[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-li-pce-pcep-flowspec) 00 01 02

Network Working Group                                      D. Dhody, Ed.
Internet-Draft                                       Huawei Technologies
Intended status: Standards Track                          A. Farrel, Ed.
Expires: April 19, 2019                                 Juniper Networks
                                                                   Z. Li
                                                     Huawei Technologies
                                                        October 16, 2018


                 PCEP Extension for Flow Specification
                    draft-ietf-pce-pcep-flowspec-02

Abstract

   The Path Computation Element (PCE) is a functional component capable
   of selecting the paths through a traffic engineered network.  These
   paths may be supplied in response to requests for computation, or may
   be unsolicited instructions issued by the PCE to network elements.
   Both approaches use the PCE Communication Protocol (PCEP) to convey
   the details of the computed path.

   Traffic flows may be categorized and described using "Flow
   Specifications".  RFC 5575 defines the Flow Specification and
   describes how it may be distributed in BGP to allow specific traffic
   flows to be associated with routes.

   This document specifies a set of extensions to PCEP to support
   dissemination of Flow Specifications.  This allows a PCE to indicate
   what traffic should be placed on each path that it is aware of.

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 April 19, 2019.





Dhody, et al.            Expires April 19, 2019                 [Page 1]


Internet-Draft                PCEP-FlowSpec                 October 2018


Copyright Notice

   Copyright (c) 2018 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Procedures for PCE Use of Flow Specifications . . . . . . . .   4
     3.1.  Capability Advertisement  . . . . . . . . . . . . . . . .   5
       3.1.1.  PCEP OPEN Message . . . . . . . . . . . . . . . . . .   5
       3.1.2.  IGP PCE Capabilities Advertisement  . . . . . . . . .   5
     3.2.  Dissemination Procedures  . . . . . . . . . . . . . . . .   6
     3.3.  Flow Specification Synchronization  . . . . . . . . . . .   7
   4.  PCE FlowSpec Capability TLV . . . . . . . . . . . . . . . . .   7
   5.  PCEP FLOWSPEC Object  . . . . . . . . . . . . . . . . . . . .   8
   6.  Flow Filter TLV . . . . . . . . . . . . . . . . . . . . . . .  10
   7.  Flow Specification TLVs . . . . . . . . . . . . . . . . . . .  10
   8.  Detailed Procedures . . . . . . . . . . . . . . . . . . . . .  13
     8.1.  Default Behavior and Backward Compatibility . . . . . . .  13
     8.2.  Composite Flow Specifications . . . . . . . . . . . . . .  13
     8.3.  Modifying Flow Specifications . . . . . . . . . . . . . .  14
     8.4.  Multiple Flow Specifications  . . . . . . . . . . . . . .  14
     8.5.  Adding and Removing Flow Specifications . . . . . . . . .  14
     8.6.  VPN Identifiers . . . . . . . . . . . . . . . . . . . . .  15
     8.7.  Priorities and Overlapping Flow Specifications  . . . . .  15
   9.  PCEP Messages . . . . . . . . . . . . . . . . . . . . . . . .  15
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  18
     10.1.  PCEP Objects . . . . . . . . . . . . . . . . . . . . . .  18
       10.1.1.  PCEP FLOWSPEC Object Flag Field  . . . . . . . . . .  18
     10.2.  PCEP TLV Type Indicators . . . . . . . . . . . . . . . .  19
     10.3.  Flow Specification TLV Type Indicators . . . . . . . . .  19
     10.4.  PCEP Error Codes . . . . . . . . . . . . . . . . . . . .  20
     10.5.  PCE Capability Flag  . . . . . . . . . . . . . . . . . .  21
   11. Security Considerations . . . . . . . . . . . . . . . . . . .  21
   12. Manageability Considerations  . . . . . . . . . . . . . . . .  22
   13. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  22



Dhody, et al.            Expires April 19, 2019                 [Page 2]


Internet-Draft                PCEP-FlowSpec                 October 2018


   14. References  . . . . . . . . . . . . . . . . . . . . . . . . .  22
     14.1.  Normative References . . . . . . . . . . . . . . . . . .  22
     14.2.  Informative References . . . . . . . . . . . . . . . . .  23
   Appendix A.  Flow Specification TLV Types . . . . . . . . . . . .  25
   Appendix B.  Contributors . . . . . . . . . . . . . . . . . . . .  27
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  28

1.  Introduction

   [RFC4655] defines the Path Computation Element (PCE), a functional
   component capable of computing paths for use in traffic engineering
   networks.  PCE was originally conceived for use in Multiprotocol
   Label Switching (MPLS) for Traffic Engineering (TE) networks to
   derive the routes of Label Switched Paths (LSPs).  However, the scope
   of PCE was quickly extended to make it applicable to Generalized MPLS
   (GMPLS) networks, and more recent work has brought other traffic
   engineering technologies and planning applications into scope (for
   example, Segment Routing (SR) [I-D.ietf-pce-segment-routing]).

   [RFC5440] describes the Path Computation Element Communication
   Protocol (PCEP).  PCEP defines the communication between a Path
   Computation Client (PCC) and a PCE, or between PCE and PCE, enabling
   computation of path for MPLS-TE LSPs.

   Stateful PCE [RFC8231] specifies a set of extensions to PCEP to
   enable control of TE-LSPs by a PCE that retains state about the the
   LSPs provisioned in the network (a stateful PCE).  [RFC8281]
   describes the setup, maintenance, and teardown of LSPs initiated by a
   stateful PCE without the need for local configuration on the PCC,
   thus allowing for a dynamic network that is centrally controlled.
   [RFC8283] introduces the architecture for PCE as a central controller
   and describes how PCE can be viewed as a component that performs
   computation to place 'flows' within the network and decide how these
   flows are routed.

   Dissemination of traffic flow specifications (Flow Specifications)
   was introduced for BGP in [RFC5575].  A Flow Specification is
   comprised of traffic filtering rules and actions.  The routers that
   receive a Flow Specification can classify received packets according
   to the traffic filtering rules and can direct packets based on the
   actions.

   When a PCE is used to initiate tunnels (such as TE-LSPs or SR paths)
   using PCEP, it is important that the head end of the tunnels
   understands what traffic to place on each tunnel.  The data flows
   intended for a tunnel can be described using Flow Specifications, and
   when PCEP is in use for tunnel initiation it makes sense for that




Dhody, et al.            Expires April 19, 2019                 [Page 3]


Internet-Draft                PCEP-FlowSpec                 October 2018


   same protocol to be used to distribute the Flow Specifications that
   describe what data is to flow on those tunnels.

   This document specifies a set of extensions to PCEP to support
   dissemination of Flow Specifications.  The extensions include the
   creation, update, and withdrawal of Flow Specifications via PCEP, and
   can be applied to tunnels initiated by the PCE or to tunnels where
   control is delegated to the PCE by the PCC.  Furthermore, a PCC
   requesting a new path can include Flow Specifications in the request
   to indicate the purpose of the tunnel allowing the PCE to factor this
   in during the path computation.

   Flow Specifications are carried in TLVs within a new Flow Spec Object
   defined in this document.  The flow filtering rules indicated by the
   Flow Specifications are mainly defined by BGP Flow Specifications.

2.  Terminology

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

   The following term from [RFC5575] is used frequently throughout this
   document:

      Flow Specification (FlowSpec): A Flow Specification is an n-tuple
      consisting of several matching criteria that can be applied to IP
      traffic, including filters and actions.  Each FlowSpec consists of
      a set of filters and a set of actions.

   This document uses the terms "stateful PCE" and "active PCE" as
   advocated in [RFC7399].

   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.  Procedures for PCE Use of Flow Specifications

   There are three elements of procedure:

   o  A PCE and a PCC must be able to indicate whether or not they
      support the use of Flow Specifications.

   o  A PCE or PCC must be able to include Flow Specifications in PCEP
      messages with clear understanding of the applicability of those
      Flow Specifications in each case including whether the use of such



Dhody, et al.            Expires April 19, 2019                 [Page 4]


Internet-Draft                PCEP-FlowSpec                 October 2018


      information is mandatory, constrained, or optional, and how
      overlapping Flow Specifications will be resolved.

   o  Flow Specification information/state must be synchronized between
      PCEP peers so that, on recovery, the peers have the same
      understanding of which Flow Specifications apply.

   The following subsections describe these points.

3.1.  Capability Advertisement

   As with most PCEP capability advertisements, the ability to support
   Flow Specifications can be indicated in the PCEP OPEN message or in
   IGP PCE capability advertisements.

3.1.1.  PCEP OPEN Message

   During PCEP session establishment, a PCC or PCE that supports the
   procedures described in this document announces this fact by
   including the "PCE FlowSpec Capability" TLV (described in Section 4)
   in the OPEN Object carried in the PCEP Open message.

   The presence of the PCE FlowSpec Capability TLV in the OPEN Object in
   a PCE's OPEN message indicates that the PCE can distribute FlowSpecs
   to PCCs and can receive FlowSpecs in messages from the PCCs.

   The presence of the PCE FlowSpec Capability TLV in the OPEN Object in
   a PCC's OPEN message indicates that the PCC supports the FlowSpec
   functionality described in this document.

   If either one of a pair of PCEP peers does not indicate support of
   the functionality described in this document by not including the PCE
   FlowSpec Capability TLV in the OPEN Object in its OPEN message, then
   the other peer MUST NOT include a FlowSpec object in any PCEP message
   sent to the peer that does not support the procedures.  If a FlowSpec
   object is received even though support has not been indicated, the
   receiver will respond with a PCErr message reporting the objects
   containing the FlowSpec as described in [RFC5440]: that is, it will
   use 'Unknown Object' if it does not support this specification, and
   'Not supported object' if it supports this specification but has not
   chosen to support FlowSpec objects on this PCEP session.

3.1.2.  IGP PCE Capabilities Advertisement

   The ability to advertise support for PCEP and PCE features in IGP
   advertisements is provided for OSPF in [RFC5088] and for IS-IS in
   [RFC5089].  The mechanism uses the PCE Discovery TLV which has a PCE-




Dhody, et al.            Expires April 19, 2019                 [Page 5]


Internet-Draft                PCEP-FlowSpec                 October 2018


   CAP-FLAGS sub-TLV containing bit-flags each of which indicates
   support for a different feature.

   This document defines a new PCE-CAP-FLAGS sub-TLV bit, the FlowSpec
   Capable flag (bit number TBD1).  Setting the bit indicates that an
   advertising PCE supports the procedures defined in this document.

   Note that while PCE FlowSpec Capability may be advertised during
   discovery, PCEP speakers that wish to use Flow Specification in PCEP
   MUST negotiate PCE FlowSpec Capability during PCEP session setup, as
   specified in Section 3.1.1.  A PCC MAY initiate PCE FlowSpec
   Capability negotiation at PCEP session setup even if it did not
   receive any IGP PCE capability advertisement, and a PCEP peer that
   advertised support for FlowSpec in the IGP is not obliged to support
   these procedures on any given PCEP session.

3.2.  Dissemination Procedures

   This section describes the procedures to support Flow Specifications
   in PCEP messages.

   The primary purpose of distributing Flow Specification information is
   to allow a PCE to indicate to a PCC what traffic it should place on a
   path (such as an LSP or an SR path).  This means that the Flow
   Specification may be included in:

   o  PCInitiate messages so that an active PCE can indicate the traffic
      to place on a path at the time that the PCE instantiates the path.

   o  PCUpd messages so that an active PCE can indicate or change the
      traffic to place on a path that has already been set up.

   o  PCRpt messages so that a PCC can report the traffic that the PCC
      plans to place on the path.

   o  PCReq messages so that a PCC can indicate what traffic it plans to
      place on a path at the time it requests the PCE to perform a
      computation in case that information aids the PCE in its work.

   o  PCRep messages so that a PCE that has been asked to compute a path
      can suggest which traffic could be placed on a path that a PCC may
      be about to set up.

   o  PCErr messages so that issues related to paths and the traffic
      they carry can be reported to the PCE by the PCC, and so that
      problems with other PCEP messages that carry Flow Specifications
      can be reported.




Dhody, et al.            Expires April 19, 2019                 [Page 6]


Internet-Draft                PCEP-FlowSpec                 October 2018


   To carry Flow Specifications in PCEP messages, this document defines
   a new PCEP object called the PCEP FLOWSPEC Object.  The object is
   OPTIONAL in the messages described above and MAY appear more than
   once in each message.

   The PCEP FLOWSPEC Object carries zero or one Flow Filter TLV which
   describes a traffic flow.

   The inclusion of multiple PCEP FLOWSPEC Objects allows multiple
   traffic flows to be placed on a single path.

   Once a PCE and PCC have established that they can both support the
   use of Flow Specifications in PCEP messages, such information may be
   exchanged at any time for new or existing paths.

   The application and prioritization of Flow Specifications is
   described in Section 8.7.

3.3.  Flow Specification Synchronization

   The Flow Specifications are carried along with the LSP State
   information as per [RFC8231] making the Flow Specifications part of
   the LSP database (LSP-DB).  Thus, the synchronization of the Flow
   Specification information is done as part of LSP-DB synchronization.
   This may be achieved using normal state synchronization procedures as
   described in [RFC8231] or enhanced state synchronization procedures
   as defined in [RFC8232].

   The approach selected will be implementation and deployment specific
   and will depend on issues such as how the databases are constructed
   and what level of synchronization support is needed.

4.  PCE FlowSpec Capability TLV

   The PCE-FLOWSPEC-CAPABILITY TLV is an optional TLV that can be
   carried in the OPEN Object [RFC5440] to exchange PCE FlowSpec
   capabilities of PCEP speakers.

   The format of the PCE-FLOWSPEC-CAPABILITY TLV follows the format of
   all PCEP TLVs as defined in [RFC5440] and is shown in Figure 1.











Dhody, et al.            Expires April 19, 2019                 [Page 7]


Internet-Draft                PCEP-FlowSpec                 October 2018


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Type=TBD2             |          Length=2             |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Value=0             |          Padding              |
   +---------------------------------------------------------------+


               Figure 1: PCE-FLOWSPEC-CAPABILITY TLV format

   The type of the PCE-FLOWSPEC-CAPABILITY TLV is TBD2 and it has a
   fixed length of 2 octets.  The Value field is set to default value 0.
   The two bytes of padding MUST be set to zero and ignored on receipt.

   The inclusion of this TLV in an OPEN object indicates that the sender
   can perform FlowSpec handling as defined in this document.

5.  PCEP FLOWSPEC Object

   The PCEP FLOWSPEC object defined in this document is compliant with
   the PCEP object format defined in [RFC5440].  It is OPTIONAL in the
   PCReq, PCRep, PCErr, PCInitiate, PCRpt, and PCUpd messages and MAY be
   present zero, one, or more times.  Each instance of the object
   specifies a traffic flow.

   The PCEP FLOWSPEC object carries a FlowSpec filter rule encoded in a
   TLV (as defined in Section 6.

   The FLOWSPEC Object-Class is TBD3 (to be assigned by IANA).

   The FLOWSPEC Object-Type is 1.

   The format of the body of the PCEP FLOWSPEC object is shown in
   Figure 2
















Dhody, et al.            Expires April 19, 2019                 [Page 8]


Internet-Draft                PCEP-FlowSpec                 October 2018


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                            FS-ID                              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         AFI                   |  Reserved     |   Flags     |R|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   |                   Flow Filter TLV (variable)                  |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                Figure 2: PCEP FLOWSPEC Object Body Format

   FS-ID (32-bits): A PCEP-specific identifier for the FlowSpec
   information.  A PCE or PCC creates an FS-ID for each FlowSpec that it
   originates, and the value is unique within the scope of that PCE or
   PCC and is constant for the lifetime of a PCEP session.  All
   subsequent PCEP messages can identify the FlowSpec using the FS-ID.
   The values 0 and 0xFFFFFFFF are reserved and MUST NOT be used.

   AFI (16-bits): Address Family Identifier as used in BGP [RFC4760]
   (AFI=1 for IPv4 or VPNv4, AFI=2 for IPv6 and VPNv6 as per as per
   [I-D.ietf-idr-flow-spec-v6]).

   Reserved (8-bits): MUST be set to zero on transmission and ignored on
   receipt.

   Flags (8-bits): One flag is currently assigned -

      R bit: The Remove bit is set when a PCEP FLOWSPEC Object is
      included in a PCEP message to indicate removal of the Flow
      Specification from the associated tunnel.  If the bit is clear,
      the Flow Specification is being added or modified.

      Unassigned bits MUST be set to zero on transmission and ignored on
      receipt.

   If the PCEP speaker receives a message with R bit set in FLOWSPEC
   object and the Flow Specification identified with a FS-ID does not
   exist, it MUST generate a PCErr with Error-type TBD8 (FlowSpec
   Error), error-value 4 (Unknown FlowSpec).

   If the PCEP speaker does not understand or support the AFI in the
   FLOWSPEC message, the PCEP peer MUST respond with a PCErr message
   with error-type TBD8 (FlowSpec Error), error-value 2 (Malformed
   FlowSpec).



Dhody, et al.            Expires April 19, 2019                 [Page 9]


Internet-Draft                PCEP-FlowSpec                 October 2018


   Flow Filter TLV (variable): One TLV MAY be included.

   The Flow Filter TLV is OPTIONAL when the R bit is set.  The TLV MUST
   be present when the R bit is clear.  If the TLV is missing when the R
   bit is clear, the PCEP peer MUST respond with a PCErr message with
   error-type TBD8 (FlowSpec Error), error-value 2 (Malformed FlowSpec).

6.  Flow Filter TLV

   A new PCEP TLV is defined to convey Flow Specification filtering
   rules that specify what traffic is carried on a path.  The TLV
   follows the format of all PCEP TLVs as defined in [RFC5440].  The
   Type field values come from the codepoint space for PCEP TLVs and has
   the value TBD4.

   The Value field contains one or more sub-TLVs (the Flow Specification
   TLVs) as defined in Section 7.  Only one Flow Filter TLV can be
   present and represents the complete definition of a Flow
   Specification for traffic to be placed on the tunnel indicated by the
   PCEP message in which the PCEP Flow Spec Object is carried.  The set
   of Flow Specification TLVs in a single instance of a Flow Filter TLV
   are combined to indicate the specific Flow Specification.

   Further Flow Specifications can be included in a PCEP message by
   including additional Flow Spec objects.

7.  Flow Specification TLVs

   The Flow Filter TLV carries one or more Flow Specification TLV.  The
   Flow Specification TLV follows the format of all PCEP TLVs as defined
   in [RFC5440], however, the Type values are selected from a separate
   IANA registry (see Section 10) rather than from the common PCEP TLV
   registry.

   Type values are chosen so that there can be commonality with Flow
   Specifications defined for use with BGP [RFC5575].  This is possible
   because the BGP Flow Spec encoding uses a single octet to encode the
   type where as PCEP uses two octets.  Thus the space of values for the
   Type field is partitioned as shown in Figure 3.












Dhody, et al.            Expires April 19, 2019                [Page 10]


Internet-Draft                PCEP-FlowSpec                 October 2018


   Range          |
   ---------------+---------------------------------------------------
   0              | Reserved - must not be allocated.
                  |
   1 .. 255       | Per BGP registry defined by [RFC5575] and
                  | [I-D.ietf-idr-flow-spec-v6].
                  | Not to be allocated in this registry.
                  |
   256 ..   65535 | New PCEP Flow Specifications allocated according
                  | to the registry defined in this document.


               Figure 3: Flow Specification TLV Type Ranges

   [RFC5575] created the registry "Flow Spec Component Types" and made
   allocations to it.  [I-D.ietf-idr-flow-spec-v6] requested for another
   registry "Flow Spec IPv6 Component Types" and requested initial
   allocations in it.  If the AFI (in the FLOWSPEC object) is set to
   IPv4, the range 1..255 is as per "Flow Spec Component Types"
   [RFC5575]; if the AFI is set to IPv6, the range 1..255 is as per
   "Flow Spec IPv6 Component Types" [I-D.ietf-idr-flow-spec-v6].  When
   future BGP specifications (such as [I-D.ietf-idr-flowspec-l2vpn])
   make further allocations to the aforementioned registries, they are
   also inherited to be used in PCEP.

   The content of the Value field in each TLV is specific to the type/
   AFI and describes the parameters of the Flow Specification.  The
   definition of the format of many of these Value fields is inherited
   from BGP specifications as shown in Figure 6.  Specifically, the
   inheritance is from [RFC5575] and [I-D.ietf-idr-flow-spec-v6], but
   may also be inherited from future BGP specifications.  This is a non-
   exhaustive list for illustration purpose.

   When multiple Flow Specification TLVs are present in a single Flow
   Filter TLV they are combined to produce a more detailed description
   of a flow.  For examples and rules about how this is achieved, see
   [RFC5575].

   An implementation that receives a PCEP message carrying a Flow
   Specification TLV with a type value that it does not recognize or
   does not support MUST respond with a PCErr message with error-type
   TBD8 (FlowSpec Error), error-value 1 (Unsupported FlowSpec) and MUST
   NOT install the Flow Specification.

   When used in other protocols (such as BGP) these Flow Specifications
   are also associated with actions to indicate how traffic matching the
   Flow Specification should be treated.  In PCEP, however, the only
   action is to associate the traffic with a tunnel and to forward



Dhody, et al.            Expires April 19, 2019                [Page 11]


Internet-Draft                PCEP-FlowSpec                 October 2018


   matching traffic on to that path, so no encoding of an action is
   needed.

   Section 8.7 describes how overlapping Flow Specifications are
   prioritized and handled.

   All Flow Specification TLVs with Types in the range 1 to 255 have
   Values defined for use in BGP (for example, in [RFC5575],
   [I-D.ietf-idr-flow-spec-v6], and [I-D.ietf-idr-flowspec-l2vpn]) and
   are set using the BGP encoding, but without the type or length octets
   (the relevant information is in the Type and Length fields of the
   TLV).  The Value field is padded with trailing zeros to achieve
   4-byte alignment.

   This document defines following new types -


   +-------+-------------------------+-----------------------------+
   | Type  | Description             | Value defined in            |
   |       |                         |                             |
   +-------+-------------------------+-----------------------------+
   | TBD5  | Route Distinguisher     | [I-D.dhodylee-pce-pcep-ls]  |
   +-------+-------------------------+-----------------------------+
   | TBD6  | IPv4 Multicast Flow     | [This.I-D]                  |
   +-------+-------------------------+-----------------------------+
   | TBD7  | IPv6 Multicast Flow     | [This.I-D]                  |
   +-------+-------------------------+-----------------------------+



      Figure 4: Table of Flow Specification TLV Types defined in this
                                 document

   [I-D.dhodylee-pce-pcep-ls] defines a way to convey identification of
   a VPN in PCEP via a Route Distinguisher (RD) [RFC4364] encoded in
   ROUTE-DISTINGUISHER TLV.  A Flow Specification TLV with Type TBD5
   carries a Value field matching that present in the ROUTE-
   DISTINGUISHER TLV and is used to identify that other flow filter
   information (for example, an IPv4 destination prefix) is associated
   with a specific VPN identified by the RD.  See Section 8.6 for
   further discussion of VPN identification.

   Although it may be possible to describe a multicast Flow
   Specification from the combination of other Flow Specification TLVs
   with specific values, it is more convenient to use a dedicated Flow
   Specification TLV.  Flow Specification TLVs with Type values TBD6 and
   TBD7 are used to identify a multicast flow for IPv4 and IPv6
   respectively.  The Value field is encoded as shown in Figure 5.



Dhody, et al.            Expires April 19, 2019                [Page 12]


Internet-Draft                PCEP-FlowSpec                 October 2018


    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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Rsvd  |S|W|R|    Rsvd   |B|Z|  Src Mask Len | Grp Mask Len  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ~                        Source Address                         ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ~                   Group multicast Address                     ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


            Figure 5: Multicast Flow Specification TLV Encoding

   The fields of the two Multicast Flow Specification TLVs are as
   described in Section 4.9.1 of [RFC7761] noting that the two address
   fields are 32 bits for the IPv4 Multicast Flow and 128 bits for the
   IPv6 Multicast Flow.  Reserved fields (RSVD) MUST be set to zero and
   ignored on receipt.

8.  Detailed Procedures

   This section outlines some specific detailed procedures for using the
   protocol extensions defined in this document.

8.1.  Default Behavior and Backward Compatibility

   The default behavior is that no Flow Specification is applied to a
   tunnel.  That is, the default is that the Flow Spec object is not
   used as is the case in all systems before the implementation of this
   specification.

   In this case it is a local matter (such as through configuration) how
   tunnel head ends are instructed what traffic to place on a tunnel.

   [RFC5440] describes how receivers respond when they see unknown PCEP
   objects.

8.2.  Composite Flow Specifications

   Flow Specifications may be represented by a single Flow Specification
   TLV or may require a more complex description using multiple Flow
   Specification TLVs.  For example, a flow indicated by a source-
   destination pair of IPv6 addresses would be described by the
   combination of Destination IPv6 Prefix and Source IPv6 Prefix Flow
   Specification TLVs.






Dhody, et al.            Expires April 19, 2019                [Page 13]


Internet-Draft                PCEP-FlowSpec                 October 2018


8.3.  Modifying Flow Specifications

   A PCE may want to modify a Flow Specification associated with a
   tunnel, or a PCC may want to report a change to the Flow
   Specification it is using with a tunnel.

   It is important that the specific Flow Specification is identified so
   that it is clear that this is a modification of an existing flow and
   not the addition of a new flow as described in Section 8.4.  The FS-
   ID field of the PCEP Flow Spec Object is used to identify a specific
   Flow Specification.

   When modifying a Flow Specification, all Flow Specification TLVs for
   the intended specification of the flow MUST be included in the PCEP
   Flow Spec Object and the FS-ID MUST be retained from the previous
   description of the flow.

8.4.  Multiple Flow Specifications

   It is possible that multiple flows will be place on a single tunnel.
   In some cases it is possible to to define these within a single PCEP
   Flow Spec Object: for example, two Destination IPv4 Prefix TLVs could
   be included to indicate that packets matching either prefix are
   acceptable.  PCEP would consider this as a single Flow Specification
   identified by a single FS-ID.

   In other scenarios the use of multiple Flow Specification TLVs would
   be confusing.  For example, if flows from A to B and from C to D are
   to be included then using two Source IPv4 Prefix TLVs and two
   Destination IPv4 Prefix TLVs would be confusing (are flows from A to
   D included?).  In these cases, each Flow Specification is carried in
   its own PCEP Flow Spec Object with multiple objects present on a
   single PCEP message.  Use of separate objects also allows easier
   removal and modification of Flow Specifications.

8.5.  Adding and Removing Flow Specifications

   The Remove bit in the the PCEP Flow Spec Object is left clear when a
   Flow Specification is being added or modified.

   To remove a Flow Specification, a PCEP Flow Spec Object is included
   with the FS-ID matching the one being removed, and the R bit set to
   indicate removal.  In this case it is not necessary to include any
   Flow Specification TLVs.

   If the R bit is set and Flow Specification TLVs are present an
   implementation MAY ignore them.  If the implementation checks the
   Flow Specification TLVs against those recorded for the FS-ID of the



Dhody, et al.            Expires April 19, 2019                [Page 14]


Internet-Draft                PCEP-FlowSpec                 October 2018


   Flow Specification being removed and finds a mismatch, the Flow
   Specification MUST still be removed and the implementation SHOULD
   record a local exception or log.

8.6.  VPN Identifiers

   VPN instances are identified in BGP using Route Distinguishers (RDs)
   [RFC4364].  These values are not normally considered to have any
   meaning outside of the network, and they are not encoded in data
   packets belonging to the VPNs.  However, RDs provide a useful way of
   identifying VPN instances and are often manually or automatically
   assigned to VPNs as they are provisioned.

   Thus the RD provides a useful way to indicate that traffic for a
   particular VPN should be placed on a given tunnel.  The tunnel head
   end will need to interpret this Flow Specification not as a filter on
   the fields of data packets, but using the other mechanisms that it
   already uses to identify VPN traffic.  This could be based on the
   incoming port (for port-based VPNs) or may leverage knowledge of the
   VRF that is in use for the traffic.

8.7.  Priorities and Overlapping Flow Specifications

   TBD

   An implementation that receives a PCEP message carrying a Flow
   Specification that it cannot resolve against other Flow
   Specifications already installed MUST respond with a PCErr message
   with error-type TBD8 (FlowSpec Error), error-value 3 (Unresolvable
   conflict) and MUST NOT install the Flow Specification.

9.  PCEP Messages

   The figures in this section use the notation defined in [RFC5511].

   The FLOWSPEC Object is OPTIONAL and MAY be carried in the PCEP
   messages.

   The PCInitiate message is defined in [RFC8281] and updated as below:












Dhody, et al.            Expires April 19, 2019                [Page 15]


Internet-Draft                PCEP-FlowSpec                 October 2018


   <PCInitiate Message> ::= <Common Header>
                            <PCE-initiated-lsp-list>

   Where:
      <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-instantiation> ::= <SRP>
                                            <LSP>
                                            [<END-POINTS>]
                                            <ERO>
                                            [<attribute-list>]
                                            [<flowspec-list>]

      Where:
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]


   The PCUpd message is defined in [RFC8231] and updated as below:


   <PCUpd Message> ::= <Common Header>
                       <update-request-list>

   Where:
      <update-request-list> ::= <update-request>
                                [<update-request-list>]

      <update-request> ::= <SRP>
                           <LSP>
                           <path>
                           [<flowspec-list>]

      Where:
         <path>::= <intended-path><intended-attribute-list>

         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]


   The PCRpt message is defined in [RFC8231] and updated as below:







Dhody, et al.            Expires April 19, 2019                [Page 16]


Internet-Draft                PCEP-FlowSpec                 October 2018


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

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

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

       Where:
         <path>::= <intended-path>
                   [<actual-attribute-list><actual-path>]
                   <intended-attribute-list>

         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]


   The PCReq message is defined in [RFC5440] and updated in [RFC8231],
   it is further updated below for flow specification:


   <PCReq Message>::= <Common Header>
                      [<svec-list>]
                      <request-list>

   Where:
      <svec-list>::= <SVEC>[<svec-list>]

      <request-list>::= <request>[<request-list>]

      <request>::= <RP>
                   <END-POINTS>
                   [<LSP>]
                   [<LSPA>]
                   [<BANDWIDTH>]
                   [<metric-list>]
                   [<RRO>[<BANDWIDTH>]]
                   [<IRO>]
                   [<LOAD-BALANCING>]
                   [<flowspec-list>]

      Where:
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]






Dhody, et al.            Expires April 19, 2019                [Page 17]


Internet-Draft                PCEP-FlowSpec                 October 2018


   The PCRep message is defined in [RFC5440] and updated in [RFC8231],
   it is further updated below for flow specification:


   <PCRep Message> ::= <Common Header>
                       <response-list>

   Where:
      <response-list>::=<response>[<response-list>]

      <response>::=<RP>
                  [<LSP>]
                  [<NO-PATH>]
                  [<attribute-list>]
                  [<path-list>]
                  [<flowspec-list>]

      Where:
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]


10.  IANA Considerations

   IANA maintains the "Path Computation Element Protocol (PCEP) Numbers"
   registry.  This document requests IANA actions to allocate code
   points for the protocol elements defined in this document.

10.1.  PCEP Objects

   Each PCEP object has an Object-Class and an Object-Type.  IANA
   maintains a subregistry called "PCEP Objects".  IANA is requested to
   make an assignment from this subregistry as follows:


   Object-Class | Value Name  | Object-Type            |  Reference
   -------------+-------------+------------------------+----------------
      TBD3      | FLOWSPEC    |  0: Reserved           |  [This.I-D]
                |             |  1: Flow Specification |  [This.I-D]


10.1.1.  PCEP FLOWSPEC Object Flag Field

   This document requests that a new sub-registry, named "FLOW SPEC
   Object Flag Field", is created within the "Path Computation Element
   Protocol (PCEP) Numbers" registry to manage the Flag field of the
   FLOWSPEC object.  New values are to be assigned by Standards Action
   [RFC8126].  Each bit should be tracked with the following qualities:




Dhody, et al.            Expires April 19, 2019                [Page 18]


Internet-Draft                PCEP-FlowSpec                 October 2018


   o  Bit number (counting from bit 0 as the most significant bit)

   o  Capability description

   o  Defining RFC

   The following values are defined in this document:


    Bit     Description           Reference

     31     Remove (R-bit)        [This.I-D]



10.2.  PCEP TLV Type Indicators

   IANA maintains a subregistry called "PCEP TLV Type Indicators".  IANA
   is requested to make an assignment from this subregistry as follows:


   Value   | Meaning                      | Reference
   --------+------------------------------+-------------
    TBD2   | PCE-FLOWSPEC-CAPABILITY TLV  | [This.I-D]
    TBD4   | FLOW FILTER TLV              | [This.I-D]


10.3.  Flow Specification TLV Type Indicators

   IANA is requested to create a new subregistry call the "PCEP Flow
   Specification TLV Type Indicators" registry.

   Allocations from this registry are to be made according to the
   following assignment policies [RFC8126]:

















Dhody, et al.            Expires April 19, 2019                [Page 19]


Internet-Draft                PCEP-FlowSpec                 October 2018


   Range          | Assignment policy
   ---------------+---------------------------------------------------
   0              | Reserved - must not be allocated.
                  |
   1 .. 255       | Reserved - must not be allocated.
                  | Usage mirrors the BGP FlowSpec registry [RFC5575]
                  | & [I-D.ietf-idr-flow-spec-v6].
                  |
   256 ..   64506 | Specification Required
                  |
   64507 .. 65531 | First Come First Served
                  |
   65532 .. 65535 | Experimental


   IANA is requested to pre-populate this registry with values defined
   in this document as follows, taking the new values from the range 256
   to 64506:


    Value | Meaning
   -------+------------------------
    TBD5  | Route Distinguisher
    TBD6  | IPv4 Multicast
    TBD7  | IPv6 Multicast


10.4.  PCEP Error Codes

   IANA maintains a subregistry called "PCEP-ERROR Object Error Types
   and Values".  Entries in this subregistry are described by Error-Type
   and Error-value.  IANA is requested to make the following assignment
   from this subregistry:


    Error-| Meaning            | Error-value                | Reference
    Type  |                    |                            |
   -------+--------------------+----------------------------+-----------
    TBD8  | FlowSpec error     | 0: Unassigned              | [This.I-D]
          |                    | 1: Unsupported FlowSpec    | [This.I-D]
          |                    | 2: Malformed FlowSpec      | [This.I-D]
          |                    | 3: Unresolvable conflict   | [This.I-D]
          |                    | 4: Unknown FlowSpec        | [This.I-D]
          |                    | 5-255: Unassigned          | [This.I-D]







Dhody, et al.            Expires April 19, 2019                [Page 20]


Internet-Draft                PCEP-FlowSpec                 October 2018


10.5.  PCE Capability Flag

   IANA maintains a subregistry called "Open Shortest Path First v2
   (OSPFv2) Parameters" with a sub-registry called "Path Computation
   Element (PCE) Capability Flags".  IANA is requested to assign a new
   capability bit from this registry as follows:


    Bit   | Capability Description        | Reference
   -------+-------------------------------+------------
    TBD1  | FlowSpec                      | [This.I-D]


11.  Security Considerations

   We may assume that a system that utilizes a remote PCE is subject to
   a number of vulnerabilities that could allow spurious LSPs or SR
   paths to be established or that could result in existing paths being
   modified or torn down.  Such systems, therefore, apply security
   considerations as described in [RFC5440], [RFC6952], and [RFC8253].

   The description of Flow Specifications associated with paths set up
   or controlled by a PCE add a further detail that could be attacked
   without tearing down LSPs or SR paths, but causing traffic to be
   misrouted within the network.  Therefore, the use of the security
   mechanisms for PCEP referenced above is important.

   Visibility into the information carried in PCEP does not have direct
   privacy concerns for end-users' data, however, knowledge of how data
   is routed in a network may make that data more vulnerable.  Of
   course, the ability to interfere with the way data is routed also
   makes the data more vulnerable.  Furthermore, knowledge of the
   connected end-points (such as multicast receivers or VPN sites) is
   usually considered private customer information.  Therefore,
   implementations or deployments concerned to protect privacy MUST
   apply the mechanisms described in the documents referenced above.

   Experience with Flow Specifications in BGP systems indicates that
   they can become complex and that the overlap of Flow Specifications
   installed in different orders can lead to unexpected results.
   Although this is not directly a security issue per se, the confusion
   and unexpected forwarding behavior may be engineered or exploited by
   an attacker.  Therefore, implementers and operators SHOULD pay
   careful attention to the Manageability Considerations described in
   Section 12.






Dhody, et al.            Expires April 19, 2019                [Page 21]


Internet-Draft                PCEP-FlowSpec                 October 2018


12.  Manageability Considerations

   TBD

13.  Acknowledgements

   Thanks to Julian Lucek and Sudhir Cheruathur for useful discussions.

14.  References

14.1.  Normative References

   [I-D.dhodylee-pce-pcep-ls]
              Dhody, D., Lee, Y., and D. Ceccarelli, "PCEP Extension for
              Distribution of Link-State and TE Information.", draft-
              dhodylee-pce-pcep-ls-11 (work in progress), June 2018.

   [I-D.ietf-idr-flow-spec-v6]
              McPherson, D., Raszuk, R., Pithawala, B.,
              akarch@cisco.com, a., and S. Hares, "Dissemination of Flow
              Specification Rules for IPv6", draft-ietf-idr-flow-spec-
              v6-09 (work in progress), November 2017.

   [I-D.ietf-idr-flowspec-l2vpn]
              Weiguo, H., liangqiandeng, l., Uttaro, J., Litkowski, S.,
              and S. Zhuang, "Dissemination of Flow Specification Rules
              for L2 VPN", draft-ietf-idr-flowspec-l2vpn-08 (work in
              progress), July 2018.

   [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>.

   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760,
              DOI 10.17487/RFC4760, January 2007,
              <https://www.rfc-editor.org/info/rfc4760>.

   [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>.

   [RFC5511]  Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
              Used to Form Encoding Rules in Various Routing Protocol
              Specifications", RFC 5511, DOI 10.17487/RFC5511, April
              2009, <https://www.rfc-editor.org/info/rfc5511>.



Dhody, et al.            Expires April 19, 2019                [Page 22]


Internet-Draft                PCEP-FlowSpec                 October 2018


   [RFC5575]  Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
              and D. McPherson, "Dissemination of Flow Specification
              Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
              <https://www.rfc-editor.org/info/rfc5575>.

   [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>.

   [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>.

14.2.  Informative References

   [I-D.ietf-idr-flowspec-mpls-match]
              Yong, L., Hares, S., liangqiandeng, l., and J. You, "BGP
              Flow Specification Filter for MPLS Label", draft-ietf-idr-
              flowspec-mpls-match-01 (work in progress), December 2016.

   [I-D.ietf-pce-segment-routing]
              Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W.,
              and J. Hardwick, "PCEP Extensions for Segment Routing",
              draft-ietf-pce-segment-routing-14 (work in progress),
              October 2018.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/info/rfc4364>.

   [RFC4655]  Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
              Element (PCE)-Based Architecture", RFC 4655,
              DOI 10.17487/RFC4655, August 2006,
              <https://www.rfc-editor.org/info/rfc4655>.

   [RFC5088]  Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R.
              Zhang, "OSPF Protocol Extensions for Path Computation
              Element (PCE) Discovery", RFC 5088, DOI 10.17487/RFC5088,
              January 2008, <https://www.rfc-editor.org/info/rfc5088>.

   [RFC5089]  Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R.
              Zhang, "IS-IS Protocol Extensions for Path Computation
              Element (PCE) Discovery", RFC 5089, DOI 10.17487/RFC5089,
              January 2008, <https://www.rfc-editor.org/info/rfc5089>.





Dhody, et al.            Expires April 19, 2019                [Page 23]


Internet-Draft                PCEP-FlowSpec                 October 2018


   [RFC6952]  Jethanandani, M., Patel, K., and L. Zheng, "Analysis of
              BGP, LDP, PCEP, and MSDP Issues According to the Keying
              and Authentication for Routing Protocols (KARP) Design
              Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013,
              <https://www.rfc-editor.org/info/rfc6952>.

   [RFC7399]  Farrel, A. and D. King, "Unanswered Questions in the Path
              Computation Element Architecture", RFC 7399,
              DOI 10.17487/RFC7399, October 2014,
              <https://www.rfc-editor.org/info/rfc7399>.

   [RFC7761]  Fenner, B., Handley, M., Holbrook, H., Kouvelas, I.,
              Parekh, R., Zhang, Z., and L. Zheng, "Protocol Independent
              Multicast - Sparse Mode (PIM-SM): Protocol Specification
              (Revised)", STD 83, RFC 7761, DOI 10.17487/RFC7761, March
              2016, <https://www.rfc-editor.org/info/rfc7761>.

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

   [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>.

   [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>.






Dhody, et al.            Expires April 19, 2019                [Page 24]


Internet-Draft                PCEP-FlowSpec                 October 2018


Appendix A.  Flow Specification TLV Types

   [Editor's Note: This section is added for illustration of various
   Types supported, some are inherited from BGP and others are defined
   in this document.  This section might be removed at the time of final
   publication.]


   +-------+-------------------------+-----------------------------+
   | Type  | Description             | Value defined in            |
   |       |                         |                             |
   +-------+-------------------------+-----------------------------+
   | *     | Destination IPv4 Prefix | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Destination IPv6 Prefix | [I-D.ietf-idr-flow-spec-v6] |
   +-------+-------------------------+-----------------------------+
   | *     | Source IPv4 Prefix      | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Source IPv6 Prefix      | [I-D.ietf-idr-flow-spec-v6] |
   +-------+-------------------------+-----------------------------+
   | *     | IP Protocol             | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Next Header             | [I-D.ietf-idr-flow-spec-v6] |
   +-------+-------------------------+-----------------------------+
   | *     | Port                    | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Destination port        | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Source port             | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | ICMP type               | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | ICMP code               | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | TCP flags               | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Packet length           | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | DSCP                    | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Fragment                | [RFC5575]                   |
   +-------+-------------------------+-----------------------------+
   | *     | Flow Label              | [I-D.ietf-idr-flow-spec-v6] |
   +-------+-------------------------+-----------------------------+
   | *     | Ethernet Type           | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | Source MAC              | [I-D.ietf-idr-flowspec-     |



Dhody, et al.            Expires April 19, 2019                [Page 25]


Internet-Draft                PCEP-FlowSpec                 October 2018


   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | Destination MAC         | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | DSAP in LLC             | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | SSAP in LLC             | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | Control field in LLC    | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | SNAP                    | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | VLAN ID                 | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | VLAN COS                | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | Inner VLAN ID           | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | Inner VLAN COS          | [I-D.ietf-idr-flowspec-     |
   |       |                         | l2vpn]                      |
   +-------+-------------------------+-----------------------------+
   | *     | MPLS Label              | [I-D.ietf-idr-flowspec-mpls-|
   |       |                         | match]                      |
   +-------+-------------------------+-----------------------------+
   | TBD5  | Route Distinguisher     | [I-D.dhodylee-pce-pcep-ls]  |
   +-------+-------------------------+-----------------------------+
   | TBD6  | IPv4 Multicast Flow     | [This.I-D]                  |
   +-------+-------------------------+-----------------------------+
   | TBD7  | IPv6 Multicast Flow     | [This.I-D]                  |
   +-------+-------------------------+-----------------------------+

     * Indicates that the TLV Type value comes from the value used
       in BGP.
       This is a non-exhaustive list for illustration purpose.


              Figure 6: Table of Flow Specification TLV Types






Dhody, et al.            Expires April 19, 2019                [Page 26]


Internet-Draft                PCEP-FlowSpec                 October 2018


Appendix B.  Contributors


   Shankara
   Huawei Technologies
   Divyashree Techno Park,
   Whitefield Bangalore,
   Karnataka
   560066
   India

   Email: shankara@huawei.com

   Qiandeng Liang
   Huawei Technologies
   101 Software Avenue,
   Yuhuatai District
   Nanjing
   210012
   China

   Email: liangqiandeng@huawei.com

   Cyril Margaria
   Juniper Networks
   200 Somerset Corporate Boulevard, Suite 4001
   Bridgewater, NJ
   08807
   USA

   Email: cmargaria@juniper.net

   Colby Barth
   Juniper Networks
   200 Somerset Corporate Boulevard, Suite 4001
   Bridgewater, NJ
   08807
   USA

   Email: cbarth@juniper.net

   Xia Chen
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing
   100095
   China




Dhody, et al.            Expires April 19, 2019                [Page 27]


Internet-Draft                PCEP-FlowSpec                 October 2018


   Email: jescia.chenxia@huawei.com

   Shunwan Zhuang
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing
   100095
   China

   Email: zhuangshunwan@huawei.com


Authors' Addresses

   Dhruv Dhody (editor)
   Huawei Technologies
   Divyashree Techno Park, Whitefield
   Bangalore, Karnataka  560066
   India

   Email: dhruv.ietf@gmail.com


   Adrian Farrel (editor)
   Juniper Networks

   Email: adrian@olddog.co.uk


   Zhenbin Li
   Huawei Technologies
   Huawei Bld., No.156 Beiqing Rd.
   Beijing  100095
   China

   Email: lizhenbin@huawei.com















Dhody, et al.            Expires April 19, 2019                [Page 28]


Html markup produced by rfcmarkup 1.128, available from https://tools.ietf.org/tools/rfcmarkup/