PCEP Procedures and Extension for VLAN-based Traffic Forwarding
draft-wang-pce-vlan-based-traffic-forwarding-00

Document Type Active Internet-Draft (individual)
Authors Wang Yue  , Aijun Wang 
Last updated 2021-05-17
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PCE Working Group                                                Y. Wang
Internet-Draft                                                   A. Wang
Intended status: Standards Track                           China Telecom
Expires: November 19, 2021                                  May 18, 2021

    PCEP Procedures and Extension for VLAN-based Traffic Forwarding
            draft-wang-pce-vlan-based-traffic-forwarding-00

Abstract

   This document defines the Path Computation Element Communication
   Protocol (PCEP) extension for VLAN-based traffic forwarding in native
   IP network and describes the essential elements and key processes of
   the data packet forwarding system based on VLAN info to accomplish
   the End to End (E2E) traffic assurance for VLAN-based traffic
   forwarding in native IP network.

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
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   This Internet-Draft will expire on November 19, 2021.

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   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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   include Simplified BSD License text as described in Section 4.e of

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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Conventions used in this document . . . . . . . . . . . . . .   3
   3.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Procedures for VLAN-based Traffic Forwarding  . . . . . . . .   3
   5.  Capability Advertisement  . . . . . . . . . . . . . . . . . .   4
   6.  PCEP message  . . . . . . . . . . . . . . . . . . . . . . . .   4
     6.1.  The PCInitiate message  . . . . . . . . . . . . . . . . .   5
     6.2.  The PCRpt message . . . . . . . . . . . . . . . . . . . .   6
   7.  VXLAN-based traffic forwarding Procedures . . . . . . . . . .   7
     7.1.  Multiple BGP Session Establishment Procedures . . . . . .   7
     7.2.  BGP Prefix Advertisement Procedures . . . . . . . . . . .   8
     7.3.  VLAN mapping info Advertisement Procedures  . . . . . . .   9
       7.3.1.  VLAN-Based forwarding info Advertisement Procedures .   9
       7.3.2.  VLAN-Based crossing info Advertisement Procedures . .  10
   8.  New PCEP Objects  . . . . . . . . . . . . . . . . . . . . . .  12
     8.1.  VLAN forwarding CCI Object  . . . . . . . . . . . . . . .  12
     8.2.  Peer IP Address TLVs  . . . . . . . . . . . . . . . . . .  13
     8.3.  VLAN crossing CCI Object  . . . . . . . . . . . . . . . .  14
   9.  Deployment Considerations . . . . . . . . . . . . . . . . . .  15
   10. Security Considerations . . . . . . . . . . . . . . . . . . .  15
   11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
     11.1.  Path Setup Type Registry . . . . . . . . . . . . . . . .  15
     11.2.  PCECC-CAPABILITY sub-TLV's Flag field  . . . . . . . . .  15
     11.3.  PCEP Object Types  . . . . . . . . . . . . . . . . . . .  15
     11.4.  PCEP-Error Object  . . . . . . . . . . . . . . . . . . .  15
   12. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  16
   13. Normative References  . . . . . . . . . . . . . . . . . . . .  16
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  17

1.  Introduction

   Based on the PCEP, a southbound interface protocol of the controller,
   the PCE can calculate the optimal path for various applications and
   sends it to the network equipment through the centralized path
   calculation mechanism, so as to control the packet forwarding and
   make the separation of path calculation and establishment function.

   With the large scale deployment of Ethernet interface, it is possible
   to use the info contained in the Layer2 message to simplify the
   processing of a distributed control plane.  This document defines a
   Path Computation Element Communication Protocol (PCEP) Extension for
   VLAN-based traffic forwarding by using the VLAN info contained in the
   Ethernet frame in native IP network.  It is an end to end traffic

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   guarantee mechanism based on the PCEP protocol in the native IP
   environment, which can ensure the connection-oriented network
   communication.  It can simplifiy the calculation and forwarding
   process of the optimal path by blending it with elements of PCEP and
   without necessarily completely replacing it.  Compared with other
   traffic assurance technologies such as mpls or srv6, the VLAN-based
   traffic forwarding mechanism uses a completely new address space
   which will not conflict with other existing protocols.  It is
   suitable for ipv4 and ipv6 networks and can leverage the existing PCE
   technologies as much as possible.

2.  Conventions used in this document

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

3.  Terminology

   The following terms are defined in this draft:

   o  PCC: Path Computation Client

   o  PCE: Path Computation Element

   o  PCEP: PCE Communication Protocol

   o  PCECC: PCE-based Central Controller

   o  LSP: Lable Switching Path

   o  PST: Path Setup Type

4.  Procedures for VLAN-based Traffic Forwarding

   In order to set up the VLAN-based traffic forwarding paths for
   different applications in native IP network, multiple BGP sessions
   should be deployed between the ingress PCC and egress PCC at the edge
   of the network respectively.  Based on the business requirements, the
   PCE calculates the explict route and sends the route information to
   the PCCs through PCInitiate messages.  When received the PCInitiate
   message, the ingress PCC will form a VLAN-Forwarding routing table
   defined in this document.  The packet to be guaranteed will be
   matched in the table and then be labeled with corresponding VLAN tag.
   The labeled packet will be further sent to the PCC's specific
   subinterface identified by the VLAN tag and then be forwarded.
   Similarly, the transit PCC and the egress PCC will form a VLAN-
   Crossing routing table after received the PCInitiate message.  The

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   packet to be guaranteed will be relabled with new VLAN tag and then
   be forwarded.

5.  Capability Advertisement

   During the PCEP Initialization Phase, PCEP Speakers (PCE or PCC)
   advertise their support of VLAN-based trafficforwarding extensions.
   This document defines a new Path Setup Type (PST)[RFC8408] for PCECC,
   as follows:

   o  PST=TBD1: Path is a VLAN-based traffic forwarding type.

   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.

   Because the path is set up through PCE, a PCEP speaker must advertise
   the PCECC capability by using PCECC-CAPABILITY sub-TLV which is used
   to exchange information about their PCECC capability as per PCEP
   extensions defined in
   [I-D.ietf-pce-pcep-extension-for-pce-controller]

   A new flag is defined in PCECC-CAPABILITY sub-TLV for VLAN-based
   traffic forwarding.

   V (VLAN-based-forwarding-CAPABILITY - 1 bit - TBD2): If set to 1 by a
   PCEP speaker, it indicates that the PCEP speaker supports the
   capability of VLAN based traffic forwarding 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 V 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 VLAN-based-forwarding-
      CAPABILITY bit is not set).

   o  Terminate the PCEP session

6.  PCEP message

   As per [RFC8281] ,the PCInitiate message sent by a PCE was defined to
   trigger LSP instantiation or deletion with the SRP and LSP object
   included during the PCEP initialization phase.  The Path Computation
   LSP State Report message (PCRpt message) was defined in [RFC8231],
   which is used to report the current state of a LSP.  A PCC can send a

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   LSP State Report message in response to a LSP instantiation.
   Besides, the message can either in response to a LSP Update Request
   from a PCE or asynchronously when the state of a LSP changes .

   [I-D.ietf-pce-pcep-extension-for-pce-controller] defines an object
   called Central Controller Instructions (CCI) to specify the
   forwarding instructions to the PCC.  During the coding process used
   for central controller instructions, the object contains the label
   information and is carried within PCInitiate or PCRpt message for
   label download .

   This document specify two new CCI object-types for VLAN-based traffic
   forwarding in the native IP network and are said to be mandatory in a
   PCEP message when the object must be included for the message to be
   considered valid.  In addition, this document enxtends the PCEP
   message to handle the VLAN-based traffic forwarding path in the
   native IP network with the new CCI object.

6.1.  The PCInitiate message

   The PCInitiate message[RFC8281] extended
   in[I-D.ietf-pce-pcep-extension-for-pce-controller] can be used to
   download or remove labels by using the CCI Object.

   Based on the extended PCInitiate message and PCRpt described in
   [I-D.ietf-pce-pcep-extension-native-ip], the (BGP Peer Info (BPI)
   Object and the Peer Prefix Association (PPA) Object is used to
   establish multi BGP sessions and advertise route prefixes among
   different BGP sessions before setting up a VLAN-based traffic
   forwarding path.

   This document extends the PCInitiate message as shown below:

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     <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>|<PPA>)
                                                   <new-CCI>)

           <cci-list> ::=  <new-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].
            <BPI> and <PPA> are as per
            [draft-ietf-pce-pcep-extension-native-ip-09]

   When PCInitiate message is used to create VLAN-based forwarding
   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, PPA or one type of CCI objects 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 ( VLAN-
   based forwarding object missing).  If there are more than one of BPI,
   PPA or one type of CCI objects are presented, the receiving PCC MUST
   send a PCErr message with Error-type=19(Invalid Operation) and Error-
   value=TBD5(Only one of BPI, PPA or one type of the CCI objects for
   VLAN can be included in this message).

6.2.  The PCRpt message

   The PCRpt message is used to report the state and confirm the VLAN
   info that were allocated by the PCE, to be used during the state
   synchronization phase or as acknowledgemnt to PCInitiate message.

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   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>|<PPA>)
                                         (<new-CCI>)

          Where:
            <path> is as per [RFC8231] and the LSP and SRP object are
            also defined in [RFC8231].
            <BPI> and <PPA> are as per
            [draft-ietf-pce-pcep-extension-native-ip-09]

   The error handling for missing LSP or CCI object is as per
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Further only one
   of BPI, PPA or one type of CCI objects 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 ( VLAN-
   based forwarding object missing).  If there are more than one of BPI,
   PPA or one type of CCI objects are presented, the receiving PCC MUST
   send a PCErr message with Error-type=19(Invalid Operation) and Error-
   value=TBD5(Only one of BPI, PPA or one type of the CCI objects for
   VLAN can be included in this message).

7.  VXLAN-based traffic forwarding Procedures

7.1.  Multiple BGP Session Establishment Procedures

   As described in section 4, multiple BGP sessions should be deployed
   between the ingress device and egress device at the edge of the
   network respectively in order to carry informations of different
   applications.  As per [I-D.ietf-pce-pcep-extension-native-ip], the
   PCE should send the BPI((BGP Peer Info) Object to the ingress and

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   egress device with the indicated Peer AS and Local/Peer IP address.
   The Ingress and egress devices will receive multiple BPI objects to
   establish sessions with different next hop.  The specific process is
   as follows:

               +----------------------+
     +---------+-        PCE          + --------+
     |         +----------^-----------+         |
     |          |         |          |          |
     |        +--+       +--+       +--+        |
     |------- +R2+ ------+R3+-------+R4+ --------
     |        +--+       +--+       +--+        |
     |                                          |
     +--+                +--+                +--+
     +R1+----------------+R5+----------------+R6+
     +--+                +--+                +--+
     |                                          |
     |<------------- BGP Session A ------------>|
     |<------------- BGP Session B ------------>|
     |<------------- BGP Session C ------------>|

    Figure 1: BGP Session Establishment Procedures

7.2.  BGP Prefix Advertisement Procedures

   The detail procedures for BGP prefix advertisement procedures is
   introduced in [I-D.ietf-pce-pcep-extension-native-ip], using
   PCInitiate and PCRpt message pair.

   The BGP prefix for different BGP sessions should be sent to the
   ingress and egress device respectively.  The end-to-end traffic for
   key application can be identified based on these BGP prefix
   informations and be further assured.  As per
   [I-D.ietf-pce-pcep-extension-native-ip], the PPA(Peer Prefix
   Association) object with list of prefix subobjects and the peer
   address will be sent through the PCInitiate and PCRpt message
   pair.The specific process is as follows,:

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               +----------------------+
     +---------+-        PCE          + --------+
     |         +----------^-----------+         |
     |          |         |          |          |
     |        +--+       +--+       +--+        |
     |------- +R2+ ------+R3+-------+R4+ --------
     |        +--+       +--+       +--+        |
     |                                          |
     +--+                +--+                +--+
     +R1+----------------+R5+----------------+R6+
     +--+                +--+                +--+
      Figure 2: BGP Prefix Advertisement Procedures

   Through BGP protocol, the ingress device can learn different BGP
   prefix of the egress device based on the different BGP sessions.

7.3.  VLAN mapping info Advertisement Procedures

   After the BGP prefix for different BGP session are successfully
   advertised, informations of different applications should be
   forwarded to different VLAN-based traffic forwarding paths.  In order
   to set up a VLAN-based traffic forwarding path, the PCE should send
   the VLAN forwarding CCI Object with the VLAN-ID included to the
   ingress PCC and the VLAN crossing CCI Object to the transit PCC and
   egrss PCC.

7.3.1.  VLAN-Based forwarding info Advertisement Procedures

   The detail procedures for VLAN-Based forwarding info advertisement
   contained in the VLAN forwarding CCI Object is shown below, using
   PCInitiate and PCRpt message pair.

   The VLAN forwarding CCI Object should be sent through the PCInitiate
   and PCRpt message pair.  After the PCC receives the CCI object (with
   the R bit set to 0 in SRP object) in PCInitiate message, the PCC will
   form a VLAN-Forwarding routing table based on the VLAN forwarding CCI
   object, source and destination BGP prefix learnt before.  When the
   ingress PCC receives a packet, it will look up the VLAN-Forwarding
   routing table based on the source and destination IP contained in the
   packet.  The packet to be guaranteed will be matched in the table and
   then be labeled with corresponding VLAN tag.  After that, The labeled
   packet will be further forwarded to the specific subinterface.

   When the packet is tagged and successfully sent, the PCC should
   report the result via the PCRpt messages, with VLAN forwarding CCI
   Object and the corresponding SRP object included.

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   When PCC receives the VLAN forwarding CCI Object with the R bit set
   to 1 in SRP object in PCInitiate message, the PCC should withdraw the
   VLAN-Based forwarding info advertisement to the peer that indicated
   by this object.

   When PCC withdraws the VLAN-Based forwarding info that indicated by
   this object successfully, it should report the result via the PCRpt
   message, with the corresponding SRP and CCI object included.

               +----------------------+
     +---------+         PCE          + --------+
     |         +----------^-----------+         |
     |          |         |          |          |
    M1&M1-R     |         |          |          |
     |          |         |          |          |
     |          |         |          |          |
     |        +--+       +--+       +--+        |
     |------- +R2+ ------+R3+-------+R4+ --------
     |        +--+       +--+       +--+        |
     |                                          |
     +--+                +--+                +--+
     +R1+----------------+R5+----------------+R6+
     +--+                +--+                +--+
   Figure 3: VLAN-Based forwarding info Advertisement
                 Procedures for Ingress PCC

   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                            |
   |M1-R|      |PCRpt     |VLAN Forwarding CCI Object          |
   |    |      |          |(Peer_IP=R6_A,VLAN_ID=VLAN_R1_R2)   |
   +-----------------------------------------------------------+

7.3.2.  VLAN-Based crossing info Advertisement Procedures

   The detail procedures for VLAN-Based crossing info advertisement
   contained in the VLAN crossing CCI Object is shown below, using
   PCInitiate and PCRpt message pair.

   After the process of VLAN-Based forwarding info advertisement
   mentioned above, the PCC will form a VLAN-crossing routing table
   based on the VLAN crossing CCI Object(with the R bit set to 0 in SRP
   object) contained in the PCInitiate message.  The VLAN-crossing

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   routing table consists of an in-VLAN tag and an out-VLAN tag which
   specifies a new VLAN forwarding path.  When the transit PCC receives
   a data packet that has been labeled with VLAN by ingress PCC before,
   it will look up the VLAN-Crossing routing table based on the VLAN
   tag.  If matched, the in-VLAN tag will be replaced by a new out-VLAN
   tag according to the table.The packet with the new VLAN tag will be
   further forwarded to the next hop.

   For the egress PCC, the out-VLAN tag in the VLAN-crossing routing
   table should be 0 which indicates it is the last hop of the
   transmission.  So the egress PCC will directly remove the in-VLAN tag
   of the packet and the packet will be forwarded.

   When the packet is tagged and successfully sent to the specific
   subinterface, the PCC should report the result via the PCRpt
   messages, with the corresponding SRP and CCI object included.

   When PCC receives the VLAN crossing CCI Object with the R bit set to
   1 in SRP object in PCInitiate message, the PCC should withdraw the
   VLAN-Based crossing info advertisement to the peer that indicated by
   this object.

   When PCC withdraws the VLAN-Based crossing info that indicated by
   this object successfully, it should report the result via the PCRpt
   message, with the corresponding SRP and CCI object included.

   When the out-VLAN tag conflicts with a pre-defined VLAN tag or the
   PCC can not set up a VLAN forwarding path with the out-VLAN tag, an
   error (Error-type=TBD6, VLAN-based forwarding failure, Error-
   value=TBD7, VLAN crossing CCI Object peer info mismatch) should be
   reported via the PCRpt message.

                   +----------------------+
         +---------+         PCE          + --------+
         |         +----------^-----------+         |
         |          |         |          |          |
         |       M1&M1-R   M2&M2-R    M3&M3-R    M4&M4-R
         |          |         |          |          |
         |          |         |          |          |
         |        +--+       +--+       +--+        |
         |------- +R2+ ------+R3+-------+R4+ -------|
         |        +--+       +--+       +--+        |
         |                                          |
         +--+                +--+                +--+
         +R1+----------------+R5+----------------+R6+
         +--+                +--+                +--+
   Figure 4: VLAN-Based crossing info Advertisement Procedures
                   for transit PCC and egress PCC

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   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/R2|PCInitiate|CC-ID=X1                                       |
|M1-R|      |PCRpt     |VLAN crossing CCI Object                       |
|    |      |          |(IN_VLAN_ID=VLAN_R1_R2,OUT_VLAN_ID=VLAN_R2_R3) |
+----------------------------------------------------------------------+
|M2  |PCE/R3|PCInitiate|CC-ID=X1                                       |
|M2-R|      |PCRpt     |VLAN crossing CCI Object                       |
|    |      |          |(IN_VLAN_ID=VLAN_R2_R3,OUT_VLAN_ID=VLAN_R3_R4) |
+----------------------------------------------------------------------+
|M3  |PCE/R4|PCInitiate|CC-ID=X1                                       |
|M3-R|      |PCRpt     |VLAN crossing CCI Object                       |
|    |      |          |(IN_VLAN_ID=VLAN_R3_R4,OUT_VLAN_ID=VLAN_R4_R6) |
+----------------------------------------------------------------------+
|M4  |PCE/R6|PCInitiate|CC-ID=X1                                       |
|M4-R|      |PCRpt     |VLAN crossing CCI Object                       |
|    |      |          |(IN_VLAN_ID=VLAN_R4_R6,OUT_VLAN_ID=0)          |
+----------------------------------------------------------------------+

8.  New PCEP Objects

   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 two CCI object-types for VLAN-based traffic
   forwarding network.  All new PCEP objects are compliant with the PCEP
   object format defined in [RFC5440].

8.1.  VLAN forwarding CCI Object

   The VLAN forwarding CCI Object is used to set up the specific vlan
   forwarding path of the logical subinterface that the traffic will be
   forwarded to and transfer the packet to the specific hop.  Combined
   with this type of CCI Object and the Peer Prefix Association
   object(PPA) defined in [I-D.ietf-pce-pcep-extension-native-ip], the
   ingress PCC will form a VLAN-Forwarding routing table which is used
   to identify the traffic that needs to be protected.  This object
   should only be included and sent to the ingress PCC of the end2end
   path.

   CCI Object-Class is 44.

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   CCI Object-Type is TBD8 for VLAN forwarding info in the native IP
   network.

       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                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            Reserved1           |            Flags             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          VLAN-ID       |                 Reserved2            |
      +---------------------------------------------------------------+
      |                                                               |
      //                      Peer IP address TLV                     //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                      Figure 5: VLAN forwarding CCI Object

   The fields in the CCI object are as follows:

   CC-ID: is as described in
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Following fields
   are defined for CCI Object-Type TBD8.

   Reserved1(16 bits): is set to zero while sending, ignored on receipt.

   Flags(16 bits): is used to carry any additional information
   pertaining to the CCI.  Currently no flag bits are defined.

   VLAN ID(12 bits):the ID of the VLAN forwarding path that the PCC will
   set up on its logical subinterface in order to transfer the packet to
   the specific hop.

   Reserved2(20 bits): is set to zero while sending, ignored on receipt.

   The Peer IP Address TLV[RFC8231]MUST be included in this CCI Object-
   Type TBD8 to identify the end to end TE path in VLAN-based traffic
   forwarding network and MUST be unique.

8.2.  Peer IP Address TLVs

   [RFC8779] defines IPV4-ADDRESS, IPV6-ADDRESS, and UNNUMBERED-ENDPOINT
   TLVs for the use of Generalized Endpoint.  The same TLVs can also be
   used in the CCI object to find the Peer address that matches egress
   PCC and further identify the packet to be guaranteed.  If the PCC is
   not able to resolve the peer information or can not find the
   corresponding ingress device, it MUST reject the CCI and respond with

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   a PCErr message with Error-Type = TBD6 ("VLAN-based forwarding
   failure") and Error Value = TBD9 ("Invalid egress PCC information").

8.3.  VLAN crossing CCI Object

   The VLAN crossing CCI object is defined to control the transmission-
   path of the packet by VLAN-ID.This new type of CCI Object can be
   carried within a PCInitiate message sent by the PCE to the transit
   PCC and the egress PCC in the VLAN-based traffic forwarding
   scenarios.

   CCI Object-Class is 44.

   CCI Object-Type is TBD10 for VLAN crossing info in the native IP
   network.

       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                              |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |            Reserved1           |            Flags             |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       IN-VLAN-ID     |     OUT-VLAN-ID     |     Reserved2    |
      +---------------------------------------------------------------+
      |                                                               |
      //                        Additional TLVs                       //
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 6:  VLAN Crossing CCI Object

   CC-ID: is as described in
   [I-D.ietf-pce-pcep-extension-for-pce-controller].  Following fields
   are defined for CCI Object-Type TBD10.

   Reserved1(16 bits): is set to zero while sending, ignored on receipt.

   Flags(16 bits): is used to carry any additional information
   pertaining to the CCI.  Currently no flag bits are defined.

   IN-VLAN ID(12 bits): The ID of the VLAN forwarding path which is used
   to identify the traffic that needs to be protected.

   OUT-VLAN ID(12 bits):The ID of the VLAN forwarding path that the PCC
   will set up on its logical subinterface in order to transfer the
   packet labeld with this VLAN ID to the specific hop.To the transit
   PCC, the value must not be 0 to indicate it is not the last hop of

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   the VLAN-based traffic forwarding path.  To the egress PCC, the value
   must be 0 to indicate it is the last hop of the VLAN-based traffic
   forwarding path.

   Reserved2(8 bits): is set to zero while sending, ignored on receipt.

9.  Deployment Considerations

10.  Security Considerations

11.  IANA Considerations

11.1.  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         VLAN-Based Traffic Forwarding Path       This document

11.2.  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(V)            VLAN-Based  Forwarding CAPABILITY       This document

11.3.  PCEP Object Types

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

Object-Class Value      Name                                 Reference
44                      CCI Object-Type                      This document
                        TBD8: VLAN forwarding CCI
                        TBD10: VLAN crossing CCI

11.4.  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:

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Error-Type  Meaning                   Error-value            Reference
6           Mandatory Object missing  TBD4:VLAN-based        This document
                                      forwarding object
                                      missing
10          Reception of an          TBD3:PCECC              This document
            invalid object           VLAN-based-forwarding
                                     -CAPABILITY
                                     bit is not set
19          Invalid Operation        TBD5: Only one of BPI,  This document
                                     PPA or one type of
                                     the CCI objects
                                     for VLAN can be included
                                     in this message
TBD6        VLAN-based forwarding    TBD7: VLAN crossing CCI This document
            failure                  Object peer info mismatch
                                     TBD9: Invalid egress   This document
                                     PCC information

12.  Acknowledgement

13.  Normative References

   [I-D.ietf-pce-pcep-extension-for-pce-controller]
              Li, Z., Peng, S., Negi, M. S., 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-14 (work in progress),
              March 2021.

   [I-D.ietf-pce-pcep-extension-native-ip]
              Wang, A., Khasanov, B., Fang, S., Tan, R., and C. Zhu,
              "PCEP Extension for Native IP Network", draft-ietf-pce-
              pcep-extension-native-ip-13 (work in progress), March
              2021.

   [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>.

   [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>.

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   [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>.

   [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>.

   [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>.

   [RFC8779]  Margaria, C., Ed., Gonzalez de Dios, O., Ed., and F.
              Zhang, Ed., "Path Computation Element Communication
              Protocol (PCEP) Extensions for GMPLS", RFC 8779,
              DOI 10.17487/RFC8779, July 2020,
              <https://www.rfc-editor.org/info/rfc8779>.

Authors' Addresses

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

   Email: wangy73@chinatelecom.cn

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

   Email: wangaj3@chinatelecom.cn

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