PCE Working Group                                                A. Wang
Internet-Draft                                             China Telecom
Intended status: Standards Track                             B. Khasanov
Expires: March 18, April 23, 2021                                          S. Fang
                                                                  R. Tan
                                             Huawei Technologies,Co.,Ltd
                                                                  C. Zhu
                                                         ZTE Corporation
                                                      September 14,
                                                        October 20, 2020

                  PCEP Extension for Native IP Network
               draft-ietf-pce-pcep-extension-native-ip-08
               draft-ietf-pce-pcep-extension-native-ip-09

Abstract

   This document defines the Path Computation Element Communication
   Protocol (PCEP) extension for Central Control Dynamic Routing (CCDR)
   based application in Native IP network.  The scenario and framework
   of CCDR in native IP is described in [RFC8735] and
   [I-D.ietf-teas-pce-native-ip].  This draft describes the key
   information that is transferred between Path Computation Element
   (PCE) and Path Computation Clients (PCC) to accomplish the End to End
   (E2E) traffic assurance in Native IP network under central control
   mode.

Status of This Memo

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   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on March 18, April 23, 2021.

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   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  STATEFUL-PCE-CAPABILITY TLV  Capability Advertisemnt . . . . . . . . . . . . . . . . . . .   3
     4.1.  Open message  . . . . . . . . . . . . . . . . . . . . . .   3
   5.  PCE-Initiated  PCEP messages . . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  The PCInitiate message  . . . . . . . . . . . . . . . . .   4
     5.2.  The PCRpt message . . . . . . . . . . . . . . . . . . . .   5
   6.  PCECC Native IP TE Procedures . . . . . . . . . . . .   4
   6.  New Objects Extension . . . .   6
     6.1.  BGP Session Establishment Procedures  . . . . . . . . . .   6
     6.2.  Explicit Route Establish Procedures . . . . . . . . . . .   4   9
     6.3.  BGP Prefix Advertisement Procedures . . . . . . . . . . .  12
   7.  New PCEP Objects Formats .  . . . . . . . . . . . . . . . . . . . . . .   4  13
     7.1.  CCI Object  . . . . . . . . . . . . . . . . . . . . . . .  13
     7.2.  BGP Peer Info Object  . . . . . . . . . . . . . . . . . .   5
     7.2.  14
     7.3.  Explicit Peer Route Object  . . . . . . . . . . . . . . .   9
     7.3.  17
     7.4.  Peer Prefix Association Object  . . . . . . . . . . . . .  13  18
   8.  New Error-Types and Error-Values Defined  . . . . . . . . . .  16  19
   9.  Management Consideration  . . . . . . . . . . . . . . . . . .  17  20
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  18  21
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18  21
     11.1.  PCEP Object Types  . . . . . . . . . . . . . . . . . . .  18  21
   12. Acknowledgement Contributor . . . . . . . . . . . . . . . . . . . . . . .  18 . .  21
   13. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  21
   14. Normative References  . . . . . . . . . . . . . . . . . . . .  18  22
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  19  23

1.  Introduction

   Traditionally,

   Generally, Multiprotocol Label Switching Traffic Engineering
   (MPLS-TE) (MPLS-
   TE) requires the corresponding network devices support Multiprotocol
   Label Switching (MPLS) or Resource ReSerVation Protocol (RSVP)/Label
   Distribution Protocol (LDP) technologies to assure the End-to-End
   (E2E) traffic performance.  But in native IP network, there will be
   no such signaling protocol to synchronize the action among different
   network devices.  It is necessary to use the central control mode
   that described in [RFC8283] to correlate the forwarding behavior
   among different network devices.  Draft [I-D.ietf-teas-pce-native-ip]
   describes the architecture and solution philosophy for the E2E
   traffic assurance in Native IP network via
   Dual/Multi Multi Border Gateway
   Protocol (BGP) solution.  This draft describes the corresponding Path
   Computation Element Communication Protocol (PCEP) extensions to
   transfer the key information about BGP peer
   address list, info, peer prefix
   association and the explicit peer route on on-path routers.

2.  Conventions used in this document

   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 RFC 2119 [RFC2119]. BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  Terminology

   This document uses the following terms defined in [RFC5440]: PCE,
   PCEP

   The following terms are defined in this document:

   o  CCDR: Central Control Dynamic Routing

   o  E2E: End to End

   o  BPI: BGP Peer Info

   o  EPR: Explicit Peer Route

   o  PPA: Peer Prefix Association

   o  QoS: Quality of Service

4.  STATEFUL-PCE-CAPABILITY TLV

   The format of STATEFUL-PCE-CAPABILITY is defined in [RFC8231] and
   included here for easy reference with  Capability Advertisemnt

4.1.  Open message

   During the addition PCEP Initialization Phase, PCEP Speakers (PCE or PCC)
   advertise their support of the Native IP extensions.

   This document defines a new N flag.
   The right bits of N flag have been defined by other RFC documents.

     0                   1                   2                   3
     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    | Path Setup Type            |            Length=4           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |              Flags                        |N|*|*|*|*|*|*|I|S|U|
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+-+-+-+-+-++-+-+-+-+-+
              Figure 1: STATEFUL-PCE-CAPABILITY TLV Format

   A new flag is defined to indicate the sender's support (PST) [RFC8408] for traffic
   engineering in
   Native-IP, as follows:

   o  PST = TBD1: Path is a Native IP network.  The newly defined path as per
      [I-D.ietf-teas-pce-native-ip].

   A PCEP Objects and speaker MUST indicate its proceeding procedures, as stated support of the function described in Section 6 MUST be supported
   this document by PCC or PCE when sending a PATH-SETUP-TYPE-CAPABILITY TLV in the OPEN
   object with this new PST included in the PST list.

   [I-D.ietf-pce-pcep-extension-for-pce-controller] defined the PCECC-
   CAPABILITY sub-TLV to exchange information about their PCECC
   capability.  A new flag is set.

   N( NATIVE-IP-TE-CAPABILITY-----1 bit): defined in PCECC-CAPABILITY sub-TLV for
   Native IP.

   N (NATIVE-IP-TE-CAPABILITY - 1 bit - TBD2): If set to 1 by a PCC/PCE, the
   N flag indicate PCEP
   speaker, it indicates that the PCC/PCE can support the traffic engineering PCEP speaker is capable for TE in
   Native IP network. network as specified in this document.  The NATIVE-IP-TE-CAPABILITY flag MUST be
   set by both the PCC and PCE in order to enable PCE-initiated Native IP
   traffic engineering. support this extension.

5.  PCE-Initiated Native IP TE Procedures

   PCE-Initated  PCEP messages

   PCECC Native IP TE solution utilizing the existing PCE LSP Initate
   Request message(PCInitiate)[RFC8281], and PCE Report message(PCRpt) [RFC8281]and PCE Update message(PCUpd)[RFC8281]
   [RFC8281] to accomplish the multi BGP sessions establishment, end to
   end TE path deployment, and route prefixes advertisement among
   different BGP sessions.

   There  A new PST for Native-IP is no label switch path within the Native IP environment, but
   there exist end to end forwarding path that assigned used to indicate
   the priority
   traffic.  Such path can be identified by the PLSP-ID that defined in
   Label Switched Path(LSP) object [RFC8231]_. _The PLSP-ID is assigned
   by each PCC, setup based on the Symbolic Path Name TLV in the LSP object
   that from PCInitiate message.  The Symbolic Path Name TLV can be used
   to identify the end to end TE path in Native IP environment. networks.

   The
   association of Symbolic Path Name and each PLSP-ID extended PCInitiate message described in every PCC
   assures the TE policies are assigned end
   [I-D.ietf-pce-pcep-extension-for-pce-controller] is used to end in download
   or cleanup central controller's instructions (CCIs).
   [I-D.ietf-pce-pcep-extension-for-pce-controller] specify an object
   called CCI for the network.

6.  New Objects Extension

   Three encoding of central controller's instructions.
   This document specify a new objects CCI object-type for Native IP.  The PCEP
   messages are defined extended in this draft:

   o  BPI Object: BGP document to handle the PCECC operations
   for Native IP.  Three new PCEP Objects (BGP Peer Info (BPI) Object, used to indicate the PCC which
      BGP peer it should be peered with dynamically.

   o  EPR Object:
   Explicit Peer Route object, used to indicate the PCC
      which route should be taken into to arrive to the peer.

   o  PPA Object: (EPR) Object and Peer Prefix Association Object, used to indicate the
      PCC which prefixes should be advertised via the corresponding BGP
      peer.

7.  Objects Formats

   Each extension (PPA)
   Object) are defined in this document.  Refer toSection 7 for detail
   object takes the similar format, that definitions.

5.1.  The PCInitiate message

   The PCInitiate Message defined in [RFC8281] and extended in
   [I-D.ietf-pce-pcep-extension-for-pce-controller] is further extended
   to say, it
   began with support Native-IP CCI.

   The format of the common object header extended PCInitiate message is as follows:

        <PCInitiate Message> ::= <Common Header>
                                 <PCE-initiated-lsp-list>
     Where:
        <Common Header> is defined in [RFC5440]

        <PCE-initiated-lsp-list> ::= <PCE-initiated-lsp-request>
                                     [<PCE-initiated-lsp-list>]

        <PCE-initiated-lsp-request> ::=
                             (<PCE-initiated-lsp-instantiation>|
                              <PCE-initiated-lsp-deletion>|
                              <PCE-initiated-lsp-central-control>)

        <PCE-initiated-lsp-central-control> ::= <SRP>
                                                (<LSP>
                                                <cci-list>)|
                                                ((<BPI>|<EPR>|<PPA>)
                                                <CCI>)

        <cci-list> ::=  <CCI>
                        [<cci-list>]

     Where:
         <cci-list> is as the
   following:

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |  Object-Class |   OT  |Res|P|I|        Object Length(bytes)   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       (Object body)                           |
      //                                                             //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                    Figure 2: PCEP Object Format

   Different object-class, object type per
         [I-D.ietf-pce-pcep-extension-for-pce-controller].
         <PCE-initiated-lsp-instantiation> and the corresponding
         <PCE-initiated-lsp-deletion> are as per
         [RFC8281].

        The LSP and SRP object body is defined separately in [RFC8231].

   When PCInitiate message is used create Native IP instructions, the following sections.

7.1.  BGP Peer Info Object
   SRP and CCI objects MUST be present.  The BGP Peer Info error handling for missing
   SRP or CCI object is used to specify the information about the
   peer that the PCC should establish the BGP relationship with.  This as per
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Further either one
   of BPI, EPR, or PPA object should only MUST be included and sent to present.  If none of them are
   present, the head receiving PCC MUST send a PCErr message with Error-
   type=6 (Mandatory Object missing) and end router of Error-value=TBD (Native IP
   object missing).

   To cleanup the E2E path SRP object must set the R (remove) bit.

5.2.  The PCRpt message

   The PCRpt message is used to acknowledge the Native-IP instructions
   received from the central controller (PCE).

   The format of the PCRpt message is as follows:

         <PCRpt Message> ::= <Common Header>
                             <state-report-list>
      Where:

         <state-report-list> ::= <state-report>[<state-report-list>]

         <state-report> ::= (<lsp-state-report>|
                             <central-control-report>)

         <lsp-state-report> ::= [<SRP>]
                                <LSP>
                                <path>

         <central-control-report> ::= [<SRP>]
                                      (<LSP>
                                      <cci-list>)|
                                      ((<BPI>|<EPR>|<PPA>)
                                      <CCI>)

       Where:
         <path> is as per [RFC8231] and the LSP and SRP object are
         also defined in case there [RFC8231].

   The error handling for missing CCI object is no Route Reflection (RR) involved. as per
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Further either one
   of BPI, EPR, or PPA object MUST be present.  If none of them are
   present, the RR is used receiving PCE MUST send a PCErr message with Error-
   type=6 (Mandatory Object missing) and Error-value=TBD ( Native IP
   object missing).

6.  PCECC Native IP TE Procedures

   The detail procedures for the TE in native IP environment are
   described in the following sections.

6.1.  BGP Session Establishment Procedures

   The procedures for establishing the BGP session between two peers is
   shown below, using the head PCInitiate and end routers, then such
   information PCRpt message pair.

   The PCInitiate message should be sent to head router, RR PCC which acts as BGP
   routers and end router
   respectively.

   By default, there MUST be no prefix route reflector.  In the example in Figure 1, it should
   be distributed via such sent to R1(M1), R3(M2 & M3) and R7(M4), when R3 acts as RR.

   When PCC receives the BPI and CCI object (with the R bit set to 0 in
   SRP object) in PCInitiate message, the PCC should try to establish
   the BGP session that established by this object.

   By default, with the indicated Peer AS and Local/Peer IP address SHOULD be dedicated to address.

   When PCC creates successfully the
   usage of native IP TE solution, and SHOULD not be used by other BGP
   sessions session that established by manual or non PCE initiated
   configuration.

   BGP Peer Info Object-Class is TBD

   BGP Peer Info Object-Type is 1 for IPv4 and 2 for IPv6

   The format of indicated by
   the BGP Peer Info object body for IPv4(Object-Type=1)
   is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 associated information, it should report the result via the PCRpt
   messages, with BPI object included, and the corresponding SRP and CCI
   object.

   When PCC receives this message with the R bit set to 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | in SRP object
   in PCInitiate message, the PCC should clear the BGP session that
   indicated by the BPI object.

   When PCC clears successfully the specified BGP session, it should
   report the result via the PCRpt message, with the BPI object
   included, and the corresponding SRP and CCI object.

 M2   PCInitiate Message:                           M3   PCInitiate Message:
      CC-ID=X3(Symbolic Path Name=Class A)               CC-ID=X3(Symbolic Path Name=Class A)
      BPI Object(Local IP=R3_A, Peer AS Number IP=R1_A)            BPI Object(Local IP=R3_A, Peer IP=R7_A)

M2-R PCRpt Message:                                 M3-R PCRpt Message:
      CC-ID=X3                                           CC-ID=X3
      BPI Object(Local IP=R3_A, Peer IP=R1_A)            BPI Object(Local IP=R3_A, Peer IP=R7_A)
                     ^                                                       ^
                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                                       |   ETTL
                     +------------------------------------^------------------+
                                                          |              Reserved
                                                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                                          |                    Local IP Address
                                                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+    +------------------+
 M1    PCInitiate Message:                          +----------+       PCE        +-----------+
       CC-ID=X1(Symbolic Path Name=Class A)         |     |    +--------^---------+           |
       BPI Object(Local IP=R1_A, Peer IP Address IP=R3_A)      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+     |                  Additional TLVs             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        Figure 3: BGP Peer Info Object Body Format for IPv4

   The format of the BGP                     |
                                                    |     |             |                     |
                                             <------+     +-------------+                     +---+
 M1-R PCRpt Message:                                |                   |                     |   |
      CC-ID=X1                                      |                  +v-+                   |   |
      BPI Object(Local IP=R1_A, Peer Info object body for IPv6(Object-Type=2)
   is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 IP=R3_A        +------------------+R3+-------------------+   |                                                                                  )
                                                    |                  +--+                   |   |
                                                    |                                         |   |
                                                   +v-+          +--+          +--+         +-v+  |
                                                   |R1+----------+R5+----------+R6+---------+R7|  |
                                                   ++-+          +--+          +--+         +-++  |
M4  PCInitiate Message:                             |                                         |   |
    CC-ID=X7(Symbolic Path Name=Class A)            |                                         |   |
    BPI Object(Local IP=R7_A,Peer IP=R3_A)          |            +--+          +--+           |   |
                                                    +------------+R2+----------+R4+-----------+   |
                                                                                                  |
M4-R PCRpt Message:                                                                               |
      CC-ID=X7                               <----------------------------------------------------+
      BPI Object(Local IP=R3_A, Peer IP=R1_A)

                         Figure 1: BGP Session Establishment Procedures(R3 act as RR)

   If the PCC cannot establish the BGP session that required by this
   object, it should report the error values with the newly defined
   error type(Error-type=TBD) and error value(Error-Value=01 or 02),
   which is indicated in Section 8 9

6.2.  Explicit Route Establish Procedures

   The detail procedures for the explicit route establishment procedures
   is shown below, using PCInitiate and PCRpt message pair.

   The PCInitiate message should be sent to the on-path routers
   respectively.  In the example, for explicit route from R1 to R7, the
   PCInitiate message should be sent to R1(M1), R2(M2) and R4(M3), as
   shown in Figure 2.  For explicit route from R7 to R1, the PCInitiate
   message should be sent to R7(M1), R4(M2) and R2(M3), as shown in
   Figure 3..

   When PCC receives the EPR and the CCI object (with the R bit set to 0
   in SRP object) in PCInitiate message, the PCC should install the
   explicit route to the the peer.

   When PCC install successfully the explicit route to the peer, it
   should report the result via the PCRpt messages, with EPR object
   included, and the corresponding SRP and CCI object.

   When PCC receives the EPR and the CCI object with the R bit set to 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   in SRP object in PCInitiate message, the PCC should clear the
   explicit route to the peer that indicated by the EPR object.

   When PCC clear successfully the explicit route that indicated by this
   object, it should report the result via the PCRpt message, with the
   EPR object included, and the corresponding SRP and CCI object.

                                                              +------------------+
M1    PCInitiate Message:                          +----------+       PCE        +-----------+
      CC-ID=X1(Symbolic Path Name=Class A)         |          +----^---^---^-----+           |
      EPR Object(Peer Address=R7_A                 |               |   |   |                 |
                 Next Hop=R2_A)                    |               |   |   |                 |
                                                   |               |   |   |                      Peer AS Number                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
M1-R PCRpt Message:                <---------------+               |   ETTL   |              Reserved   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                 |
     CC-ID=X1                                      |
   +                                                               +               |               Local IP Address (16 bytes)  +v-+ |
   +                                                               +                 |
     EPR Object(Peer Address=R7_A                  +------------+ +---+R3+-------------------+                                                                                       )
                Next Hop=R2_A)                     |
   +                                                               +               |  +--+ |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                 |
                                                   |
   +                                                               +               |               Peer IP Address (16 bytes)       |
   +                                                               +                 |
                                                  +v-+      +--+   |
   +                                                               +       |       +--+    +-v+
                                                  |R1+------+R5++ +----------------+R6+----+R7|
                                                  ++-+      +--+   |       |       +--+    +-++
                                                   |               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+       |                  Additional TLVs                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 4: BGP Peer Info Object Body Format for IPv6

   Peer AS Number: 4 Bytes, to indicate the AS number of Remote Peer.

   ETTL: 1 Bytes, to indicate the multi hop count for EBGP session.  It
   should be 0 and ignored when Local AS and Peer AS is same.

   Reserved: Bits reserved for future use.

   Local IP Address(4/16 Bytes): IP address of the local router, used to
   peer with other end router.  When Object-Type is 1, length is 4
   bytes; when Object-Type is 2, length is 16 bytes.

   Peer IP Address(4/16 Bytes): IP address of the peer router, used to
   peer with the local router.  When Object-Type is 1, length is 4
   bytes; when Object-Type is 2, length is 16 bytes;

   Additional TLVs: TLVs that associated with this object, can be used
   to convey other necessary information for dynamic BGP session
   establishment.  Its definition is out of the current document.

   The detail procedures for the usage of this object is shown
   below(PCInitiate and PCRpt message pair, other message pairs are
   similar)

   The PCInitiate message should be sent to R1(M1), R3(M2 & M3) and
   R7(M4) when R3 acts as RR.
M2  PCInitiate Message:                           M3   PCInitiate Message:
      PLSP-ID=X3(Symbolic Message                             |           +---+       +---+             |
    CC-ID=X2(Symbolic Path Name=Class A)           |          +v-+ |       |  +v-+           |
    EPR Object(Peer Address=R7_A                   +----------+R2+-+ +--------+R4+-----------+
               Next Hop=R4_A)                                      |       |
                                                                   |       |
M2-R PCRpt Message                                                 |       |
     CC-ID=X2(Symbolic Path Name=Class A)             PLSP-ID=X3(Symbolic   <----------------------+       |
     EPR Object(Peer Address=R7_A                                          |
                Next Hop=R4_A)                                             |
                                                                           v
                                                    M3   PCInitiate Message
                                                         CC-ID=X4(Symbolic Path Name=Class A)
      BPI Object(Local IP=R3_A, Peer IP=R1_A)            BPI Object(Local IP=R3_A, Peer IP=R7_A)

M2-R PCRpt Message:
                                                         EPR Object(Peer Address=R7_A
                                                                    Next Hop=R7_A)

                                                    M3-R PCRpt Message:
      PLSP-ID=X3                                         PLSP-ID=X3
      BPI Object(Local IP=R3_A, Peer IP=R1_A)            BPI Object(Local IP=R3_A, Peer IP=R7_A)
                     ^                                                       ^
                     |                                                       |
                     +------------------------------------^------------------+
                                                          |
                                                          | Message
                                                         CC-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R7_A
                                                                    Next Hop=R7_A)

                      Figure 2: Explicit Route Establish Procedures(From R1 to R7)

              -------------------------------------------------------------------------+
              |                                                                        |
              v                                               +------------------+     |
M1    PCInitiate Message:                          +----------+       PCE        +-----------+
       PLSP-ID=X1(Symbolic        +-----+-----+
      CC-ID=X7(Symbolic Path Name=Class A)         |          +----^---^---^-----+           |
      EPR Object(Peer Address=R1_A                 |               |   |   |                 |
                 Next Hop=R4_A)                    |    +--------^---------+               |
       BPI Object(Local IP=R1_A, Peer IP=R3_A)   |   |                 |
                                                   |               |   |   |                 |
                                             <------+     +-------------+                     +---+
M1-R PCRpt Message:                                |               |   |   |
      PLSP-ID=X1                 |                  +v-+
     CC-ID=X7                                      |               |
      BPI Object(Local IP=R1_A, Peer IP=R3_A        +------------------+R3+-------------------+  +v-+ |                 |
     EPR Object(Peer Address=R1_A                  +------------+ +---+R3+-------------------+                                                                                       )
                Next Hop=R4_A)                     |               |  +--+ |                 |
                                                   |               |       |                 |
                                                  +v-+      +--+          +--+         +-v+   |
                                                   |R1+----------+R5+----------+R6+---------+R7|       |       +--+    +-v+
                                                  |R1+------+R5++ +----------------+R6+----+R7|
                                                  ++-+      +--+   |       |       +--+    +-++
                                                   |
M4  PCInitiate Message:               |       |                 |
    PLSP-ID=X7(Symbolic
M3  PCInitiate Message                             |           +---+       +---+             |
    CC-ID=X2(Symbolic Path Name=Class A)           |          +v-+ |       |
    BPI Object(Local IP=R7_A,Peer IP=R3_A)  +v-+           |            +--+          +--+
    EPR Object(Peer Address=R1_A                   +----------+R2+-+ +--------+R4+-----------+
               Next Hop=R1_A)                                      |       |
                                                    +------------+R2+----------+R4+-----------+
                                                                   |       |
M4-R
M3-R PCRpt Message: Message                                                 |
      PLSP-ID=X7                             <----------------------------------------------------+
      BPI Object(Local IP=R3_A, Peer IP=R1_A)       |
     CC-ID=X2(Symbolic Path Name=Class A)   <----------------------+       |
     EPR Object(Peer Address=R1_A                                          |
                Next Hop=R1_A)                                             |
                                                                           v
                                                    M2   PCInitiate Message
                                                         CC-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R1_A
                                                                    Next Hop=R2_A)

                                                    M2-R PCRpt Message
                                                         CC-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R1_A
                                                                    Next Hop=R2_A)

                     Figure 5: BGP Peer Establishment Procedures(R3 act 3: Explicit Route Establish Procedures(From R7 to R1)

   Upon the error occurs, the PCC SHOULD send the corresponding
   error(Error-type=TBD, Error-value=03) information that defined in
   Section 8.  When the peer info that associated with the Symbolic Path
   Name is not the same as RR)

   When PCC receives this object with the R bit set to 0 peer info that indicated in SRP EPR object in PCInitiate message, the PCC
   PCC, an error (Error-type=TBD, Error-value=04) should try to establish be reported via
   the PCRpt message.

6.3.  BGP
   session with the indicated Peer AS Prefix Advertisement Procedures

   The detail procedures for BGP prefix advertisement is shown below,
   using PCInitiate and Local/Peer IP address.

   When PCRpt message pair.

   The PCInitiate message should be sent to PCC creates successfully the BGP session that is indicated by acts as BGP peer
   router only.  In the associated information, example, it should report the result via the PCRpt
   messages, with this object included, and the corresponding SRP be sent to R1(M1) and
   LSP object. R7(M2)
   respectively.

   When PCC receives this the PPA and the CCI object with (with the R bit set to 1 0
   in SRP object object) in PCInitiate message, the PCC should clear send the BGP session that
   prefixes indicated by Local/Peer IP address.

   When PCC clears successfully the specified BGP session, it should
   report the result via the PCRpt message, with this object included,
   and the corresponding SRP and LSP object.

   When PCC receives in this object with the LSP object in PCE Update
   message, the PCC should update to the appointed BGP session that identified by the
   PLSP-ID with the updated information contained in this object. peer.

   When PCC updates sends successfully the BGP session that is indicated by prefixes to the PLSP-ID, appointed BGP peer,
   it should report the result via the PCRpt message, messages, with
   this PPA object
   included, and the corresponding SRP and LSP CCI object.

   Upon

   When PCC can't build the BGP session that required by this object, it
   should report the error values with receives the newly defined error type PPA and
   error value, which is indicated in Section 8

7.2.  Explicit Peer Route Object

   The Explicit Peer Route object is defined to specify the explicit
   peer route to CCI object with the corresponding peer address on each device that is
   on R bit set to 1
   in SRP object in PCInitiate message, the E2E assurance path.  This Object PCC should be sent withdraw the
   prefixes advertisement to all the
   devices peer that locates on indicated by this object.

   When PCC withdraws successfully the E2E assurance path prefixes that calculated by
   PCE.

   The path established indicated by this object should have higher priority than
   other path calculated by dynamic IGP protocol, but
   object, it should report the result via the PCRpt message, with the
   PPA object included, and the corresponding SRP and CCI object.

   The IPv4 prefix MUST only be lower
   priority that advertised via the static route configured by manual or NETCONF
   channel.

   Explicit Peer Route Object-Class is TBD.

   Explicit Peer Route Object-Type is 1 for IPv4 BGP session and 2 for
   the IPv6

   The format of Explicit Peer Route object body for IPv4(Object-Type=1) prefix MUST only be advertised via the IPv6 BGP session.  If
   mismatch occur, an error(Error-type=TBD, Error-value=05) should be
   reported.

   When the peer info that associated with the Symbolic Path Name is not
   the same as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ the peer info that indicated in PPA object in PCC, an
   error (Error-type=TBD, Error-value=06) should be reported via the
   PCRpt message.

                                                M2  PCInitiate Message:
                                                    CC-ID=X7(Symbolic Path Name=Class A)
                                                    PPA Object(Peer IP=R1_A, Prefix=7_A)

                                                                                           <-----+
                                                M2-R  PCRpt Message:                             |
                                                      CC-ID=X7                                   |
                                                      PPA Object(Peer IP=R1_A, Prefix=7_A)       |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                              +------------------+               |
M1   PCInitiate Message:                           +----------+       PCE        +-----------+   |
     CC-ID=X1(Symbolic Path Name=Class A)          |          +------------------+           |   |
     PPA Object(Peer IP=R7_A, Prefix=1_A)          |       Route Priority                                         |          Resv.   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                                   |                IPv4 Peer Address                                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   |           Next Hop Address to the IPv4 Peer Address
                                        <----------+                                         +---+
M1-R PCRpt Message:                                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                                         |
     CC-ID=X1                                      |                  +--+                   |
     PPA Object(Peer IP=R7_A,Prefix=1_A)           +------------------+R3+-------------------+                                                                                        )
                                                   |                  +--+                   |
                                                   |                                         |
                                                  +v-+          +--+          +--+         +-v+
                                                  |R1+----------+R5+----------+R6+---------+R7|
                                                  ++-+          +--+          +--+         +-++
                                                   |                                         |
                                                   |                                         |
                                                   |            +--+          +--+           |
                                                   +------------+R2+----------+R4+-----------+

                                       Figure 6: Explicit Peer Route 4: BGP Prefix Advertisement Procedures

7.  New PCEP Objects

   One new CCI Object and three new PCEP objects are defined in this
   draft.  All new PCEP objects are as per [RFC5440]

7.1.  CCI Object Body Format for IPv4

   The format of Explicit Peer Route object body Central Control Instructions (CCI) Object is used by the PCE to
   specify the forwarding instructions is defined in
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  This document
   defines another object-type for IPv6(Object-Type=2) Native-IP.

   CCI Object-Type is TBD for Native-IP as follows: below
    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Route Priority        |           Resv.                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |                      IPv6 Peer Address                        |
   +                                                               +
   |                                                               |
   +                                                               +
   |                            CC-ID                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Reserved             |
   +                                                               +
   |          Next Hop Address to the IPv6 Peer Address             Flags             |
   +                                                               +
   +---------------------------------------------------------------+
   |                                                               |
   +                                                               +
   //                        Optional TLV                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 7: Explicit Peer Route 5: CCI Object Body Format for IPv6

   Route Priority: 2 Bytes, Native IP

                                 Figure 1

   The priority of this explicit route. field CC-ID is as described in
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Following fields
   are defined for CCI Object-Type TBD

   Reserved:  is set to zero while sending, ignored on receipt.

   Flags:  is used to carry any additional information pertaining to the
      CCI.  Currently no flag bits are defined.

   The
   higher priority should Symbolic Path Name TLV [RFC8231] MUST be preferred by included in the device.

   Resv.: Bit reserved for future use.

   Peer Address: To indicate CCI
   Object-Type TBD to identify the peer address.

   Next Hop Address end to end TE path in Native IP
   environment and MUST be unique.

7.2.  BGP Peer Info Object

   The BGP Peer Info object is used to specify the Peer: To indicate information about the next hop address to
   peer that the
   corresponding peer.

   The detail procedures for PCC should establish the usage of this BGP relationship with.  This
   object is shown
   below(PCInitiate should only be included and PCRpt message pair, other message pairs are
   similar)

   For explicit route from R1 sent to R7, the PCIniitate message head and end router of
   the E2E path in case there is no Route Reflection (RR) involved.  If
   the RR is used between the head and end routers, then such
   information should be sent to R1(M1), R2(M2) head router, RR and R4(M3).

                                                              +------------------+
M1    PCInitiate Message:                          +----------+       PCE        +-----------+
      PLSP-ID=X1(Symbolic Path Name=Class A)       |          +----^---^---^-----+           |
      EPR Object(Peer Address=R7_A                 |               |   |   |                 |
                 Next Hop=R2_A)                    |               |   |   |                 |
                                                   |               |   |   |                 |
M1-R PCRpt Message:                <---------------+               |   |   |                 |
     PLSP-ID=X1                                    |               |  +v-+ |                 |
     EPR Object(Peer Address=R7_A                  +------------+ +---+R3+-------------------+                                                                                       )
                Next Hop=R2_A)                     |               |  +--+ |                 |
                                                   |               |       |                 |
                                                  +v-+      +--+   |       |       +--+    +-v+
                                                  |R1+------+R5++ +----------------+R6+----+R7|
                                                  ++-+      +--+   |       |       +--+    +-++
                                                   |               |       |                 |
M2  PCInitiate Message                             |           +---+       +---+             |
    PLSP-ID=X2(Symbolic Path Name=Class A)         |          +v-+ |       |  +v-+           |
    EPR Object(Peer Address=R7_A                   +----------+R2+-+ +--------+R4+-----------+
               Next Hop=R4_A)                                      |       |
                                                                   |       |
M2-R PCRpt Message                                                 |       |
     PLSP-ID=X2(Symbolic Path Name=Class A) <----------------------+       |
     EPR Object(Peer Address=R7_A                                          |
                Next Hop=R4_A)                                             |
                                                                           v
                                                    M3   PCInitiate Message
                                                         PLSP-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R7_A
                                                                    Next Hop=R7_A)

                                                    M3-R PCRpt Message
                                                         PLSP-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R7_A
                                                                    Next Hop=R7_A)

                            Figure 8: Explicit Route Establish Procedures(From R1 to R7)

   For explicit route from R7 to R1, end router
   respectively.

   By default, there MUST be no prefix be distributed via such BGP
   session that established by this object.

   By default, the PCIniitate message should Local/Peer IP address SHOULD be
   sent dedicated to R7(M1), R4(M2) the
   usage of native IP TE solution, and R2(M3).

              -------------------------------------------------------------------------+
              |                                                                        |
              v                                               +------------------+     |
M1    PCInitiate Message:                          +----------+ SHOULD NOT be used by other BGP
   sessions that established by manual or non PCE        +-----+-----+
      PLSP-ID=X7(Symbolic Path Name=Class A)       |          +----^---^---^-----+           |
      EPR Object(Peer Address=R1_A                 |               |   |   |                 |
                 Next Hop=R4_A)                    |               |   |   |                 |
                                                   |               |   |   |                 |
M1-R PCRpt Message:                                |               |   |   |                 |
     PLSP-ID=X7                                    | initiated
   configuration.

   BGP Peer Info Object-Class is TBD
   BGP Peer Info Object-Type is 1 for IPv4 and 2 for IPv6

   The format of the BGP Peer Info object body for IPv4(Object-Type=1)
   is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  +v-+                      Peer AS Number                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |
     EPR Object(Peer Address=R1_A                  +------------+ +---+R3+-------------------+                                                                                       )
                Next Hop=R4_A)   ETTL        |              Reserved                         |  +--+
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Local IP Address                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                   Peer IP Address                             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Additional TLVs                              |
                                                  +v-+      +--+
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        Figure 6: BGP Peer Info Object Body Format for IPv4

   The format of the BGP Peer Info object body for IPv6(Object-Type=2)
   is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Peer AS Number                           |       +--+    +-v+
                                                  |R1+------+R5++ +----------------+R6+----+R7|
                                                  ++-+      +--+
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   ETTL        |       +--+    +-++              Reserved                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |
M3  PCInitiate Message               Local IP Address (16 bytes)                     |           +---+       +---+
   +                                                               +
   |
    PLSP-ID=X2(Symbolic Path Name=Class A)                                                               |          +v-+
   +                                                               +
   |                                                               |  +v-+
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |
    EPR Object(Peer Address=R1_A                   +----------+R2+-+ +--------+R4+-----------+
               Next Hop=R1_A)                                                               |
   +                                                               +
   |               Peer IP Address (16 bytes)                      |
   +                                                               +
   |
M3-R PCRpt Message                                                               |
   +                                                               +
   |
     PLSP-ID=X2(Symbolic Path Name=Class A) <----------------------+                                                               |
     EPR Object(Peer Address=R1_A
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |
                Next Hop=R1_A)                  Additional TLVs                              |
                                                                           v
                                                    M2   PCInitiate Message
                                                         PLSP-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R1_A
                                                                    Next Hop=R2_A)

                                                    M2-R PCRpt Message
                                                         PLSP-ID=X4(Symbolic Path Name=Class A)
                                                         EPR Object(Peer Address=R1_A
                                                                    Next Hop=R2_A)
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 9: Explicit Route Establish Procedures(From R7 to R1)

   When PCC receives this object with the R bit set to 0 in SRP object
   in PCInitiate message, the PCC should install the explicit route 7: BGP Peer Info Object Body Format for IPv6

   Peer AS Number: 4 Bytes, to indicate the the peer.

   When PCC install successfully the explicit route AS number of Remote Peer.

   ETTL: 1 Bytes, to indicate the peer, it multi hop count for EBGP session.  It
   should report the result via the PCRpt messages, with this object
   included, be 0 and the corresponding SRP ignored when Local AS and LSP object.

   When PCC receives this object with the R bit Peer AS is same.

   Reserved: is set to 1 in SRP object
   in PCInitiate message, zero while sending, ignored on receipt..

   Local IP Address(4/16 Bytes): IP address of the PCC should clear local router, used to
   peer with other end router.  When Object-Type is 1, length is 4
   bytes; when Object-Type is 2, length is 16 bytes.

   Peer IP Address(4/16 Bytes): IP address of the explicit route peer router, used to the
   peer that indicated by this object.

   When PCC clear successfully the explicit route that indicated by this
   object, it should report the result via the PCRpt message, with this
   object included, and the corresponding SRP and LSP object.

   When PCC receives this object in PCUpd message, the PCC should update
   the explicit route according to info indicated in this object. local router.  When PCC updates the path successfully, it should report the result
   via the PCRpt message, Object-Type is 1, length is 4
   bytes; when Object-Type is 2, length is 16 bytes;

   Additional TLVs: TLVs that associated with this object included, and the
   corresponding SRP and LSP object.

   Upon the error occurs, the PCC SHOULD send the corresponding error object, can be used
   to convey other necessary information that defined in Section 8 for dynamic BGP session
   establishment.  Its definition is out of the current document.

7.3.  Explicit Peer Prefix Association Route Object

   The Explicit Peer Prefix Association Route object is defined to specify the IP
   prefixes that should be advertised explicit
   peer route to the corresponding peer. peer address on each device that is
   on the E2E assurance path.  This
   object Object should only be included and sent to all the head/end router of
   devices that locates on the
   end2end path. E2E assurance path that calculated by
   PCE.

   The prefixes information included in path established by this object MUST only should have higher priority than
   other path calculated by dynamic IGP protocol, but should be
   advertised to lower
   priority that the indicated peer, MUST not be advertised to other BGP
   peers. static route configured by manual or NETCONF
   channel.

   Explicit Peer Prefix Association Route Object-Class is TBD TBD.

   Explicit Peer Prefix Association Route Object-Type is 1 for IPv4 and 2 for IPv6

   The format of the Explicit Peer Prefix Association Route object body for IPv4(Object-Type=1)
   is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Peer       Route Priority        |          Reserved               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                IPv4 Peer Address                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   //           Next Hop Address to the IPv4 Prefix subobjects                         //
   | Peer Address           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Figure 10: 8: Explicit Peer Prefix Association Route Object Body Format for IPv4

   The format of Explicit Peer Route object body for IPv6(Object-Type=2)
   is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Peer IPv6 Address                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   //               IPv6 Prefix subobjects                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Figure 11: Peer Prefix Association Object Body Format for IPv6

   Peer IPv4 Address: 4 Bytes.  Identifies the peer IPv4 address that
   the associated prefixes will be sent to.

   IPv4 Prefix subojects: List of IPv4 Prefix subobjects that defined in
   [RFC3209], identify the prefixes that will be sent to the peer that
   identified by Peer IPv4 Address List.

   Peer IPv6 Address: 16 Bytes.  Identifies the peer IPv6 address that
   the associated prefixes will be sent to.

   IPv6 Prefix subojects: List of IPv6 Prefix subobjects that defined in
   [RFC3209], identify the prefixes that will be sent to the peer that
   identified by Peer IPv6 Address List.

   The detail procedures for the usage of this object is shown
   below(PCInitiate and PCRpt message pair, other message pairs are
   similar)

   The PCInitiate message should be sent to R1(M1) and R7(M2)
   respectively.

                                                M2  PCInitiate Message:
                                                    PLSP-ID=X7(Symbolic Path Name=Class A)
                                                    PPA Object(Peer IP=R1_A, Prefix=7_A)

                                                                                           <-----+
                                                M2-R  PCRpt Message:                             |
                                                      PLSP-ID=X7                                 |
                                                      PPA Object(Peer IP=R1_A, Prefix=7_A)       |
                                                                                                 |
                                                                                                 |
                                                                                                 |
                                                              +------------------+               |
M1   PCInitiate Message:                           +----------+       PCE        +-----------+   |
     PLSP-ID=X1(Symbolic Path Name=Class A)        |          +------------------+           |   |
     PPA Object(Peer IP=R7_A, Prefix=1_A)          | 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Route Priority        |           Reserved              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
                                        <----------+                                         +---+
M1-R PCRpt Message:
   +                                                               +
   |                      IPv6 Peer Address                        |
     PLSP-ID=X1
   +                                                               +
   |                  +--+                                                               |
     PPA Object(Peer IP=R7_A,Prefix=1_A)           +------------------+R3+-------------------+                                                                                        )
   +                                                               +
   |                  +--+                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
                                                  +v-+          +--+          +--+         +-v+
                                                  |R1+----------+R5+----------+R6+---------+R7|
                                                  ++-+          +--+          +--+         +-++
   +                                                               +
   |          Next Hop Address to the IPv6 Peer Address            |
   +                                                               +
   |                                                               |
   +                                                               +
   |            +--+          +--+                                                               |
                                                   +------------+R2+----------+R4+-----------+
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Figure 12: BGP Prefix Advertisement Procedures

   When PCC receives this object with the R bit set to 0 in SRP object
   in PCInitiate message, the PCC should send the prefixes indicated in 9: Explicit Peer Route Object Body Format for IPv6

   Route Priority: 2 Bytes, The priority of this object to the appointed BGP peer.

   When PCC sends successfully the prefixes to the appointed BGP peer,
   it explicit route.  The
   higher priority should report the result via the PCRpt messages, with this object
   included, and the corresponding SRP and LSP object.

   When PCC receives this object with be preferred by the R bit device.

   Reserved.: is set to 1 in SRP object
   in PCInitiate message, the PCC should withdraw the prefixes
   advertisement to zero while sending, ignored on receipt.

   Peer Address: To indicate the peer that indicated by this object.

   When PCC withdraws successfully the prefixes that indicated by this
   object, it should report address.

   Next Hop Address to the result via Peer: To indicate the PCRpt message, with this
   object included, and next hop address to the
   corresponding SRP and LSP object.

   When PCC receives this peer.

7.4.  Peer Prefix Association Object

   The Peer Prefix Association object in PCUpd message, it should update is defined to specify the
   BGP routes IP
   prefixes that should be advertised to the associated corresponding peer.

   When PCC updates the advertised BGP routes successfully, it  This
   object should
   report only be included and sent to the result via head/end router of the PCRpt message, with
   end2end path.

   The prefixes information included in this object included,
   and the corresponding SRP and LSP object.

   The IPv4 prefix MUST only be
   advertised via the IPv4 BGP session and to the IPv6 prefix indicated peer, MUST only NOT be advertised via the IPv6 to other BGP session.  If
   mismatch occur, an error should be reported.

   When the peer info that associated with the PLSP-ID
   peers.

   Peer Prefix Association Object-Class is not the same
   as TBD

   Peer Prefix Association Object-Type is 1 for IPv4 and 2 for IPv6
   The format of the peer info that indicated in this Peer Prefix Association object in PCC, a error should
   be reported via the PCRpt message.

   Upon the error occurs, body is as follows:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Peer IPv4 Address                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   //               IPv4 Prefix subobjects                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     Figure 10: Peer Prefix Association Object Body Format for IPv4

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Peer IPv6 Address                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   //               IPv6 Prefix subobjects                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Figure 11: Peer Prefix Association Object Body Format for IPv6

   Peer IPv4 Address: 4 Bytes.  Identifies the PCC SHOULD send peer IPv4 address that
   the corresponding error
   information associated prefixes will be sent to.

   IPv4 Prefix subojects: List of IPv4 Prefix subobjects that defined in Section 8

   The object type of
   [RFC3209], identify the above three objects should prefixes that will be identical sent to
   assure the prefixes from one address family are advertised via the peer belong to same address family, and the traffic is forwarded to that
   identified by Peer IPv4 Address List.

   Peer IPv6 Address: 16 Bytes.  Identifies the next hop also belong to same peer IPv6 address family.  If the mismatch
   occur, that
   the error should associated prefixes will be reported to the PCE.

   For one PLSP-ID on the PCC, the object type sent to.

   IPv6 Prefix subojects: List of PAL object should IPv6 Prefix subobjects that defined in
   [RFC3209], identify the prefixes that will be
   equal sent to object type of PPA object.  If not, the mismatch occurs and the related error should be reported. peer that
   identified by Peer IPv6 Address List.

8.  New Error-Types and Error-Values Defined

   A PCEP-ERROR object is used to report a PCEP error and is
   characterized by an Error-Type that specifies that type of error and
   an Error-value that provides additional information about the error.
   An additional Error-Type and several Error-values are defined to
   represent some the errors related to the newly defined objects, which
   are related to Native IP TE procedures.

          +============+===============+==============================+
          | Error-Type | Meaning       | Error-value                  |
          +============+===============+==============================+
          | TBD        | Native IP     |                              |
          |            | TE failure    |                              |
          +------------+---------------+------------------------------+
          |            |               | 0: Unassigned                |
          +------------+---------------+------------------------------+
          |            |               | 1: Peer AS not match         |
          +------------+---------------+------------------------------+
          |            |               | 2: Peer IP can't be reached  |
          +------------+---------------+------------------------------+
          |            |               | 3: Explicit Peer Address mismatch Route Error |
          +------------+---------------+------------------------------+
          |            |               | 4: PAL/PPA Object AF EPR/BPI Peer Info mismatch|
          +------------+---------------+------------------------------+
          |            |               | 5: PAL/EPR BPI/PPA Object AF mismatch|
          +------------+---------------+------------------------------+
          |            |               | 6: PPA/EPR object AF PPA/BPI Peer Info mismatch|
          +------------+---------------+------------------------------+
          |            |               | 7:                           |
          +------------+---------------+------------------------------+
          |            |               | 8:                           |
          +------------+---------------+------------------------------+
          |            |               | 8:                           |
          +------------+---------------+------------------------------+
          |            |               | 9:                           |
          +------------+---------------+------------------------------+
               Figure 13: 12: Newly defined Error-Type and Error-Value

9.  Management Consideration

   The information transferred in this draft is mainly used for the
   light weight BGP session setup, explicit route deployment and the
   prefix distribution.  The planning, allocation and distribution of
   the peer addresses within IGP should be accomplished in advanced and
   they are out of the scope of this draft.

   [RFC8232] describes the state synchronization procedure between
   stateful PCE and PCC.  The communication of PCE and PCC described in
   this draft should also follow this procedures, treat the three newly
   defined objects that associated with the same symbolic path name as
   the attribute of the same path in the LSP-DB.

   When PCE detects one or some of the PCCs are out of control, it
   should recompute and redeploy the traffic engineering path for native
   IP on the active PCCs.  When PCC detects that it is out of control of
   the PCE, it should clear the information that initiated by the PCE.

   The PCE should assures the avoidance of possible transient loop in
   such node failure when it deploy the explicit peer route on the PCCs.

10.  Security Considerations

   Service provider should consider the protection of PCE and their
   communication with the underlay devices, which is described in
   document [RFC5440] and [RFC8253]

11.  IANA Considerations

11.1.  PCEP Object Types

   IANA is requested to allocate new registry for the PCEP Object Type:

   Object-Type

   Object-Class Value       Name                        Reference
   TBD               CCI Object                      This document
                     Object-Type
                        TBD: Native IP

   TBD               BGP Peer Info                   This document
                     Object-Type
                        1: IPv4 address
                        2: IPv6 address

   TBD               Explicit Peer Route             This document
                     Object-Type
                        1: IPv4 address
                        2: IPv6 address

   TBD               Peer Prefix Association         This document
                     Object-Type
                        1: IPv4 address
                        2: IPv6 address

12.  Contributor

   Dhruv Dhody has contributed the contents of this draft.

13.  Acknowledgement

   Thanks Dhruv Dhody, Mike Koldychev, Siva Sivabalan, Adam Simpson for his valuable
   suggestions and comments.

13.

14.  Normative References

   [I-D.ietf-pce-pcep-extension-for-pce-controller]
              Li, Z., Peng, S., Negi, M., Zhao, Q., and C. Zhou, "PCEP
              Procedures and Protocol Extensions for Using PCE as a
              Central Controller (PCECC) of LSPs", draft-ietf-pce-pcep-
              extension-for-pce-controller-07 (work in progress),
              September 2020.

   [I-D.ietf-teas-pce-native-ip]
              Wang, A., Khasanov, B., Zhao, Q., and H. Chen, "PCE in
              Native IP Network", draft-ietf-teas-pce-native-ip-11 (work
              in progress), August 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>.

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

   [RFC5440]  Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
              Element (PCE) Communication Protocol (PCEP)", RFC 5440,
              DOI 10.17487/RFC5440, March 2009,
              <https://www.rfc-editor.org/info/rfc5440>.

   [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>.

   [RFC8231]  Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
              Computation Element Communication Protocol (PCEP)
              Extensions for Stateful PCE", RFC 8231,
              DOI 10.17487/RFC8231, September 2017,
              <https://www.rfc-editor.org/info/rfc8231>.

   [RFC8232]  Crabbe, E., Minei, I., Medved, J., Varga, R., Zhang, X.,
              and D. Dhody, "Optimizations of Label Switched Path State
              Synchronization Procedures for a Stateful PCE", RFC 8232,
              DOI 10.17487/RFC8232, September 2017,
              <https://www.rfc-editor.org/info/rfc8232>.

   [RFC8253]  Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody,
              "PCEPS: Usage of TLS to Provide a Secure Transport for the
              Path Computation Element Communication Protocol (PCEP)",
              RFC 8253, DOI 10.17487/RFC8253, October 2017,
              <https://www.rfc-editor.org/info/rfc8253>.

   [RFC8281]  Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path
              Computation Element Communication Protocol (PCEP)
              Extensions for PCE-Initiated LSP Setup in a Stateful PCE
              Model", RFC 8281, DOI 10.17487/RFC8281, December 2017,
              <https://www.rfc-editor.org/info/rfc8281>.

   [RFC8283]  Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An
              Architecture for Use of PCE and the PCE Communication
              Protocol (PCEP) in a Network with Central Control",
              RFC 8283, DOI 10.17487/RFC8283, December 2017,
              <https://www.rfc-editor.org/info/rfc8283>.

   [RFC8408]  Sivabalan, S., Tantsura, J., Minei, I., Varga, R., and J.
              Hardwick, "Conveying Path Setup Type in PCE Communication
              Protocol (PCEP) Messages", RFC 8408, DOI 10.17487/RFC8408,
              July 2018, <https://www.rfc-editor.org/info/rfc8408>.

   [RFC8735]  Wang, A., Huang, X., Kou, C., Li, Z., and P. Mi,
              "Scenarios and Simulation Results of PCE in a Native IP
              Network", RFC 8735, DOI 10.17487/RFC8735, February 2020,
              <https://www.rfc-editor.org/info/rfc8735>.

Authors' Addresses

   Aijun Wang
   China Telecom
   Beiqijia Town, Changping District
   Beijing, Beijing  102209
   China

   Email: wangaj3@chinatelecom.cn

   Boris Khasanov
   Huawei Technologies,Co.,Ltd
   Moskovskiy Prospekt 97A
   St.Petersburg  196084
   Russia

   Email: khasanov.boris@huawei.com bhassanov@yahoo.com
   Sheng Fang
   Huawei Technologies,Co.,Ltd
   Huawei Bld., No.156 Beiqing Rd.
   Beijing
   China

   Email: fsheng@huawei.com

   Ren Tan
   Huawei Technologies,Co.,Ltd
   Huawei Bld., No.156 Beiqing Rd.
   Beijing
   China

   Email: tanren@huawei.com

   Chun Zhu
   ZTE Corporation
   50 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: zhu.chun1@zte.com.cn