . . . . . . . . . . . . . . . . .   9
   6.  SR P2MP Trees for EVPN  . . . . . . . . . . . . . . . . . . .  10
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  11
   10. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  11
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     11.2.  Informative References . . . . . . . . . . . . . . . . .  12
     11.3.  URIs . . . . . . . . . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14





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1.  Introduction

   Multicast in MPLS/BGP IP VPNs [RFC6513] and BGP Encodings and
   Procedures for Multicast in MPLS/BGP IP VPNs [RFC6514] specify
   procedures that allow a Service Provider to provide Multicast VPN
   (MVPN) service to its customers.  Multicast traffic from a customer
   is tunneled across the service provider network over Provider Tunnels
   (P-Tunnels).  P-tunnels can be instantiated via different
   technologies.  A service provider network that uses Segment Routing
   can use a Point-to-Multipoint (SR P2MP) tree
   [I-D.ietf-pim-sr-p2mp-policy] to instantiate P-Tunnels for MVPN.

   In a Segment Routing network, a P2MP tree allows efficient delivery
   of traffic from a Root to set of Leaf nodes.  A SR P2MP tree is
   defined by a SR P2MP Policy and instantiated via a PCE.  A P2MP
   Policy consists of a Root, a Set of Leaf Nodes and a set of candidate
   paths with optional set of constraints and/or optimization objectives
   to be satisfied by the P2MP tree.  A unique Identifier, called Tree-
   SID, is associated with a P2MP tree.  This Tree-SID can be an MPLS
   label or an IPv6 address.

   This document describes extensions to BGP Auto-Discovery procedures
   specified in RFC 6514 for SR P2MP P-Tunnels.  Use of PIM for Auto-
   Discovery is outside scope of this document.  Support for customer
   BIDIR-PIM is outside the scope of this document.

   For BGP MPLS Ethernet VPN specified in [RFC7432] and extensions to
   this document, P-Tunnels are advertised for handling multi-
   destination traffic.  These P-tunnels can be realized by SR P2MP
   trees.  SRv6 P2MP trees can also be used to support Multicast in
   Network Virtualization over Layer 3 [RFC8293].

   The reader is expected to be familiar with concepts and terminology
   of RFC 6513, RFC 6514 and SR P2MP draft.

2.  SR P2MP P-Tunnels

   For MVPN or EVPN, Provider Edge(PE) routers steer customer traffic
   into a P-Tunnel that can be instantiated by SR P2MP tree.  A SR P2MP
   tree is defined by a SR P2MP policy [I-D.ietf-pim-sr-p2mp-policy].

   SR P2MP P-tunnel can be instantiated by either SR-MPLS or SRv6 P2MP
   trees.  Details for SRv6 P2MP trees will be added in future revision
   of this document.

   Given a SR P2MP policy, a PCE computes and instantiates the SR P2MP
   tree on the nodes that are part of the tree using Replication
   segments and Tree-SID which a unique identifier for the tree



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   [I-D.ietf-spring-sr-replication-segment].  A Replication segment can
   be initiated by various methods (BGP, PCEP, others) which are outside
   the scope of this document.

   A PCE provides conceptual APIs, listed below, to define and modify SR
   P2MP policies SR P2MP Policy Section 4.1.1 [1].  These APIs are
   invoked by a PCC, which is the root of P2MP tree, using various
   methods (BGP, PCEP, etc.) which are outside the scope of this
   document.

      CreatePolicy: CreateSRP2MPPolicy<Root, Tree-ID>

      DeletePolicy: DeleteSRP2MPPolicy<Root, Tree-ID>

      UpdateLeafSet: SRP2MPPolicyLeafSetModify<Root, Tree-ID, {Leaf
      Set}>

   The Root of a P2MP tree imposes the Tree-SID to steer the customer
   payload into the P2MP tree.  Provider (P) routers replicate customer
   payload, using Replication segments, towards the Leaf nodes of the
   P2MP tree.  Leaf nodes of the P2MP tree deliver the customer payload
   after dispoing the Tree-SID.

3.  PMSI Tunnel Attribute for SR P2MP

   A PMSI Tunnel Attribute (PTA) is defined in RFC 6514 to identify the
   P-Tunnel that is used to instantiate a Provider Multicast Service
   Interface (PMSI).  The PTA is carried in Intra-AS I-PMSI, Inter-AS
   I-PMSI, Selective PMSI, and Leaf Auto-Discovery routes.

   A P2MP tree PTA is constructed as follows:

   o  Tunnel Type: The codepoint is set to [[CREF1: TBD]]for SR P2MP
      tree from the "P-Multicast Service Interface Tunnel (PMSI Tunnel)
      Tunnel Types" registry.

   o  Flags: See Section 4 for use of "Leaf Info Required bit".

   o  MPLS Label: See Section 3.1

   o  Tunnel Identifier: The SR P2MP P-tunnel is identified by <Tree-ID,
      Root> where,

      *  Tree-ID is a 32-bit unsigned value that identifies a unique
         P2MP tree at a Root..






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      *  Root is an IP address identifying the Root of a P2MP tree.
         This can be either an IPv4 or IPv6 address and can be inferred
         from the PTA length.

   When a P-Tunnel is non-segmented, the PTA is created by PE router at
   the Root of a SR P2MP tree.  For segmented P-tunnels, each segment
   can be instantiated by a different technology.  If a segment is
   instantiated using P2MP tree, the router at the root of a P2MP tree
   creates the PTA.

3.1.  MPLS Label

   [RFC6514] allows a PE to aggregate two or more MVPNs onto one
   P-tunnel by advertising the same P-tunnel in PTA of Auto-Discovery
   routes of different MVPNs.  This section specifies how the "MPLS
   Label" field of PTA is filled to provide a context bound to a
   specific MPVN.  For EVPN considerations, see SR P2MP Trees for EVPN
   section.

3.1.1.  SR MPLS

   When a SR P2MP P-tunnel, shared across different MVPNs, is
   instantiated in a SR MPLS domain [RFC8660], "MPLS Field" of a PTA
   advertised in a Auto-Discovery route MUST contain an upstream-
   assigned MPLS label that the advertising PE has bound to the MVPN.

   When a customer payload is steered into a shared SR P2MP P-tunnel,
   this MPLS label MUST be imposed before the MPLS label representing
   the Tree-SID.

4.  MVPN Auto-Discovery and Binding Procedures

   RFC 6514 defines procedures for discovering PEs participating in a
   given MVPN and binding customer multicast flows to specific
   P-Tunnels.  This section specifies modifications to these procedures
   for SR P2MP P-Tunnels.

4.1.  Intra-AS I-PMSI

   Intra-AS I-PMSI A-D routes are exchanged to discover PEs
   participating in a MVPN within an AS, or across different ASes when
   non-segmented P-tunnels for inter-AS MVPNs.

4.1.1.  Originating Intra-AS I-PMSI routes

   RFC 6514 Section 9.1.1 [2] describes procedures for originating
   Intra-AS I-PMSI A-D routes.  For SR P2MP P-tunnels, these procedures
   remain unchanged except as described in the following paragraphs.



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   When a PE originates an Intra-AS I-PMSI A-D route with a PTA having
   SR P2MP P-tunnel Type, it MUST create a P2MP policy by invoking
   CreatePolicy API of the PCE.  When the PCE instantiates the P2MP tree
   on the PE, the Tree-SID MUST be imposed for customer flow(s) steered
   into the P2MP tree.  The Leaf nodes of P2MP tree are discovered using
   procedures described in Section 4.1.2.

   For a PE in "Receiver Sites set", condition (c) is modified to
   include P2MP tree i.e. such a PE MUST originate an Intra-AS I-PMSI
   A-D route when some PEs of the MVPN have VRFs that use SR P2MP tree
   but MUST NOT create a SR P2MP policy as described above.

   When a PE withdraws an Intra-AS I-PMSI A-D route, advertised with a
   PTA having SR P2MP P-tunnel Type, the Tree-SID imposition state at
   the PE MUST be removed.

   A PE MAY aggregate two or more Intra-AS I-PMSIs from different MVPNs
   onto the same SR P2MP P-tunnel.  When a PE withdraws the last Intra-
   AS I-PMSI A-D route, advertised with a PTA identifying a SR P2MP
   P-tunnel , it SHOULD remove the SR P2MP policy by invoking
   DeletePolicy API of the PCE.

4.1.2.  Receiving Intra-AS I-PMSI A-D routes

   Procedure for receiving Intra-AS I-PMSI A-D routes, as described in
   RFC 6514 Section 9.1.2 [3], remain unchanged for SR P2MP P-tunnels
   except as described in the following paragraphs.

   When a PE that advertises a SR P2MP P-tunnel in the PTA of its Intra-
   AS I-PMSI A-D route, imports an Intra-AS I-PMSI A-D route from some
   PE, it MUST add that PE as a Leaf node of the P2MP tree.  The
   Originating IP Address of the Intra-AS i-PMSI A-D route is used as
   the Leaf Address when invoking UpdateLeafSet API of the PCE.  This
   procedure MUST also be followed for all Intra-AS I-PMSI routes that
   are already imported when the PE advertises a SR P2MP P-tunnel in PTA
   of its Intra-AS I-PMSI A-D route.

   A PE that imports and processes an Intra-AS I-PMSI A-D route from
   another PE with PTA having SR P2MP P-Tunnel MUST program the Tree-SID
   of the P2MP tree identified in the PTA of the route for disposition.
   Note that an Intra-AS I-PMSI A-D route from another PE can be
   imported before the P2MP tree identified in the PTA of the route is
   instantiated by the PCEat the importing PE.  In such case, the PE
   MUST correctly program Tree-SID for disposition.  A PE in "Sender
   Sites set" MAY avoid programming the Tree-SID for disposition.






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   When an Intra-AS I-PMSI A-D route, advertised with a PTA having SR
   P2MP P-tunnel Type is withdrawn, a PE MUST remove the disposition
   state of the Tree-SID associated with P2MP tree.

   A PE MAY aggregate two or more Intra-AS I-PMSIs from different MVPNs
   onto the same SR P2MP P-tunnel.  When a remote PE withdraws an Intra-
   AS I-PMSI A-D route from a MVPN, and if this is the last MVPN sharing
   a SR P2MP P-tunnel, a PE must remove the originating PE as a Leaf
   from the P2MP tree, by invoking UpdateLeafSet API.

4.2.  Using S-PMSIs for binding customer flows to P2MP Segments

   RFC 6514 specifies procedures for binding (C-S,C-G) customer flows to
   P-tunnels using S-PMSI A-D routes.  Wildcards in Multicast VPN Auto-
   Discovery Routes [RFC6625] specifies additional procedures to binding
   aggregate customer flows to P-tunnels using "wildcard" S-PMSI A-D
   routes.  This section describes modification to these procedures for
   SR P2MP P-tunnels.

4.2.1.  Originating S-PMSI A-D routes

   RFC 6514 Section 12.1 [4] describes procedures for originating S-PMSI
   A-D routes.  For SR P2MP P-tunnels, these procedures remain unchanged
   except as described in the following paragraphs.

   When a PE originates S-PMSI A-D route with a PTA having SR P2MP
   P-tunnel Type, it MUST set the "Leaf Info Required bit" in the PTA.
   The PE MUST create a SR P2MP policy by invoking1 API of the PCE.
   When the PCEinstantiates the P2MP tree on the PE, the Tree-SID MUST
   be imposed for customer flows steered into the SR P2MP P-tunnel.

   The Leaf nodes of P2MP tree are discovered by Leaf A-D routes using
   procedures described in Section 4.4.2.  When a PE originates S-PMSI
   A-D route with a PTA having SR P2MP P-tunnel Type, it is possible the
   PE might have imported Leaf A-D routes whose route keys match the
   S-PMSI A-D route.  The PE MUST re-apply procedures of Section 4.4.2
   to these Leaf A-D routes.

   When a PE withdraws a S-PMSI A-D route, advetised with PTA having
   P2MP tree P-tunnle type, the Tree-SID imposition state MUST be
   removed.

   A PE MAY aggregate two or more S-PMSIs onto the same SR P2MP
   P-tunnel.  When a PE withdraws the last S-PMSI A-D route, advertised
   with a PTA identifying a specific SR P2MP P-tunnel , it SHOULD remove
   the SR P2MP policy by invoking DeletePolicy API of the PCE.





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4.2.2.  Receiving S-PMSI A-D routes

   RFC 6514 Section 12.3 [5] describes procedures for receiving S-PMSI
   A-D routes.  For SR P2MP P-tunnels, these procedures remain unchanged
   except as described in the following paragraphs.

   The procedure to join SR P2MP P-tunnel of S-PMSI A-D route by using a
   Leaf A-D route is described in Section 4.4.1.  If P2MP tree
   identified in PTA of S-PMSI A-D route is already instantiated by PCE,
   the PE MUST program Tree-SID for disposition.  If the P2MP tree is
   instantiated later, the Tree-SID MUST be programmed for disposition
   at that time.

   When a S-PMSI A-D route, whose SR P2MP P-tunnel is joined by a PE, is
   withdrawn, or when conditions (see RFC 6514 Section 12.3 [6])
   required to join that P-Tunnel are no longer satisfied, the PE MUST
   leave the P-Tunnel.  The PE MUST withdraw the Leaf A-D route it had
   originated and remove the Tree-SID disposition state.

4.3.  Inter-AS P-tunnels using P2MP Segments

   A segmented inter-AS P-tunnel consists of one or more intra-AS
   segments, one in each AS, connected by inter-AS segments between
   ASBRs of different ASes <https://tools.ietf.org/html/rfc6514#section-
   9.2>.  These segments are constructed by PEs/ASBRs originating or re-
   advertising Inter-AS I-PMSI A-D routes.  This section describes
   procedures for instantiating intra-AS segments using SR P2MP trees.

4.3.1.  Advertising Inter-AS I-PMSI routes into iBGP

   RFC 6514 Section 9.2.3.2 [7] specifies procedures for advertising an
   Inter-AS I-PMSI A-D route to construct an intra-AS segment.  The PTA
   of the route identifies the type and identifier of the P-tunnel
   instantiating the intra-AS segment.  The procedure for creating SR
   P2MP P-tunnel for intra-AS segment are same as specified in
   Section 4.2.1 except that instead of S-PMSI A-D routes, the
   procedures apply to Inter-AS I-PMSI A-D routes.

4.3.2.  Receiving Inter-AS I-PMSI A-D routes in iBGP

   RFC 6514 Section 9.2.3.2 [8] specifies procedures for processing an
   Inter-AS I-PMSI A-D route received via iBGP.  If the PTA of the
   Inter-AS I-PMSI A-D route has SR P2MP P-tunnel Type, the procedures
   are same as specified in Section 4.2.2 except that instead of S-PMSI
   A-D routes, the procedures apply to Inter-AS I-PMSI A-D routes.  If
   the receiving router is an ASBR, the Tree-SID is stitched to the
   inter-AS segments to ASBRs in other ASes.




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4.4.  Leaf A-D routes for P2MP Segment Leaf Discovery

   This section describes procedures for originating and processing Leaf
   A-D routes used for Leaf discovery of SR P2MP trees.

4.4.1.  Originating Leaf A-D routes

   The procedures for originating Leaf A-D route in response to
   receiving a S-PMSI or Inter-AS I-PMSI A-D route with PTA having SR
   P2MP P-tunnel Type are same as specified in RFC 6514
   Section 9.2.3.4.1 [9].

4.4.2.  Receiving Leaf A-D routes

   Procedures for processing a received Leaf A-D route are specified in
   RFC 6514 Section 9.2.3.5 [10].  These procedures remain unchanged for
   discovering Leaf nodes of P2MP trees except for considerations
   described in following paragraphs.  These procedures apply to Leaf
   A-D routes received in response to both S-PMSI and Inter-AS I-PMSI
   A-D routes, shortened to "A-D routes" in this section

   A Root PE/ASBR MAY use the same SR P2MP P-tunnel in PTA of two or
   more A-D routes.  For such aggregated P2MP trees, the PE/ASBR MAY
   receive multiple Leaf A-D routes from a Leaf PE.  The P2MP tree for
   which a Leaf A-D is received can be identified by examining the P2MP
   tunnel Identifier in the PTA of A-D route that matches "Route Key"
   field of the Leaf A-D route.  When the PE receives the first Leaf A-D
   route from a Leaf PE, identified by the Originating Router's IP
   address field, it MUST add that PE as Leaf of the P2MP tree by
   invoking the UpdateLeafSet API of the PCE.

   When a Leaf PE withdraws the last Leaf A-D route for a given SR P2MP
   P-tunnel, the Root PE MUST remove the Leaf PE from the P2MP tree by
   invoking UpdateLeafSet API of PCE.  Note that Root PE MAY remove the
   P2MP tree, via the DeletePolicyAPI, before the last Leaf A-D is
   withdrawn.  In this case, the Root PE MAY decide to not invoke the
   UpdateLeafSet API.

5.  Dampening of MVPN routes

   When P2MP trees are used as P-Tunnels for S-PMSI A-D routes, change
   in group membership of receivers connected to PEs has direct impact
   on the Leaf node set of a P2MP tree.  If group membership changes
   frequently for a large number of groups with a lot of receivers
   across sites connected to different PEs, it can have an impact on the
   interaction between PEs and the PCE.





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   Since Leaf A-D routes are used to discover Leaf PE of a P2MP tree, it
   is RECOMMENDED that PEs SHOULD damp Leaf A-D routes as described in
   Section 6.1 of RFC 7899 [RFC7899].  PEs MAY also implement procedures
   for damping other Auto-Discovery and BGP C-multicast routes as
   described in [RFC7899].

6.  SR P2MP Trees for EVPN

   BGP MPLS Ethernet VPN specified in RFC 7432 specifies Inclusive
   Multicast Ethernet Tag route to support Broadcast, Unknown Unicast
   and Multicast (BUM) traffic.  This IMET route is the equivalent of
   MVPN Intra-AS I-PMSI route and is advertised with a PMSI Tunnel
   Attribute (PTA) as specified in RFC 6514 to advertise the inclusive
   P-tunnels.

   [I-D.ietf-bess-evpn-bum-procedure-updates] updates BUM procedures to
   support selective P-tunnels and P-tunnel segmentation in EVPN.  That
   document specifies new route types that are advertised with PTA,
   including Selective PMSI (S-PMSI) Auto-Discovery route.

   These inclusive/selective P-tunnels can be realized by SR P2MP trees.
   As with other types of P2MP P-tunnels, the ESI label used for split
   horizon MUST be either upstream assigned by PE advertising the IMET
   or S-PMSI route, or assigned from a global context such as "Domain-
   wide Common Block" (DCB) as specified in
   [I-D.ietf-bess-mvpn-evpn-aggregation-label].

   [I-D.ietf-bess-evpn-irb-mcast] specifies procedures to support Inter-
   Subnet Multicast.  [I-D.ietf-bess-evpn-mvpn-seamless-interop]
   specifies how MVPN SAFI routes can be used to support Inter-Subnet
   Multicast.  The P-tunnels advertised in PTA of either EVPN and MVPN
   routes as specified in these documents respectively can be realized
   by SR P2MP trees.

   SRv6 P2MP trees can serve as an underlay multicast as described in
   RFC 8293 Section 3.4 [11].  A NVE encapsuates a tenant packet in an
   SRv6 header and deliver it over SRv6 P2MP trees to other NVEs.

   The same procedures specified for MVPN are used to collect the leaf
   information of corresponding SR P2MP tree (either based on IMET route
   or Leaf A-D routes in response to x-PMSI routes), to pass the tree
   information to the PCE controller, and to get back tree forwarding
   state used for customer multicast traffic forwarding.








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7.  IANA Considerations

   IANA is requested assign codepoint for "SR-MPLS P2MP Tree" in the
   "P-Multicast Service Interface Tunnel (PMSI Tunnel) Tunnel Types"
   registry <https://www.iana.org/assignments/bgp-parameters/bgp-
   parameters.xhtml#pmsi-tunnel-types> [RFC 7538] in the "Border Gateway
   Protocol (BGP) Parameters" registry.  A proposed value is 0x0C.

8.  Security Considerations

   The procedures in this document do not introduce any additional
   security considerations beyond those mentioned in [RFC6513] and
   [RFC6514].  For general security considerations applicable to P2MP
   trees, please refer to [I-D.ietf-pim-sr-p2mp-policy] .

9.  Acknowledgements

   The authors would like to acknowledge Luc Andre Burdett reviweing the
   document..

10.  Contributors

   Zafar Ali
   Cisco Systems, Inc.
   US

   Email: zali@cisco.com

   Ehsan Hemmati
   Cisco Systems, Inc.
   US

   Email: ehemmati@cisco.com

   Jayant Kotalwar
   Nokia
   Mountain View
   US

   Email: jayant.kotalwar@nokia.com

   Tanmoy Kundu
   Nokia
   Mountain View
   US

   Email: tanmoy.kundu@nokia.com




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   Clayton Hassen
   Bell Canada
   Vancouver
   CA

   Email: clayton.hassen@bell.ca

11.  References

11.1.  Normative References

   [I-D.ietf-pim-sr-p2mp-policy]
              Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z.
              Zhang, "Segment Routing Point-to-Multipoint Policy",
              draft-ietf-pim-sr-p2mp-policy-01 (work in progress),
              October 2020.

   [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>.

   [RFC6513]  Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
              BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
              2012, <https://www.rfc-editor.org/info/rfc6513>.

   [RFC6514]  Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
              Encodings and Procedures for Multicast in MPLS/BGP IP
              VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012,
              <https://www.rfc-editor.org/info/rfc6514>.

11.2.  Informative References

   [I-D.ietf-bess-evpn-bum-procedure-updates]
              Zhang, Z., Lin, W., Rabadan, J., Patel, K., and A.
              Sajassi, "Updates on EVPN BUM Procedures", draft-ietf-
              bess-evpn-bum-procedure-updates-08 (work in progress),
              November 2019.

   [I-D.ietf-bess-evpn-irb-mcast]
              Lin, W., Zhang, Z., Drake, J., Rosen, E., Rabadan, J., and
              A. Sajassi, "EVPN Optimized Inter-Subnet Multicast (OISM)
              Forwarding", draft-ietf-bess-evpn-irb-mcast-05 (work in
              progress), October 2020.







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   [I-D.ietf-bess-evpn-mvpn-seamless-interop]
              Sajassi, A., Thiruvenkatasamy, K., Thoria, S., Gupta, A.,
              and L. Jalil, "Seamless Multicast Interoperability between
              EVPN and MVPN PEs", draft-ietf-bess-evpn-mvpn-seamless-
              interop-01 (work in progress), July 2020.

   [I-D.ietf-bess-mvpn-evpn-aggregation-label]
              Zhang, Z., Rosen, E., Lin, W., Li, Z., and I. Wijnands,
              "MVPN/EVPN Tunnel Aggregation with Common Labels", draft-
              ietf-bess-mvpn-evpn-aggregation-label-04 (work in
              progress), November 2020.

   [I-D.ietf-spring-sr-replication-segment]
              Voyer, D., Filsfils, C., Parekh, R., Bidgoli, H., and Z.
              Zhang, "SR Replication Segment for Multi-point Service
              Delivery", draft-ietf-spring-sr-replication-segment-03
              (work in progress), October 2020.

   [RFC6625]  Rosen, E., Ed., Rekhter, Y., Ed., Hendrickx, W., and R.
              Qiu, "Wildcards in Multicast VPN Auto-Discovery Routes",
              RFC 6625, DOI 10.17487/RFC6625, May 2012,
              <https://www.rfc-editor.org/info/rfc6625>.

   [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>.

   [RFC7899]  Morin, T., Ed., Litkowski, S., Patel, K., Zhang, Z.,
              Kebler, R., and J. Haas, "Multicast VPN State Damping",
              RFC 7899, DOI 10.17487/RFC7899, June 2016,
              <https://www.rfc-editor.org/info/rfc7899>.

   [RFC8293]  Ghanwani, A., Dunbar, L., McBride, M., Bannai, V., and R.
              Krishnan, "A Framework for Multicast in Network
              Virtualization over Layer 3", RFC 8293,
              DOI 10.17487/RFC8293, January 2018,
              <https://www.rfc-editor.org/info/rfc8293>.

   [RFC8660]  Bashandy, A., Ed., Filsfils, C., Ed., Previdi, S.,
              Decraene, B., Litkowski, S., and R. Shakir, "Segment
              Routing with the MPLS Data Plane", RFC 8660,
              DOI 10.17487/RFC8660, December 2019,
              <https://www.rfc-editor.org/info/rfc8660>.







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11.3.  URIs

   [1] https://tools.ietf.org/html/draft-ietf-pim-sr-p2mp-policy-
       00#section-4.1.1

   [2] https://tools.ietf.org/html/rfc6514#section-9.1.1

   [3] https://tools.ietf.org/html/rfc6514#section-9.1.2

   [4] https://tools.ietf.org/html/rfc6514#section-12.1

   [5] https://tools.ietf.org/html/rfc6514#section-12.3

   [6] https://tools.ietf.org/html/rfc6514#section-12.3

   [7] https://tools.ietf.org/html/rfc6514#section-9.2.3.2

   [8] https://tools.ietf.org/html/rfc6514#section-9.2.3.2

   [9] https://tools.ietf.org/html/rfc6514#section-9.2.3.4.1

   [10] https://tools.ietf.org/html/rfc6514#section-9.2.3.5

   [11] https://tools.ietf.org/html/rfc8293#section-3.4

Authors' Addresses

   Rishabh Parekh
   Cisco Systems, Inc.
   170 W. Tasman Drive
   San Jose, CA  95134
   USA

   Email: riparekh@cisco.com


   Clarence Filsfils
   Cisco Systems, Inc.
   Brussels
   BE

   Email: cfilsfil@cisco.com









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   Arvind Venkateswaran
   Cisco Systems, Inc.
   170 W. Tasman Drive
   San Jose, CA  95134
   USA

   Email: arvvenka@cisco.com


   Hooman Bidgoli
   Nokia
   Ottawa
   CA

   Email: hooman.bidgoli@nokia.com


   Daniel Voyer
   Bell Canada
   Montreal
   CA

   Email: daniel.voyer@bell.ca


   Zhaohui Zhang
   Juniper Networks

   Email: zzhang@juniper.net






















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