PCE Working Group                                                A. Wang
Internet-Draft                                             China Telecom
Intended status: Standards Track                             B. Khasanov
Expires: December 9, 2021 28 January 2022                                      Yandex LLC
                                                                 S. Fang
                                                                  R. Tan
                                             Huawei Technologies,Co.,Ltd
                                                                  C. Zhu
                                                         ZTE Corporation
                                                            June 7,
                                                            27 July 2021

                  PCEP Extension for Native IP Network
               draft-ietf-pce-pcep-extension-native-ip-14
               draft-ietf-pce-pcep-extension-native-ip-15

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 [RFC8821].  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

   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 December 9, 2021. 28 January 2022.

Copyright Notice

   Copyright (c) 2021 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) (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.  Conventions used in this document . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Capability Advertisemnt . . . . . . . . . . . . . . . . . . .   4
     4.1.  Open message  . . . . . . . . . . . . . . . . . . . . . .   4
   5.  PCEP messages . . . . . . . . . . . . . . . . . . . . . . . .   4
     5.1.  The PCInitiate message  . . . . . . . . . . . . . . . . .   5
     5.2.  The PCRpt message . . . . . . . . . . . . . . . . . . . .   6
   6.  PCECC Native IP TE Procedures . . . . . . . . . . . . . . . .   7
     6.1.  BGP Session Establishment Procedures  . . . . . . . . . .   7
     6.2.  Explicit Route Establish Procedures . . . . . . . . . . .   9
     6.3.  BGP Prefix Advertisement Procedures . . . . . . . . . . .  12
   7.  New PCEP Objects  . . . . . . . . . . . . . . . . . . . . . .  13
     7.1.  CCI Object  . . . . . . . . . . . . . . . . . . . . . . .  13
     7.2.  BGP Peer Info Object  . . . . . . . . . . . . . . . . . .  14
     7.3.  Explicit Peer Route Object  . . . . . . . . . . . . . . .  17
     7.4.  Peer Prefix Advertisement Object  . . . . . . . . . . . .  19
   8.  End to End Path Protection  . . . . . . . . . . . . . . . . .  21
   9.  Re-Delegation and Clean up  . . . . . . . . . . . . . . . . .  21
   10. BGP Considerations  . . . . . . . . . . . . . . . . . . . . .  21
   11. New Error-Types and Error-Values Defined  . . . . . . . . . .  22
   12. Deployment Considerations . . . . . . . . . . . . . . . . . .  22  23
   13. Security Considerations . . . . . . . . . . . . . . . . . . .  23
   14. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  23
     14.1.  Path Setup Type Registry . . . . . . . . . . . . . . . .  23  24
     14.2.  PCECC-CAPABILITY sub-TLV's Flag field  . . . . . . . . .  24
     14.3.  PCEP Object Types  . . . . . . . . . . . . . . . . . . .  24
     14.4.  PCEP-Error Object  . . . . . . . . . . . . . . . . . . .  24  25
   15. Contributor . . . . . . . . . . . . . . . . . . . . . . . . .  25
   16. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  25
   17. Normative References  . . . . . . . . . . . . . . . . . . . .  25
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  27

1.  Introduction

   Generally, Multiprotocol Label Switching Traffic Engineering (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.  In Segment Routing either IGP extensions
   or BGP are used to steer a packet through an SR Policy instantiated
   as an ordered list of instructions called "segments".  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.  [RFC8821]
   describes the architecture and solution philosophy for the E2E
   traffic assurance in Native IP network via 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 info, peer prefix
   advertisement 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 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 Advertisement

   o

   *  QoS: Quality of Service

4.  Capability Advertisemnt

4.1.  Open message

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

   This document defines a new Path Setup Type (PST) [RFC8408] for
   Native-IP, as follows:

   o

   *  PST = TBD1: Path is a Native IP path as per [RFC8821].

   A PCEP speaker MUST indicate its support of the function described in
   this document by 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 defined in PCECC-CAPABILITY sub-TLV for
   Native IP:

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

   If a PCEP speaker receives the PATH-SETUP-TYPE-CAPABILITY TLV with
   the newly defined path setup type, but without the N bit set in
   PCECC-CAPABILITY sub-TLV, it MUST:

   o

   *  Send a PCErr message with Error-Type=10(Reception of an invalid
      object) and Error-Value TBD3(PCECC NATIVE-IP-TE-CAPABILITY bit is
      not set).

   o

   *  Terminate the PCEP session

5.  PCEP messages

   PCECC Native IP TE solution utilizing the existing PCE LSP Initate
   Request message(PCInitiate)[RFC8281], and PCE Report message(PCRpt)
   [RFC8281] to accomplish the multi BGP sessions establishment, E2E TE
   path deployment, and route prefixes advertisement among different BGP
   sessions.  A new PST for Native-IP is used to indicate the path setup
   based on TE in Native IP networks.

   The extended PCInitiate message described in
   [I-D.ietf-pce-pcep-extension-for-pce-controller] is used to download
   or cleanup central controller's instructions (CCIs).

   [I-D.ietf-pce-pcep-extension-for-pce-controller] specify an object
   called CCI for the encoding of central controller's instructions.
   This document specify a new CCI object-type for Native IP.  The PCEP
   messages are extended in this document to handle the PCECC operations
   for Native IP.  Three new PCEP Objects (BGP Peer Info (BPI) Object,
   Explicit Peer Route (EPR) Object and Peer Prefix Advertisement (PPA)
   Object) are defined in this document.  Refer to (Section 7) toSection 7 for detail
   object 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 support Native-IP CCI.

   The format of the 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 per
         [I-D.ietf-pce-pcep-extension-for-pce-controller].
         <PCE-initiated-lsp-instantiation> and
         <PCE-initiated-lsp-deletion> are as per
         [RFC8281].

        The LSP and SRP objects are defined in [RFC8231].

   When PCInitiate message is used create Native IP instructions, the
   SRP, LSP and CCI objects MUST be present.  The error handling for
   missing SRP, LSP or CCI object is as per
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Further only one
   of BPI, EPR, or PPA object MUST be present.  The PLSP-ID within the
   LSP object should be set by PCC uniquely according to the Symbolic
   Path Name TLV that included in the CCI object.  The Symbolic Path
   Name is used by the PCE/PCC to identify uniquely the E2E native IP TE
   path.

   If none of them are present, the receiving PCC MUST send a PCErr
   message with Error-type=6 (Mandatory Object missing) and Error-
   value=TBD4 (Native IP object missing).  If there are more than one of
   BPI, EPR or PPA object are presented, the receiving PCC MUST send a
   PCErr message with Error-type=19(Invalid Operation) and Error-
   value=TBD5(Only one of the BPI, EPR or PPA object can be included in
   this message).

   To cleanup the 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 [RFC8231].

   The error handling for missing CCI object is as per
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Further only one
   of BPI, EPR, or PPA object MUST be present.

   If none of them are present, the receiving PCE MUST send a PCErr
   message with Error-type=6 (Mandatory Object missing) and Error-
   value=TBD4 ( Native IP object missing).  If there are more than one
   of BPI, EPR or PPA object are presented, the receiving PCE MUST send
   a PCErr message with Error-type=19(Invalid Operation) and Error-
   value=TBD5(Only one of the BPI, EPR or PPA object can be included in
   this message).

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, by
   using the PCInitiate and PCRpt message pair. pair is shown below.

   The PCInitiate message should be sent to PCC which acts as BGP router
   and
   and/or route reflector(RR).

   In the example in Figure 1, it if the router R1 and R7 are within one AS
   and R3 acts as the route reflector, PCInitiate message should be sent
   to R1(M1), route reflector clients R1(M1) and R7(M4), and the route reflector
   R3(M2 & M3) respectively.  For inter-AS scenario, such message can be
   sent directly to the ASBR router to build EBGP session.

   PCInitiate message creates an auto-configuration function for these
   BGP peers providing the indicated Peer AS and R7(M4), when R3 acts as RR. the Local/Peer IP
   Address.

   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 with the indicated Peer AS and Local/Peer IP address.

   When PCC creates successfully the BGP session that is indicated by
   the associated information, it should report the result via the PCRpt
   messages, with BPI object and the corresponding SRP and CCI object
   included.

   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.

                                +------------------+
                    +-----------+       PCE        +----------+
                    |           +--------^---------+          |
                    |                    |                    |
                                M2/M2-R & M3/M3-R
                    |                    |                    |
                    |               +---v---+                 |
                    +---------------+ R3(RR)+-----------------+
                    |               +-------+                 |
                 M1/M1-R                                   M4/M4-R
                    |                                         |
                   +v-+          +--+          +--+         +-v+
                   |R1+----------+R5+----------+R6+---------+R7|
                   ++-+          +--+          +--+         +-++
                    |                                         |
                    |            +--+          +--+           |
                    +------------+R2+----------+R4+-----------+
                                 +--+          +--+
          Figure 1: BGP Session Establishment Procedures(R3 act as RR)

   The message number, message peers, message type and message key
   parameters in the above figures are shown in below table:

                     Table 1: Message Information
   +-------------------------------------------------------------+
   | No.| Peers|    Type  |     Message Key Parameters           |
   +-------------------------------------------------------------+
   |M1  |PCE/R1|PCInitiate|CC-ID=X1(Symbolic Path Name=Class A)  |
   |M1-R|      |PCRpt     |BPI Object(Local_IP=R1_A,Peer_IP=R3_A)|
   +-------------------------------------------------------------+
   |M2  |PCE/R3|PCInitiate|CC-ID=X2(Symbolic Path Name=Class A)  |
   |M2-R|      |PCRpt     |BPI Object(Local_IP=R3_A,Peer_IP=R1_A)|
   +-------------------------------------------------------------+
   |M3  |PCE/R3|PCInitiate|CC-ID=X3(Symbolic Path Name=Class A)  |
   |M3-R|      |PCRpt     |BPI Object(Local_IP=R3_A,Peer_IP=R7_A)|
   +-------------------------------------------------------------+
   |M4  |PCE/R7|PCInitiate|CC-ID=X4(Symbolic Path Name=Class A)  |
   |M4-R|      |PCRpt     |BPI Object(Local_IP=R7_A,Peer_IP=R3_A)|
   +-------------------------------------------------------------+

   If the PCC cannot establish the BGP session that required by this
   object, it should report the error values via PCErr message with the
   newly defined error type(Error-type=TBD6) and error value(Error-
   value=TBD7, Peer AS not match; or Error-Value=TBD8, Peer IP can't be
   reached), which is indicated in Section 11

   If the Local IP Address or Peer IP Address within BPI object is used
   in other existing BGP sessions, the PCC should report such error
   situation via PCErr message with Err-type=TBD6 and error value(Error-
   value=TBD9, Local IP is in use; Error-value=TBD10, Remote IP is in
   use).

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 and
   the corresponding SRP and CCI object included.

   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.

                             +------------------+
                  +----------+       PCE        +
                  |          +----^-----------^-+
                  |               |           |
                  |               |           |
                  |               | +------+  |
                  +-----------------+R3(RR)+--|-------------+
              M1/M1-R             | +------+  |             |
                  |               |           |             |
                 +v-+      +--+   |           |   +--+    +--+
                 |R1+------+R5+---+-----------|---+R6+----+R7|
                 ++-+      +--+   |           |   +--+    +-++
                  |            M2/M2-R      M3/M3-R         |
                  |               |           |             |
                  |            +--v--+     +--v-+           |
                  +------------+- R2 +-----+ R4 +-----------+
                               +--+--+     +--+-+
         Figure 2: Explicit Route Establish Procedures(From R1 to R7)

   The message number, message peers, message type and message key
   parameters in the above figures are shown in below table:

                       Table 2: Message Information
   +------------------------------------------------------------------+
   | No.|Peers |   Type   |     Message Key Parameters                |
   +------------------------------------------------------------------+
   |M1  |PCE/R1|PCInitiate|CC-ID=X1(Symbolic Path Name=Class A)       |
   |M1-R|      |PCRpt     |EPR Object(Peer Address=R7_A,Next Hop=R2_A)|
   +------------------------------------------------------------------+
   |M2  |PCE/R2|PCInitiate|CC-ID=X2(Symbolic Path Name=Class A)       |
   |M2-R|      |PCRpt     |EPR Object(Peer Address=R7_A,Next Hop=R4_A)|
   +------------------------------------------------------------------+
   |M3  |PCE/R4|PCInitiate|CC-ID=X3(Symbolic Path Name=Class A)       |
   |M3-R|      |PCRpt     |EPR Object(Peer Address=R7_A,Next Hop=R7_A)|
   +------------------------------------------------------------------+
                       +------------------+
                       +       PCE        +-----------+
                       +----^-----------^-+           |
                            |           |             |
                            |           |             |
                            | +------+  |             |
            +-----------------+R3(RR)+--|-------------+
            |               | +------+  |         M1/M1-R
            |               |           |             |
           +--+      +--+   |           |   +--+    +-v+
           |R1+------+R5+---+-----------|---+R6+----+R7|
           ++-+      +--+   |           |   +--+    +-++
            |            M3/M3-R      M2/M2-R         |
            |               |           |             |
            |            +--v--+     +--v-+           |
            +------------+- R2 +-----+ R4 +-----------+
                         +--+--+     +--+-+
    Figure 3: Explicit Route Establish Procedures(From R7 to R1)

   The message number, message peers, message type and message key
   parameters in the above figures are shown in below table:

                       Table 3: Message Information
   +------------------------------------------------------------------+
   |No. |Peers |   Type   |     Message Key Parameters                |
   +------------------------------------------------------------------+
   |M1  |PCE/R7|PCInitiate|CC-ID=X1(Symbolic Path Name=Class A)       |
   |M1-R|      |PCRpt     |EPR Object(Peer Address=R1_A,Next Hop=R4_A)|
   +------------------------------------------------------------------+
   |M2  |PCE/R4|PCInitiate|CC-ID=X2(Symbolic Path Name=Class A)       |
   |M2-R|      |PCRpt     |EPR Object(Peer Address=R1_A,Next Hop=R2_A)|
   +------------------------------------------------------------------+
   |M3  |PCE/R2|PCInitiate|CC-ID=X3(Symbolic Path Name=Class A)       |
   |M3-R|      |PCRpt     |EPR Object(Peer Address=R1_A,Next Hop=R1_A)|
   +------------------------------------------------------------------+

   In order to avoid the transient loop during the deploy of explicit
   peer route, the EPR object should be sent to the PCCs in the reverse
   order of the E2E path.  To remove the explicit peer route, the EPR
   object should be sent to the PCCs in the same order of E2E path.

   To accomplish ECMP effects, the PCE can send multiple EPR objects to
   the same node, with the same route priority and peer address value
   but different next hop addresses.

   The PCC should verify that the next hop address is reachable.  Upon
   the error occurs, the PCC SHOULD send the corresponding error via
   PCErr message, with an error information (Error-type=TBD6, Error-
   value=TBD12, Explicit Peer Route Error) that defined in Section 11.

   When the peer info is not the same as the peer info that indicated in
   BPI object in PCC for the same path that is identified by Symbolic
   Path Name TLV, an error (Error-type=TBD6, Error-value=17, EPR/BPI
   Peer Info mismatch) should be reported via the PCErr message.

6.3.  BGP Prefix Advertisement Procedures

   The detail procedures for BGP prefix advertisement are shown below,
   using PCInitiate and PCRpt message pair.

   The PCInitiate message should be sent to PCC that acts as BGP peer
   router only.  In the example, it should be sent to R1(M1) or R7(M2)
   respectively.

   When PCC receives the PPA and the CCI object (with the R bit set to 0
   in SRP object) in PCInitiate message, the PCC should send the
   prefixes indicated in this object to the appointed BGP peer.

   When PCC sends successfully the prefixes to the appointed BGP peer,
   it should report the result via the PCRpt messages, with PPA object
   and the corresponding SRP and CCI object included.

   When PCC receives the PPA and the CCI object with the R bit set to 1
   in SRP object in PCInitiate message, the PCC should withdraw the
   prefixes advertisement to the peer that indicated by this object.

   When PCC withdraws successfully the prefixes that indicated by this
   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 advertised via allowed AFI/SAFI for the IPv4 BGP session should be 1/1(IPv4
   prefix) and the IPv6 prefix MUST only be advertised via allowed AFI/SAFI for the IPv6 BGP session. session should be
   2/1(IPv6 prefix).  If mismatch occur, an error(Error-type=TBD6,
   Error-value=TBD18, BPI/PPR address family mismatch) should be
   reported via PCErr message.

   When the peer info is not the same as the peer info that indicated in
   BPI object in PCC for the same path that is identified by Symbolic
   Path Name TLV, an error (Error-type=TBD6, Error-value=TBD19, PPA/BPI
   peer info mismatch) should be reported via the PCErr message.

                 +------------------+
      +----------+       PCE        +-----------+
      |          +------------------+           |
      |                  +--+                   |
      +------------------+R3+-------------------+
     M1&M1-R             +--+                M2&M2-R
      |                                         |
      +v-+          +--+          +--+         +-v+
      |R1+----------+R5+----------+R6+---------+R7|
      ++-+          +--+          +--+         +-++
      |                                         |
      |                                         |
      |            +--+          +--+           |
      +------------+R2+----------+R4+-----------+
      Figure 4: BGP Prefix Advertisement Procedures

                           Table 4: Message Information
     +-----------------------------------------------------------+
     |No. | Peers|    Type  |  Message Key Parameters            |
     +-----------------------------------------------------------+
     |M1  |PCE/R1|PCInitiate|CC-ID=X1(Symbolic Path Name=Class A)|
     |M1-R|      |PCRpt     |PPA Object(Peer IP=R7_A,Prefix=1_A) |
     +-----------------------------------------------------------+
     |M2  |PCE/R7|PCInitiate|CC-ID=X2(Symbolic Path Name=Class A)|
     |M2-R|      |PCRpt     |PPA Object(Peer IP=R1_A,Prefix=7_A) |
     +-----------------------------------------------------------+

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

   The 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 Native-IP.

   CCI Object-Type is TBD13 for Native-IP as 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            CC-ID                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Reserved             |             Flags             |
   +---------------------------------------------------------------+
   |                                                               |
   //                        Optional TLV                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

           Figure 5: CCI Object for Native IP

                                  Figure 1

   The field CC-ID is as described in
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Following fields
   are defined for CCI Object-Type TBD13

   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 Symbolic Path Name TLV [RFC8231] MUST be included in the CCI
   Object-Type TBD13 to identify the E2E 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 information about the
   peer that the PCC should establish the BGP relationship with.  This
   object should only be included and sent to the 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 head router, RR and end router
   respectively.

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

   By default, the Local/Peer IP address SHOULD be dedicated to the
   usage of native IP TE solution, and SHOULD NOT be used by other BGP
   sessions that established by manual or non PCE initiated
   configuration.

   BGP Peer Info Object-Class is TBD14
   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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Peer AS Number                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   ETTL        |              Reserved                       |T|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Local IP Address                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                   Peer IP Address                             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               Tunnel Source IP Address                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               Tunnel Destination IP Address                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Additional TLVs                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        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                           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   ETTL        |              Reserved                       |T|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |               Local IP Address (16 bytes)                     |
   +                                                               +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |               Peer IP Address (16 bytes)                      |
   +                                                               +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |          Tunnel Source IP Address (16 bytes)                  |
   +                                                               +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |          Tunnel Destination IP Address (16 bytes)             |
   +                                                               +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Additional TLVs                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
         Figure 7: BGP Peer Info Object Body Format for IPv6

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

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

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

   T bit: Indicates whether the traffic that associated with the
   prefixes advertised via this BGP session is transported via IPinIP
   tunnel (when T bit is set) or not (when T bit is clear).

   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;

   Tunnel Source IP Address(4/16 Bytes): IP address of the tunnel
   source, should be owned by the local router.  When Object-Type is 1,
   length is 4 bytes; when Object-Type is 2, length is 16 bytes.

   Tunnel Destination IP Address(4/16 Bytes): IP address of the tunnel
   destination, should be owned by the peer router.  When Object-Type is
   1, length is 4 bytes; when Object-Type is 2, length is 16 bytes.
   Should be different from the Peer IP Address.

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

   When PCC receives BPI object, with Object-Type=1, it should try to
   establish BGP session with the peer in AFI/SAFI=1/1; when PCC
   receives BPI object with Object-Type=2, it should try to establish
   the BGP session with the peer in AFI/SAFI=2/1.  Other BGP
   capabilities,for example, Graceful Restart(GR) that enhance the BGP
   performance should also be negotiated and used by default.

7.3.  Explicit Peer Route Object

   The Explicit Peer Route object is defined to specify the explicit
   peer route to the corresponding peer address on each device that is
   on the E2E assurance path.  This Object should be sent to all the
   devices that locates on the E2E assurance path that calculated by
   PCE.

   The path established by this object should have higher priority than
   other path calculated by dynamic IGP protocol, but should be lower
   priority than the static route configured by manual or NETCONF or by
   other means.

   Explicit Peer Route Object-Class is TBD15.

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

   The format of Explicit Peer 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Route Priority        |          Reserved               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               Peer/Tunnel Destination Address                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |    Next Hop Address to the Peer/Tunnel Destination Address    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Additional TLVs                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Figure 8: Explicit Peer 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Route Priority        |           Reserved              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |           Peer Address/Tunnel Destination Address             |
   +                                                               +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   +                                                               +
   |     Next Hop Address to the Peer/Tunnel Destination Address   |
   +                                                               +
   |                                                               |
   +                                                               +
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Additional TLVs                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       Figure 9: Explicit Peer Route Object Body Format for IPv6

   Route Priority: 2 Bytes, The priority of this explicit route.  The
   higher priority should be preferred by the device.  This field is
   used to indicate the backup path at each hop.

   Reserved.:

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

   Peer/Tunnel Destination Address: To indicate the peer address(4/16
   Bytes).  When T bit is set in the associated BPI object, use the
   tunnel destination address in BPI object; when T bit is clear, use
   the peer address in BPI object.

   Next Hop Address to the Peer/Tunnel Destination Address: To indicate
   the next hop address(4/16 Bytes) to the corresponding peer/tunnel
   destination address.

   Additional TLVs: TLVs that associated with this object, can be used
   to convey other necessary information for explicit peer path
   establishment.  Its definition is  Their definitions are out of the current document.

7.4.  Peer Prefix Advertisement Object

   The Peer Prefix Advertisement object is defined to specify the IP
   prefixes that should be advertised to the corresponding peer.  This
   object should only be included and sent to the head/end router of the
   end2end path.

   The prefixes information included in this object MUST only be
   advertised to the indicated peer, MUST NOT be advertised to other BGP
   peers.

   Peer Prefix Advertisement Object-Class is TBD16

   Peer Prefix Advertisement Object-Type is 1 for IPv4 and 2 for IPv6

   The format of the Peer Prefix Advertisement object 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                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Additional TLVs                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     Figure 10: Peer Prefix Advertisement 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                         //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Additional TLVs                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      Figure 11: Peer Prefix Advertisement 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.

   Additional TLVs: TLVs that associated with this object, can be used
   to convey other necessary information for prefixes advertisement.
   Its definition is
   Their definitions are out of the current document.

8.  End to End Path Protection

   [RFC8697] defines the path associations procedures between sets of
   Label Switched Path (LSP).  Such procedures can also be used for the
   E2E path protection.  To accomplish this, the PCE should attach the
   ASSOCIATION object with the EPR object in the PCInitiate message,
   with the association type set to 1 (Path Protection Association).
   The Extended Association ID that included within the Extended
   Association ID TLV, which is included in the ASSOCIATION object,
   should be set to the Symbolic Path Name of different E2E path.  This
   PCinitiate should be sent to the head-end of the E2E path.

   The head-end of the path can use the existing path detection
   mechanism,
   mechanism(for example, Bidirectional Forwarding Detection [RFC5880]),
   to monitor the status of the active path.  Once it detects the
   failure, it can switch the backup protection path immediately.

9.  Re-Delegation and Clean up

   In case of a PCE failure, a new PCE can gain control over the central
   controller instructions.  As per the PCEP procedures in [RFC8281],
   the State Timeout Interval timer is used to ensure that a PCE failure
   does not result in automatic and immediate disruption for the
   services.  Similarly, as per
   [I-D.ietf-pce-pcep-extension-for-pce-controller], the central
   controller instructions are not removed immediately upon PCE failure.
   Instead, they could be re-delegated to the new PCE before the
   expiration of this timer, or be cleaned up on the expiration of this
   timer.  The allows for network clean up without manual intervention.
   The PCC MUST support the removal of CCI as one of the behaviors
   applied on expiration of the State Timeout Interval timer.

10.  BGP Considerations

   This draft defines the procedures and objects to create the BGP
   sessions and advertises the associated prefixes dynamically.  Only
   the key information, for example peer IP addresses, peer AS number
   are exchanged via the PCEP protocol.  Other parameters that are
   needed for the BGP session setup should be derived from their default
   values, as described in Section 7.2.  Upon receives such key
   information, the BGP module on the PCC should try to accomplish the
   task that appointed by the PCEP protocol and report the status to the
   PCEP modules.

   There is no influence to current implementation of BGP Finite State
   Machine(FSM).  The PCEP cares only the success and failure status of
   BGP session, and act upon such information accordingly.

   The error handling procedures related to incorrect BGP parameters are
   specified in Section 6.1, Section 6.2, and Section 6.3.  The handling
   of the dynamic BGP sessions and associated prefixes on PCE failure is
   described in Section 9.

11.  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                  |
       +============+===============+=====================================+
       | TBD6       | Native IP     |                                     |
       |            | TE failure    |                                     |
       +------------+---------------+-------------------------------------+
       |            |               | 0: Unassigned                       |
       +------------+---------------+-------------------------------------+
       |            |               |TBD7: Peer AS not match              |
       +------------+---------------+-------------------------------------+
       |            |               |TBD8:Peer IP can't be reached        |
       +------------+---------------+-------------------------------------+
       |            |               |TBD9:Local IP is in use              |
       +------------+---------------+-------------------------------------+
       |            |               |TBD10:Remote IP is in use            |
       +------------+---------------+-------------------------------------+
       |            |               |TBD11:Exist BGP session broken       |
       +------------+---------------+-------------------------------------+
       |            |               |TBD12:Explicit Peer Route Error      |
       +------------+---------------+-------------------------------------+
       |            |               |TBD17:EPR/BPI Peer Info mismatch     |
       +------------+---------------+-------------------------------------+
       |            |               |TBD18:BPI/PPA Address Family mismatch|
       +------------+---------------+-------------------------------------+
       |            |               |TBD19:PPA/BPI Peer Info mismatch     |
       +------------+---------------+-------------------------------------+

            Figure 12: Newly defined Error-Type and Error-Value

12.  Deployment Considerations

   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.

   If the established BGP session is broken after some time, the PCC
   should also report such error via PCErr message with Err-type=TBD6
   and error value(Error-value=TBD11, Existing BGP session is broken).
   Upon receiving such PCErr message, the PCE should clear the prefixes
   advertisement on the previous BGP session, clear the explicit peer
   route to the previous peer address; select other Local_IP/Peer_IP
   pair to establish the new BGP session, deploy the explicit peer route
   to the new peer address, and advertises the prefixes on the new BGP
   session.

13.  Security Considerations

   The setup of BGP sessions, prefix advertisement, and explicit peer
   route establishment are all controlled by the PCE.  See [RFC4271] and
   [RFC4272] for BGP security considerations.  Security consideration
   part in [RFC5440] and [RFC8231] should be considered.  To prevent a
   bogus PCE sending harmful messages to the network nodes, the network
   devices should authenticate the validity of the PCE and ensure a
   secure communication channel between them.  Mechanisms described in
   [RFC8253] should be used.

14.  IANA Considerations
14.1.  Path Setup Type Registry

   [RFC8408] created a sub-registry within the "Path Computation Element
   Protocol (PCEP) Numbers" registry called "PCEP Path Setup Types".
   IANA is requested to allocate a new code point within this registry,
   as follows:

   Value             Description                       Reference
   TBD1           Native IP TE Path                  This document

14.2.  PCECC-CAPABILITY sub-TLV's Flag field

   [I-D.ietf-pce-pcep-extension-for-pce-controller] created a sub-
   registry within the "Path Computation Element Protocol (PCEP)
   Numbers" registry to manage the value of the PCECC-CAPABILITY sub-
   TLV's 32-bits Flag field.  IANA is requested to allocate a new bit
   position within this registry, as follows:

   Value             Description                       Reference
   TBD2(N)        NATIVE-IP-TE-CAPABILITY           This document

14.3.  PCEP Object Types

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

   Object-Class Value       Name                        Reference
   44                CCI Object                      This document
                     Object-Type
                        TBD13: Native IP

   TBD14             BGP Peer Info                   This document
                     Object-Type
                        1: IPv4 address
                        2: IPv6 address

   TBD15             Explicit Peer Route             This document
                     Object-Type
                        1: IPv4 address
                        2: IPv6 address

   TBD16             Peer Prefix Advertisement       This document
                     Object-Type
                        1: IPv4 address
                        2: IPv6 address

14.4.  PCEP-Error Object

   IANA is requested to allocate new error types and error values within
   the "PCEP-ERROR Object Error Types and Values" sub-registry of the
   PCEP Numbers registry for the following errors::

Error-Type       Meaning                      Error-value                                                             Reference
6           Mandatory Object missing
                                      TBD4:Native IP object missing                                                This document

10          Reception of an invalid object
                                      TBD3:PCECC NATIVE-IP-TE-CAPABILITY bit is not set                            This document

19          Invalid Operation
                                      TBD5:Only one of the BPI,EPR or PPA object can be included in this message   This document

TBD6        Native IP TE failure                                                                                   This document
                                      TBD7:Peer AS not match
                                      TBD8:Peer IP can't be reached
                                      TBD9:Local IP is in use
                                      TBD10:Remote IP is in use
                                      TBD11:Exist BGP session broken
                                      TBD12:Explicit Peer Route Error
                                      TBD17:EPR/BPI Peer Info mismatch
                                      TBD18:BPI/PPA Address Family mismatch
                                      TBD19:PPA/BPI Peer Info mismatch

15.  Contributor

   Dhruv Dhody has contributed the contents of this draft.

16.  Acknowledgement

   Thanks Mike Koldychev, Susan Hares, Siva Sivabalan, Adam Simpson for
   his valuable suggestions and comments.

17.  Normative References

   [I-D.ietf-pce-pcep-extension-for-pce-controller]
              Li, Z., Peng, S., Negi, M. S., Zhao, Q., and C. Zhou,
              "PCEP
              "Path Computation Element Communication Protocol (PCEP)
              Procedures and Protocol Extensions for Using the PCE as a Central
              Controller (PCECC) of LSPs", draft-ietf-pce-
              pcep-extension-for-pce-controller-14 (work Work in progress), Progress, Internet-
              Draft, draft-ietf-pce-pcep-extension-for-pce-controller-
              14, 5 March 2021. 2021, <https://www.ietf.org/archive/id/draft-
              ietf-pce-pcep-extension-for-pce-controller-14.txt>.

   [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>.

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

   [RFC4272]  Murphy, S., "BGP Security Vulnerabilities Analysis",
              RFC 4272, DOI 10.17487/RFC4272, January 2006,
              <https://www.rfc-editor.org/info/rfc4272>.

   [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>.

   [RFC5880]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD)", RFC 5880, DOI 10.17487/RFC5880, June 2010,
              <https://www.rfc-editor.org/info/rfc5880>.

   [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>.

   [RFC8697]  Minei, I., Crabbe, E., Sivabalan, S., Ananthakrishnan, H.,
              Dhody, D., and Y. Tanaka, "Path Computation Element
              Communication Protocol (PCEP) Extensions for Establishing
              Relationships between Sets of Label Switched Paths
              (LSPs)", RFC 8697, DOI 10.17487/RFC8697, January 2020,
              <https://www.rfc-editor.org/info/rfc8697>.

   [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>.

   [RFC8821]  Wang, A., Khasanov, B., Zhao, Q., and H. Chen, "PCE-Based
              Traffic Engineering (TE) in Native IP Networks", RFC 8821,
              DOI 10.17487/RFC8821, April 2021,
              <https://www.rfc-editor.org/info/rfc8821>.

Authors' Addresses
   Aijun Wang
   China Telecom
   Beiqijia Town, Changping District
   Beijing,
   Beijing
   Beijing, 102209
   China

   Email: wangaj3@chinatelecom.cn

   Boris Khasanov
   Yandex LLC
   Ulitsa Lva Tolstogo 16
   Moscow
   Russia

   Email: 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
   Nanjing
   Jiangsu, 210012
   China

   Email: zhu.chun1@zte.com.cn