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Versions: (draft-svshah-interdomain-sla-exchange) 00 01 02 03 04 05 06 07 08 09 10 11

IDR                                                              S. Shah
Internet-Draft
Intended status: Standards Track                                K. Patel
Expires: February 2, 2018                                    Arrcus, Inc
                                                                S. Bajaj
                                                                 Viptela
                                                             L. Tomotaki
                                                                 Verizon
                                                            M. Boucadair
                                                                  Orange
                                                          August 1, 2017


  Inter-domain Traffic Conditioning Agreement (TCA) Exchange Attribute
                   draft-ietf-idr-sla-exchange-11.txt

Abstract

   Network administrators typically enforce Quality of Service (QoS)
   policies according to Traffic Conditioning Agreement (TCA) with their
   providers.  The enforcement of such policies often relies upon
   vendor-specific configuration language.  Both learning of TCA, either
   thru TCA documents or via some other out-of-band method, and
   translating them to vendor specific configuration language is a
   complex, often manual, process and prone to errors.

   This document specifies an optional transitive attribute to signal
   TCA parameters in-band, across administrative boundaries (considered
   as Autonomous Systems (AS)), thus simplifying and facilitating some
   of the complex provisioning tasks in situations where BGP is
   available as a routing protocol.

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 http://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 February 2, 2018.



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Copyright Notice

   Copyright (c) 2017 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
   (http://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.  QoS Attribute Definition  . . . . . . . . . . . . . . . . . .   5
     3.1.  QoS Attribute SubType . . . . . . . . . . . . . . . . . .   6
     3.2.  TCA SubType . . . . . . . . . . . . . . . . . . . . . . .   7
     3.3.  TCA Content for ADVERTISE TCA Event . . . . . . . . . . .   9
       3.3.1.  Supported IPFIX identifiers for Traffic Class
               Elements  . . . . . . . . . . . . . . . . . . . . . .  12
       3.3.2.  Traffic Class Service types and respective TLVs . . .  15
   4.  Originating TCA Notification  . . . . . . . . . . . . . . . .  22
     4.1.  TCA Contexts  . . . . . . . . . . . . . . . . . . . . . .  23
       4.1.1.  TCA Advertisement for Point-to-Point Connection . . .  23
       4.1.2.  TCA Advertisement for Destination AS Multiple Hops
               Away  . . . . . . . . . . . . . . . . . . . . . . . .  24
   5.  QoS Attribute Handling at Forwarding Nodes  . . . . . . . . .  24
     5.1.  BGP Node Capable of Processing QoS Attribute  . . . . . .  24
     5.2.  QoS Attribute Handling at Receiver  . . . . . . . . . . .  25
   6.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .  25
   7.  Deployment Considerations . . . . . . . . . . . . . . . . . .  25
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  27
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  28
   10. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  29
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  29
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  29
     11.2.  Informative References . . . . . . . . . . . . . . . . .  30
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  31








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1.  Introduction

   Typically there is a contractual Traffic Conditioning Agreement (TCA)
   for Quality of Service (QoS) established between a customer and a
   provider or between providers [RFC7297].  This QoS TCA defines the
   nature of the various traffic classes and services needed within each
   traffic class.  The contract may include full line-rate or sub line-
   rate without additional traffic classes, or it may contain additional
   traffic classes and service definitions for those traffic classes.
   Finer granular traffic classes may be based on some standard code
   points (e.g., based on DSCP (Differentiated Services Code Point)) or
   specific set of prefixes.

   Once the contractual QoS TCA is established, QoS TCA parameters are
   enforced in some or all participating devices by deriving those
   parameters into configuration information on respective devices.  The
   network administrator translates the QoS TCA to QoS policies using
   router (vendor) specific provisioning language.  In a multi-vendor
   network, translating TCAs into technology-specific and vendor-
   specific configuration requires the network administrator to consider
   specific configuration of each vendor.  There does not exist any
   standard protocol to translate TCA agreements into technical clauses
   and configurations and thus both the steps of out of band learning of
   negotiated TCA and provisioning them in a vendor specific language
   can be complex and error-prone.

   TCA parameters may have to be exchanged through organizational
   boundaries, thru TCA documents or via some other off-band method, to
   an administrator provisioning actual devices.  For example, to
   provide voice services, the provider may negotiate QoS parameters
   (like min/max rates) for such traffic classified under the EF
   (Expedited Forwarding) codepoint in Diffserv-enabled [RFC2475]
   networks.  The Administrator at the CE (Customer Edge) not only will
   have to know that provider's service for voice traffic is EF-based
   but will also have to know how to implement DSCP EF classification
   rule along with Low Latency Service, and possibly min/max rate
   enforcement for the optimal use of bandwidth, as per vendor specific
   provisioning language.

   The Inter-domain exchange of QoS TCA policy described in this
   document does not require any specific method for the provider in
   establishing TCAs.  It only requires that the provider wishes to send
   the QoS TCA policy via BGP UPDATE [RFC4271] messages from the
   provider to a set of receivers (BGP peers).  In reaction to, a
   receiving router may translate that to relevant QoS policy definition
   on the device.  The TCA negotiation and assurance is outside the
   scope of this document.




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   This document defines a new optional BGP transitive attribute,
   referred as QoS Attribute, which has as one of its sub-types the TCA
   policy.  The BGP node of the originating AS sends this QoS Attribute,
   for prefixes this QoS TCA Policy applies to, in a BGP UPDATE message
   that will be distributed to a list of destination ASes.  The QoS TCA
   policy can be for inbound traffic to the advertising AS or outbound
   traffic from the advertising AS, or both.

   Protocols and data models are being created to standardize setting
   routing configuration parameters within networks.  YANG data models
   [RFC6020] are being developed so that NETCONF ([RFC6241]) or RESTConf
   [RFC8040] can set these standardize in configuration mechanisms.  For
   ephemeral state, the I2RS protocol is being developed to set
   ephemeral state.  While these protocols provide valid configuration
   within a domain or across domains, some providers desire to exchange
   QoS parameters in- band utilizing BGP peering relationships.  This is
   similar to the distribution of Flow Specification information via BGP
   peering relationships (see [RFC5575] and [RFC7674]).

2.  Terminology

   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
   [RFC2119].

   This document makes use of the following terms:

   o  BGP Speaker: A functional component on a BGP capable device that
      functions as per BGP specification.

   o  BGP peers: BGP Speakers adjacent to each other.

   o  QoS Attribute Speaker: A functional component on a BGP capable
      device that produces and/or processes content of the QoS
      Attribute.  A device that is QoS Attribute Speaker is also always
      a BGP Speaker.  However, a BGP Speaker not necessarily always a
      QoS Attribute Speaker.

   o  QoS Attribute content is produced and processed outside the
      function of the BGP Speaker and thus content of the QoS Attribute
      is completely opaque to the BGP Speaker.  At BGP capable device
      where QoS Attribute content is produced, length and value of the
      QoS Attribute is passed from QoS Attribute Speaker to the BGP
      Speaker where BGP Speaker inserts the attribute into the BGP
      UPDATE message with appropriate attribute flags, attribute type,
      and length and value passed from the QoS Attribute Speaker.
      Similarly, a BGP capable device when receives QoS Attribute in the



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      BGP UPDATE message, BGP Speaker extracts QoS Attribute value from
      the message and passes it to the QoS Attribute Speaker where QoS
      Attribute Speaker processes the content from that passed down
      value.  How the content of the QoS Attribute is passed from the
      QoS Attribute Speaker to the BGP Speaker and vice versa is
      implementation specific.

      In the context of use of QoS Attribute for TCA parameters
      exchange, following roles are defined further within the scope of
      the QoS Attribute Speaker.

   o  TCA Producer: This is a QoS Attribute Speaker that produces QoS
      Attribute for the TCA SubType.

   o  TCA Consumer: This is a QoS Attribute Speaker that is intended
      receiver of QoS Attribute with the TCA SubType.

3.  QoS Attribute Definition

   The QoS Attribute is an optional transitive attribute (TBD -
   attribute code to be assigned by IANA) which is applicable to the
   Source AS and NLRIs advertised in the BGP UPDATE message this
   attribute is included in.  The format of the QoS Attribute is shown
   in Figure 1.

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |   Attr flag   | Attr type QoS |                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               |
       ~                                                               ~
       |                     QoS Attr length/value                     |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+..........................

                          Figure 1: QoS attribute

   Attribute flags - 8-bits field


      highest order bit (bit 0) - MUST be set to 1, since this is an
      optional attribute

      2nd higher order bit (bit 1) - MUST be set to 1, since this is a
      transitive attribute

   The content of the QoS Attribute is further specified with flags,
   applicable to QoS Attribute content, and a SubType in a TLV form.




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3.1.  QoS Attribute SubType

   The Value field of the QoS Attribute contains the following:


      QoS Attribute flags

      Tuple (SubType of the QoS Attribute, SubType length, SubType
      value)

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | QoS Attr flags|      SubType  |         SubType length        |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       ~                                                               ~
       |                        SubType value                          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+.........................+

                     Figure 2: Format of QoS Attribute

   QoS Attr flags  - 8-bits field


      All bits of this field are currently un-used.  The space is
      provided for future use.  All bits MUST be set to zero when sent.
      The values (0x01-0xFF) are reserved, and MUST be ignored when
      received.

   SubType  - 8-bits field with following values:


      0x00 = reserved

      0x01 = TCA

      0x02 - 0xf0 = reserved for future use (Standards Action)

      0xf1 - 0xff = Private use

      The only SubType of the QoS Attribute defined in this
      specification is the TCA SubType.

   SubType length  - 16-bits field that specifies length of the SubType
      value in number of octets.

   SubType value  - variable length field, as expressed in SubType




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      length, that contains information about a specified SubType.  For
      the TCA SubType the information is about sender and receiver(s),
      and TCA parameters as described in Section 3.2.

3.2.  TCA SubType

   Format of the TCA SubType Value field is shown in Figure 3.

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |      TCA SubType flags        |     Destination AS count      |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                      Source AS (Advertiser)                   |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                variable list of Destination AS                |
       ~                            ....                               ~
       |                            ....                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |TCAEvnt|             TCA ID            |      TCA length       |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                  TCA Content for TCA Event                    |
       ~                                                               ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

         Figure 3: Format of the TCA SubType of the QoS attribute

   TCA SubType flags  - 16-bits field


      Currently un-used.  All bits in this field MUST be set to 0.  The
      field is defined for the future use.

   Destination AS count  - 16-bits field that specifies count of
      destination ASNs present in the Destination AS list.

      If this count is 0 then that is an error condition which should be
      handled as described in Section 6.

   Source AS  - 32-bits field AS number space as defined in [RFC6793]


      This is the AS where TCA Content is originated from.  The Source
      AS MUST be of the same AS that is originating TCA ID and TCA
      Content.





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      The Source AS value of 0 is illegal and thus should be considered
      an error which should be handled as described in Section 6.

   Destination AS list  - variable length field that holds as many ASN.
      identifiers, each is 32-bits AS number space is defined in
      [RFC6793], as specified in the Destination AS count field.

      List of ASNs for which the TCA is relevant to, each of which is a
      32-bit number.

   TCA Event  - 4-bits field with following values:


      0x0 = reserved

      0x1 = ADVERTISE

      0x2 to 0xf = Reserved for future use

      The only TCA Event defined in this specification is ADVERTISE.

   TCA ID  - 16-bits field that specifies identifier which is unique in
      the scope of Source AS.

      The significance of a TCA ID is in the context of the source that
      is advertising TCA Content.  The TCA ID is not globally unique but
      it MUST be unique within the source AS.

      The TCA ID applies to aggregate traffic to prefixes for a given
      AFI/SAFI that share the same Source AS and TCA ID.


   TCA Length  - 12-bits field that specifies the length of the TCA
      Content.  The length is expressed in octets.  The TCA Content is
      optional for an advertised TCA ID.  If the TCA Content need not be
      there, the TCA length field MUST be set to zero in such a case.

   TCA Content  - A variable length field (optional field)


      The TCA Content field contains TCA parameters relevant to
      specified TCA SubType.  Since the only defined TCA SubType is
      ADVERTISE, this specification describes TCA Content only for the
      ADVERTISE TCA Event.

      If TCA Content field exists in a BGP UPDATE message that contains
      the QoS Attribute with a TCA SubType for TCA Event ADVERTISE,
      format of the TCA Content is as described in Section 3.3.



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      If the TCA Content field does not exist, then the advertised
      message refers to TCA Content advertised in the previous message
      for the same TCA ID.  If there does not exist any prior TCA
      Content to relate to the advertised TCA ID, then receiver, TCA
      Consumer, can ignore the TCA advertisement and it may simply
      update Destination AS count and Destination AS list.

      The lack of a valid prior TCA Content field does not make this
      attribute invalid, so the QoS Attribute MUST be forwarded as a
      valid BGP optional transitive attribute.

3.3.  TCA Content for ADVERTISE TCA Event

   The only TCA Event described in this specification is ADVERTISE.  The
   format of TCA Content for the ADVERTISE Event is shown in Figure 4.

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |dir|       Traffic Class count     | Class Desc Len|           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+           ~
       |                                                               |
       ~                  Traffic Class Description                    ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | Element Count |                                               |
       +-+-+-+-+-+-+-+-+                                               ~
       |                                                               |
       ~                 Traffic Class Element TLVs                    ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       | Service  Count|                                               |
       +-+-+-+-+-+-+-+-+                                               ~
       |                 Traffic Class Service TLVs                    |
       ~                                                               ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       ~  Repeat from Traffic Class Description for next Traffic Class ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                                                               |
       ~    Repeat from direction for TCA in the other direction       ~
       |                                                               |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 4: TCA-Content for ADVERTISE TCA Event




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   TCA Content contains Traffic Class TLVs that is a set of Traffic
   Class Elements (Classifiers) and Traffic Class Service TLVs for a
   list of Traffic Classes specified by Traffic Class count.  This
   Traffic Class TLVs MUST be specified for one direction first and then
   optionally followed by the specification for the other direction.

   dir (Direction)  - 2-bits field that specifies Direction of the
      traffic TCA is applicable to.  The following values are defined:

      0x0 = reserved

      0x1 = incoming, traffic to source AS from destination AS

      0x2 = outgoing, traffic from source AS towards destination AS

      0x3 = for future use

   Traffic Class (Classifier Group) count  - 16 bits field that
      specifies number of Traffic Classes.

      The value of zero (0x00) in this field is a special value which
      means no TCA for the traffic in a specified direction.  When
      Traffic Class count is 0, for a specific direction, the rest of
      the TCA Content fields MUST NOT be encoded, for that specific
      direction.

   Traffic Class Description Len  - 8-bits field that specifies the
      length of the Traffic Class Description field.  The length is
      expressed in octets.

      The value of zero in this field indicates that no Traffic Class
      Description field follows.

   Traffic Class Description  - variable length field, as expressed in
      The Traffic Class Description Len field, MUST carry UTF-8 encoded
      ([RFC3629]) description.

   Traffic Class Elements (Classifier) Count  - 8-bits field that
      specifies the count of Traffic Class Elements.

      The value zero (0x00) means there are no Traffic Class Elements in
      the traffic class, and thus the Traffic Class is to classify rest
      of the traffic not captured otherwise by other Traffic Classes in
      the set for a specified direction.

      Traffic Class that has 0 elements MUST be presented last in the
      advertised list of Traffic Classes for a specific Direction.




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      Otherwise it is considered an error condition which should be
      handled as described in Section 6.

      The QoS Attribute advertised from a specific source MUST NOT have
      more than one such Traffic Classes (Traffic Class with 0 elements
      count).  If there are more than one such Traffic Classes present
      then it is an error condition which should be handled as described
      in Section 6.

   Traffic Class Element TLVs  - (optional) variable length field
      holding as many TLVs specified by the Traffic Class Elements Count
      field.  Each TLV has the following format:

      IPFIX Element Identifier - 8-bits field that specifies IPFIX
      Identifiers listed in Table 1.

      Length of Value field - 8-bits field that specifies the length,
      expressed in octets, of the value field.

      Value - A variable field that specifies a value appropriate for
      the IPFIX Element Identifier.  It is an error, if the value field
      does not contain the appropriate format, which should be handled
      as described in Section 6.  Only the IPFIX elements shown in
      Table 1 are supported.

      Any Traffic Class Element advertised in the QoS Attribute only
      applies to the advertised AFI/SAFI NLRI within the BGP UPDATE
      message the QoS Attribute is contained in.  If a receiver, TCA
      Consumer, receives a BGP UPDATE message with QoS Attribute for an
      unsupported AFI/SAFI then TCA Consumer MAY ignore advertised TCA.
      TCA Consumer MAY update only Destination AS count and Destination
      AS list, and then QoS Attribute and rest of the BGP UPDATE message
      MUST be forwarded as per QoS Attribute and BGP protocol
      specification.

   Traffic Class Service Count  - 8-bits field that specifies count of
      Traffic Class Service TLVs.

      A value of zero is a special value indicating "no bounded service"
      (a.k.a., Best Effort (BE)).

   Traffic Class Service TLVs  - (optional) variable length field with
      the following format for the TLVs

      Traffic Class Service type - 16-bits field that specifies a
      service type.  Each service type is detailed in Section 3.3.2.
      The list of available service types are,




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      0x00 = reserved

      0x01 = COMMITTED_TSPEC

      0x02 = PEAK_TSPEC

      0x03 = COMMITTED_IN_PROFILE_MARKING

      0x04 = COMMITTED_OUT_PROFILE_MARKING

      0x05 = PEAK_OUT_PROFILE_MARKING

      0x06 = DROP_THRESHOLD

      0x07 = RELATIVE_PRIORITY

      0x08 = EFFECTIVE_MAX_RATE

      0x09 = SUB_TRAFFIC_CLASSES

      Length of Value field - 08-bits field that specifies the length of
      the value field.  The length of the value is expressed in octets.

      Value - a variable length field that specifies the value
      appropriate for each of the Service Types.  It is an error, if
      this field does not contain the appropriate format, which should
      be handled as described in Section 6.  The format of the value for
      each of the service types is described in Section 3.3.2

3.3.1.  Supported IPFIX identifiers for Traffic Class Elements

   IPFIX [RFC7012] has well defined identifier set for a large number of
   packet attributes; an IPFIX IANA registry maintains values for packet
   classifier attributes (<https://www.ietf.org/assignments/ipfix/
   ipfix.xml#ipfix-information-elements> ipfix.xml#ipfix-information-
   elements).  Only the IPFIX attributes listed in Table 1 are
   supported.  Any new attribute to be supported by TCA SubType MUST be
   a Standards Action as described in IANA section.

   +-----+-----------------------------+-------------------------------+
   |  ID |             Name            |            Context            |
   +-----+-----------------------------+-------------------------------+
   | 195 |     ipDiffServCodePoint     |   Indicates the value of the  |
   |     |                             |  marking used in the link(s)  |
   |     |                             |  between the TCA Consumer and |
   |     |                             |     TCA Producer domains.     |
   +-----+-----------------------------+-------------------------------+
   | 203 |       mplsTopLabelExp       |   Indicates the value of the  |



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   |     |                             |  marking used in the link(s)  |
   |     |                             |  between the TCA Consumer and |
   |     |                             |     TCA Producer domains.     |
   +-----+-----------------------------+-------------------------------+
   | 244 |        dot1qPriority        |   Indicates the value of the  |
   |     |                             |  marking used in the link(s)  |
   |     |                             |  between the TCA Consumer and |
   |     |                             |     TCA Producer domains.     |
   +-----+-----------------------------+-------------------------------+
   |  8  |      sourceIPv4Address      |   Indicates the source IPv4   |
   |     |                             |    address of an aggregate    |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   |  27 |      sourceIPv6Address      |   Indicates the source IPv6   |
   |     |                             |    address of an aggregate    |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   |  9  |    sourceIPv4PrefixLength   |  Indicates the length of the  |
   |     |                             |      source IPv4 prefix.      |
   +-----+-----------------------------+-------------------------------+
   |  29 |    sourceIPv6PrefixLength   |  Indicates the length of the  |
   |     |                             |      source IPv6 prefix.      |
   +-----+-----------------------------+-------------------------------+
   |  44 |       sourceIPv4Prefix      |   Indicates the source IPv4   |
   |     |                             |     prefix of an aggregate    |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   | 170 |       sourceIPv6Prefix      |   Indicates the source IPv6   |
   |     |                             |     prefix of an aggregate    |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   |  12 |    destinationIPv4Address   |   Indicates the destination   |



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   |     |                             |  IPv4 address of an aggregate |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   |  28 |    destinationIPv6Address   |   Indicates the destination   |
   |     |                             |  IPv6 address of an aggregate |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   |  13 | destinationIPv4PrefixLength |  Indicates the length of the  |
   |     |                             |    destination IPv4 prefix.   |
   +-----+-----------------------------+-------------------------------+
   |  30 | destinationIPv6PrefixLength |  Indicates the length of the  |
   |     |                             |    destination IPv6 prefix.   |
   +-----+-----------------------------+-------------------------------+
   |  45 |    destinationIPv4Prefix    |   Indicates the destination   |
   |     |                             |  IPv4 prefix of an aggregate  |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   | 169 |    destinationIPv6Prefix    |   Indicates the destination   |
   |     |                             |  IPv6 prefix of an aggregate  |
   |     |                             |   traffic over a connection   |
   |     |                             |     subject to a TCA; the     |
   |     |                             | direction is being explicitly |
   |     |                             |   indicated in the ADVERTISE  |
   |     |                             |         Event message.        |
   +-----+-----------------------------+-------------------------------+
   |  4  |      protocolIdentifier     |   Indicates whether any or a  |
   |     |                             |   specific protocol for the   |
   |     |                             |         traffic class.        |
   +-----+-----------------------------+-------------------------------+
   |  7  |     sourceTransportPort     |  This parameter is used only  |
   |     |                             |    for protocols with port    |
   |     |                             | identifiers. It indicates the |
   |     |                             |   source port number for the  |
   |     |                             | transport protocol identified |
   |     |                             |    by "protocolIdentifier".   |
   +-----+-----------------------------+-------------------------------+



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   |  11 |   destinationTransportPort  |  This parameter is used only  |
   |     |                             |    for protocols with port    |
   |     |                             | identifiers. It indicates the |
   |     |                             |  destination port number for  |
   |     |                             |     the transport protocol    |
   |     |                             |         identified by         |
   |     |                             |     "protocolIdentifier".     |
   +-----+-----------------------------+-------------------------------+

                                  Table 1

3.3.2.  Traffic Class Service types and respective TLVs

3.3.2.1.  COMMITTED_TSPEC

   The COMMITTED_TSPEC TLV definition:


      Type - 0x01

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  The length of the value field MUST be
      specified to be 8 octets to hold the value defined as per format
      below.

      Value - COMMITTED_TSPEC value consists of the (r), (b) parameters
      as described in Invocation Information section of [RFC2212] and
      shown in Figure 5.  Note that inheriting the definition of TSPEC
      (Traffic SPECification) here does not enable RFC2212
      functionality.  Only the format of the Traffic Specification is
      used in this specification.

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |        Rate (r) (32-bit IEEE floating point number)           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Burst Size (b) (32-bit IEEE floating point number)           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                  Figure 5: Traffic Class COMMITTED_TSPEC

   Format of Parameters (r) and (b):  are 32-bit IEEE floating point
      numbers.  Positive infinity is represented as an IEEE single
      precision floating-point number with an exponent of all ones and a
      sign mantissa of all zeros.  The format of IEEE floating-point
      numbers is further summarized in [RFC4506].




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   Parameter (r):  indicates committed-rate of the traffic class.  This
      rate indicates the minimum rate, measured in octets of IP
      datagrams per second (a.k.a, bytes per second), that the service
      advertiser is providing for a given class of traffic on
      advertiser's hop.  Note that it does not necessarily translate to
      a minimum rate service to the receiver of a TCA unless the traffic
      class definition clearly represents a sole receiver of a TCA.

   Parameter (b):  indicates maximum burst size, measured in octets of
      IP datagram size.  Since queuing delay can be considered a
      function of burst size (b) and committed-rate (r), in presence of
      non-zero parameter (r), parameter (b) represents bounded delay for
      the Traffic Class.  This delay is a single hop queuing delay when
      TCA is to be implemented at the resource constrained bottleneck.
      In other words this burst size can be considered as a buffer size.
      Value of 0 for parameter (b) means the advertiser does not mandate
      specific bounded delay.

3.3.2.2.  PEAK_TSPEC

   The PEAK_TSPEC TLV definition:


      Type - 0x01

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  The length of the value field MUST be
      specified to be 8 octets to hold the value defined as per format
      below.

      Value - PEAK_TSPEC value consists of the (r), (b) parameters as
      described in Invocation Information section of [RFC2212] and shown
      in Figure 5.  Note that inheriting the definition of TSPEC
      (Traffic SPECification) here does not enable RFC2212
      functionality.  Only the format of the Traffic Specification is
      used in this specification.

       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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |        Rate (r) (32-bit IEEE floating point number)           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Burst Size (b) (32-bit IEEE floating point number)           |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Figure 6: Traffic Class PEAK_TSPEC

   Format of Parameters (r) and (b):  are 32-bit IEEE floating point



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      numbers.  Positive infinity is represented as an IEEE single
      precision floating-point number with an exponent of all ones and a
      sign mantissa of all zeros.  The format of IEEE floating-point
      numbers is further summarized in [RFC4506].

   Parameter (r):  indicates peak-rate of the traffic class.  This rate
      indicates the maximum rate, measured in octets of IP datagrams per
      second (a.k.a, bytes per second), that the service advertiser is
      providing for a given class of traffic on advertiser's hop.

   Parameter (b):  indicates maximum burst size, measured in octets of
      IP datagram size.

   When PEAK_TSPEC TLV is advertised, COMMITTED_TSPEC TLV MUST be
   present in the advertisement.  Advertisement of PEAK_TSPEC TLV
   without COMMITTED_TSPEC TLV MUST be considered an error condition
   which should be handled as described in Section 6.  If committed-rate
   of the TCA is 0 then rate advertised in the COMMITTED_TSPEC shall be
   0.  Note that existence of COMMITTED_TSPEC in TCA advertisement is
   not mandatory nor is it a mandate that COMMITTED_TSPEC and PEAK_TSPEC
   must always go together.  COMMITTED_TSPEC TLV is optional but only
   when there is no PEAK_TSPEC TLV present in the advertised TCA.

   PEAK_TSPEC TLV with rate value of 0 MUST be considered an error
   condition which should be handled as described in Section 6.

3.3.2.3.  COMMITTED_IN_PROFILE_MARKING

   This Traffic Class Service Type defines action performed, by the TCA
   Producer, on packets that are compliant to the committed-rate
   specified in the COMMITTED_TSPEC TLV.  If committed-rate specified in
   the COMMITTED_TSPEC TLV is 0 then TLV for this Traffic Class Service
   Type SHOULD NOT be advertised.  COMMITTED_IN_PROFILE_MARKING TLV
   SHOULD be ignored by the TCA Consumer if there does not exist
   COMMITTED_TSPEC TLV for the specified direction, or committed-rate
   specified in the COMMITTED_TSPEC TLV is 0.

   The COMMITTED_IN_PROFILE_MARKING TLV definition:


      Type - 0x03

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  The length of the value field MUST be
      specified to be 2 octets to hold the value defined as per format
      below.

      Value - contains the Marking code-point type and value



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         Marking code-point type - 8-bits IPFIX Element Identifier.

         Marking code-point value - 8-bits code-point number.

   The marking code-point type of 0x00 is a drop identifier.  When
   marking code-point type value is 0x00 (that is drop), the marking
   code-point value in this case has no meaning and thus the value in
   this field should be ignored.

   The following table lists the supported IPFIX Identifiers.  Any value
   other than 0 or identifier from the following table is an error
   condition which should be handled as described in Section 6.

                       +-----+---------------------+
                       | ID  | Name                |
                       +-----+---------------------+
                       | 195 | ipDiffServCodePoint |
                       | 203 | mplsTopLabelExp     |
                       | 244 | dot1qPriority       |
                       +-----+---------------------+

                                  Table 2

3.3.2.4.  COMMITTED_OUT_PROFILE_MARKING

   This Traffic Class Service Type defines action performed, at the TCA
   Producer, on packets that are not compliant to the committed-rate
   specified in the COMMITTED_TSPEC TLV, and compliant to rate specified
   in the PEAK_TSPEC TLV if PEAK_TSPEC TLV exists.

   The COMMITTED_OUT_PROFILE_MARKING TLV definition:


      Type - 0x04

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  The length of the value field MUST be
      specified to be 2 octets to hold the value defined as per format
      below.

      Value - contains the Marking code-point type and value


         Marking code-point type - 8-bits IPFIX Element Identifier

         Marking code-point value - 8-bits code-point number





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   The marking code-point type of 0x00 is a drop identifier.  When
   marking code-point type value is 0x00 (that is drop), the marking
   code-point value in this case has no meaning and thus the value in
   this field should be ignored.

   Table 2 lists the supported IPFIX Identifiers.  Any value other than
   0 or identifier from the Table 2 is an error condition which should
   be handled as described in Section 6.

3.3.2.5.  PEAK_OUT_PROFILE_MARKING

   This Traffic Class Service Type defines action performed, at the TCA
   Producer, on packets that are not compliant to the max-rate specified
   in the PEAK_TSPEC TLV.  PEAK_OUT_PROFILE_MARKING TLV SHOULD be
   ignored by the TCA Consumer if there does not exist PEAK_TSPEC TLV
   for the specified direction.

   The PEAK_OUT_PROFILE_MARKING TLV definition:


      Type - 0x06

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  The length of the value field MUST be
      specified to be 2 octets to hold the value defined as per format
      below.

      Value - contains the Marking code-point type and value


         Marking code-point type - 8-bits IPFIX Element Identifier

         Marking code-point value - 8-bits code-point number

   The marking code-point type of 0x00 is a drop identifier.  When
   marking code-point type value is 0x00 (that is drop), the marking
   code-point value in this case has no meaning and thus the value in
   this field should be ignored.

   Table 2 lists the supported IPFIX Identifiers.  Any value other than
   0 or identifier from the Table 2 is an error condition which should
   be handled as described in Section 6.

3.3.2.6.  DROP_THRESHOLD

   The DROP_THRESHOLD TLV definition:





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      Type - 0x07

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.

      Value - Count of drop thresholds, followed by content for each
      drop threshold in the form of (code-point type, count of code-
      points, list of code-points, threshold value).

      Count of drop thresholds - 8-bits field that specifies number of
      drop thresholds specified in this TLV.  Content of each drop
      threshold is to follow following format

      Code-point type - 8-bits IPFIX Element Identifier from the list
      shown in Table 6.

      Count of code-points - 8-bits field that specifies number of code-
      point values to follow for a specified code-point type.

      List of code-points - each code-point value is specified in size
      of 8 bits and thus total size for this field is 8 bits multiplied
      by as many number of code-points specified.

      Burst value - This is a fixed size 32-bits IEEE floating point
      number that specifies burst value in unit of bytes.

   All advertised drop thresholds, for a specific traffic class, are
   applicable to a single queue associated with that traffic class.  A
   threshold for a set of code-points is a logical marker where an
   arrived packet is to be tail dropped if overall depth of a queue is
   beyond a threshold of a code-point set, a packet is classified into.
   If a packet can not be classified into any of the advertised code-
   point set then that means the TCA Producer is not defining any
   specific tail drop behavior and thus dropping behavior is subject to
   implementation specific of the TCA Consumer.

                       +-----+---------------------+
                       | ID  | Name                |
                       +-----+---------------------+
                       | 195 | ipDiffServCodePoint |
                       | 203 | mplsTopLabelExp     |
                       | 244 | dot1qPriority       |
                       +-----+---------------------+

                                  Table 3






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3.3.2.7.  RELATIVE_PRIORITY

   The RELATIVE_PRIORITY TLV definition:


      Type - 0x08

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  Given supported range of priority values in
      this specification, the length of the value field MUST be limited
      to and thus MUST be specified exactly as 1 octet.

      Value - A value from range of 0 - 255.  Lower the value means
      higher the priority

   Relative priority indicates scheduling priority of this traffic
   class.  Voice traffic, for example, which requires lowest latency
   compared to any other traffic, may have lowest value advertised in
   relative priority.  For two different traffic classification groups
   where one application group may be considered more important than the
   other but from a scheduling perspective does not require to be
   distinguished with a different priority, relative priority for those
   classification groups may be advertised with the same value.

   A higher priority class of traffic to be served without pre-empted by
   lower priority class of traffic for more than a packet time at the
   configured rate.

   In the system that implements WRR only (no priority queuing), it is
   possible to use a single queue from a group of queues serviced by WRR
   scheduler, where the share of the output bandwidth assigned to that
   queue is equal to advertised rate for that priority.

3.3.2.8.  EFFECTIVE_MAX_RATE

   The EFFECTIVE_MAX_RATE TLV definition:


      Type - 0x02

      Length - 8-bits field that specifies length, expressed in octets,
      of the value field.  The length of the value field MUST be
      specified to be 5 octets to hold the value defined as per format
      below.

      Value - Contains value of rate and per packet overhead





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         Aggregate max rate - 32-bits IEEE floating point number

         Per packet overhead - 8-bits specifying value of overhead
         octets

   Aggregate max rate indicates rate measured based on combined octets
   of packet's IP datagram size and advertised per packet overhead.

   A packet traversing from the TCA Producer to the TCA Consumer or
   vice-versa may see packet overhead, additional octets on top of IP
   datagram size, difference between the Producer and the Consumer sent
   or received over a physical link.  In cases, where advertised TCA is
   for a Consumer where total traffic between Consumer and Producer is
   to be capped to a specific sub-rate of a physical link, due to packet
   overhead differences between Producer and Consumer, sum of traffic
   from each TRAFFIC CLASS may overrun that total cap causing undesired
   behavior.  In such cases, Producer can explicitly notify this TLV in
   advertised TCA.

3.3.2.9.  SUB_TRAFFIC_CLASSES

   The SUB_TRAFFIC_CLASSES TLV definition:


      Type - 0x09

      Length - 16-bits field that specifies total length, expressed in
      octets, of a Traffic Class TLVs encoded in the value field

      Value - A subset of Traffic Class TLVs

   For TCAs where a specific Traffic Class may further be defined by a
   subset of more granular Traffic Classes, with its own set of Traffic
   Class TLVs, SUB_TRAFFIC_CLASSES service type SHOULD be used to
   specify them.

4.  Originating TCA Notification

   The QoS Attribute for the TCA SubType MUST only be added to the BGP
   UPDATE message at the node that is TCA Producer.  Any QoS Attribute
   Speaker, in the path to the TCA Consumer MUST NOT modify content of
   that attribute except modification of the Destination AS list.

   QoS Attribute with the TCA SubType SHOULD NOT be advertised
   periodically just for the purpose of KEEPALIVE between TCA Producer
   and TCA Consumer.  Some sort of TCA policy change, at the TCA
   Producer, may be considered as a trigger for the advertisement.




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   For any modified TCA policy at the TCA Producer, the TCA Producer
   MUST re-advertise the entire set of TCA parameters.  There is no
   provision to advertise partial set of TCA parameters.  Announcing a
   TCA ID different from an earlier advertised one, for the same prefix
   and from the same Source AS, indicates Source AS is advertising new
   TCA Content to replace the previous one advertised with the same TCA
   ID.

   In order to withdraw a given TCA between TCA Producer and TCA
   Consumer, the TCA Produced MUST sent TCA Content with the same TCA
   ID, AS Source, and NLRI prefix, as were used to advertise earlier TCA
   parameters, and the Traffic Class count MUST be set to 0.

4.1.  TCA Contexts

4.1.1.  TCA Advertisement for Point-to-Point Connection

   In certain cases, the advertisement of a TCA is intended to relate to
   aggregate traffic over a point-to-point connection between a specific
   destination and a specific source.  A point-to-point connection may
   be a physical link or a virtual link (e.g. a tunnel).  In such cases,
   a BGP UPDATE message with source AS number and NLRI prefix as an IP
   address of a TCA Producer can uniquely identify physical/virtual link
   in order to establish the context for the advertised TCA for that
   point to point link.

   In the simplest case where Provider (e.g., PE) and Customer (e.g.,
   CE) devices are directly connected via a physical link and have only
   a single link between them, the CE can uniquely identify the
   forwarding link to the PE with the following:

   o  AS number of the PE,

   o  NLRI prefix being an IP address of the PE, that is the next hop
      address from CE to PE.

   The TCA advertised in the QoS Attribute in the BGP UPDATE message
   sent from the PE to a CE, along with the PE's AS number and PE's IP
   address, establishes TCA context for the aggregate traffic through
   CE-to-PE link.

   The TCA advertised in the QoS Attribute in the BGP UPDATE message
   from PE to CE, with PE's AS number and any other prefix, means TCA
   for that specific prefix based traffic, a subset of traffic through
   CE-to-PE link.

   Even though this example is in the context of IP prefixes, QoS
   Attribute's TCA exchange does not have to be limited to the IP



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   address family (IPv4 and IPv6).  TCA advertisement is generic to all
   forms of NLRI types that are supported by the BGP specification (like
   IPv4, IPv6, VPN-IPv4, VPN-IPv6).

   When BGP UPDATE message with the QoS Attribute, containing TCA
   SubType, is triggered for a point-to-point connection (physical or
   logical), the Source AS number in the TCA SubType SHOULD be set to
   TCA Producer's AS number and destination AS number SHOULD be set to
   AS number of BGP peer's that is targeted TCA Consumer.

4.1.2.  TCA Advertisement for Destination AS Multiple Hops Away

   When advertised TCA is not for the BGP peer of a TCA Producer, the
   Source AS field, in the TCA SubType, MUST be set.  The list of
   destination AS(es) also MUST be set, in the TCA SubType, to avoid
   flooding of the QoS Attribute data in the network beyond those
   destinations.  Destination AS(es) is a list of TCA Consumers the
   advertised TCA is intended for.

   If a new prefix is learned and traffic with this new prefix is
   subject to TCA parameters that have already been advertised before
   for other existing prefixes, then the BGP UPDATE for this new prefix
   MAY include QoS Attribute containing just a TCA ID that was
   advertised earlier.  This BGP UPDATE message does not require to have
   the whole TCA Content.  The TCA ID is sufficient to relate TCA
   parameters to new advertised prefixes.

5.  QoS Attribute Handling at Forwarding Nodes

   The propagation of the QoS Attribute in the BGP UPDATE messages
   depends on the rules detailed in the following sub-sections.

5.1.  BGP Node Capable of Processing QoS Attribute

   If a BGP peer is also a QoS Attribute Speaker, it MAY process the QoS
   Attribute.  If BGP UPDATE message has a QoS Attribute with a list of
   destination ASes, QoS Attribute Speaker MAY trim the list and adjust
   the count of the destination AS to exclude ones that are not required
   in further announcement of BGP UPDATE messages.

   A QoS Attribute Speaker MUST drop TCA SubType from the QoS Attribute,
   if there are no more ASes left in the QoS Attribute's destination
   list.  The rest of the QoS Attribute contents may be forwarded if
   there exist other SubTypes of QoS Attribute and forwarding rules meet
   other SubTypes requirements.  If there is no other SubTypes in that
   QoS Attribute content then QoS Attribute Speaker MUST drop the entire
   QoS Attribute all together.  BGP Speaker MAY announce further other




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   attributes and NLRI information, if they meet rules defined by other
   attributes and BGP specification.

   Except extracting the entire TCA SubType of the QoS Attribute and
   trimming the list of Destination AS list, all other content MUST NOT
   be modified by any QoS Attribute Speaker or BGP Speaker in the path
   of a BGP UPDATE message.

5.2.  QoS Attribute Handling at Receiver

   Once QoS Attribute with the TCA SubType is received at intended
   receiver (TCA Consumer) , processing of advertised TCA Content is
   optional for the TCA Consumer.  TCA Consumer MAY just trim the
   Destination AS list as per rules described in this specification,
   without processing any other content of the Attribute.  If Receiver
   chooses to process advertised TCA content, it may encounter errors
   beyond the ones described in this document, errors like
   unavailability of resources if Receiver chooses to implement policies
   for advertised TCA.  In such a case Receiver MAY simply log a
   message.  QoS attribute still MUST be forwarded as per rules defined
   in this document and rest of the BGP UPDATE message MUST be processed
   as per BGP specification.  If intended receiver is not a QoS
   Attribute Speaker than BGP Speaker MUST forward this attribute
   without any change if rest of the BGP UPDATE message also meets
   forwarding rules as per BGP specification.

   When BGP UPDATE messages are triggered only as a result of TCA policy
   change, propagating BGP UPDATE message beyond intended TCA Consumers
   is not necessary.  If the TCA Consumer device implementations are
   capable of policy based filtering, it may implement a policy to
   filter such BGP UPDATE messages based on prefixes and QoS Attribute
   containing TCA SubType.

6.  Error Handling

   Error conditions, while processing of the QoS Attribute content, MUST
   be handled with the approach of attribute discard as described in
   [RFC7606].  Processing of QoS Attribute content is done by QoS
   Attribute Speaker and thus in case of errors, resulting in attribute
   discard, QoS Attribute Speaker SHOULD convey such indication to the
   BGP Speaker and rest of the BGP message SHOULD be processed by the
   BGP Speaker as per BGP specification.

7.  Deployment Considerations

   One of the use cases is for a provider to advertise contracted TCA
   parameters to a Customer Edge (CE) in cases where eBGP is deployed
   between PE and CE.  The TCA parameters may already be provisioned by



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   the provider on the PE device (facing CE).  This provisioned TCA
   parameters are then advertised thru proposed QoS Attribute to the CE
   device.  The CE device may read the QoS Attribute and TCA SubType
   content to implement the QoS policy on the device.

   Contracted TCA from PE to CE may be full line-rate or sub line-rate
   or finer granular controlled services.  The advertised TCA can be
   useful when contracted service is sub-rate of a link and/or when for
   finer granular traffic classes that are controlled (e.g. voice, video
   services may be capped to certain rate).

                               _______________
           __________         /               \
          /          \       /                 \
         /            \     /                   \
         |CustomerSite|-----|      Provider     |
         \           C/E   P\E                  /
          \__________/       \                 /
                              \_______________/
              AS 3                   AS 2

             TCA_ADVERTISE: AS2 to AS3
             NLRI = PE ip address

                           Figure 7: - Example 1

   Another use case can be to advertise TCAs among different network
   sites within one Enterprise network.  In Hub and Spoke deployments,
   Administrator may define TCAs at spoke and advertise QoS TCA
   parameters to the Hub thru BGP updates.  In Figure 7, each spoke (AS1
   and AS2) are connected to Hub (AS3) via a VPN tunnel.  As shown in
   Figure 7, AS2 can advertise TCA to AS3 in the context of that tunnel
   ip address.

                                               AS 2
                      _______________        ________
                     /               \      /        \
        _____       /                 \-----| Spoke2 |
      /      \     /                   \    \________/
      | Hub  |-----|      Provider     |     ________
      \______/     \                   /    /        \
                    \                 /-----| Spoke1 |
       AS 3          \_______________/      \________/
                                              AS 1







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         TCA_ADVERTISE: AS2 to AS3
                        NLRI = AS2 tunnel address

         TCA_ADVERTISE: AS1 to AS3
                        NLRI = AS1 tunnel address

                    Figure 7 - Example 2

   Deployment options are not limited to involving CEs, PE-to-CE or CE-
   to-CE, only.  For any contract between two providers, TCA parameters
   may be advertised from one to the other.

8.  IANA Considerations

   This document defines a new BGP optional transitive path attribute,
   called QoS Attribute.  IANA action is required to allocate a new
   code-point in the BGP path Attributes registry.

   IANA is requested to create a registry for QoS Attribute SubTypes.
   This is a registry of 1 octet value, divided into two pools.One pool
   of numbers to be assigned on a standards action/early allocation
   basis.  The initial assignments are as shown below.  The other pool
   is for the private use,available range for which is as shown below.

       QoS Attribute SubTypes
       ======================
       Reserved       0x00
       TCA            0x01
       Reserved       0x02-0xf0 (Standards Action)
       Private use    0xf1-0xff

   IANA is requested to create a registry for QoS Attribute TCA Event
   Types.  This is a registry of 4-bits value, divided into two pools.
   One pool of numbers to be assigned on a standards action/early
   allocation basis.  One pool of numbers to be assigned on a standards
   action/early allocation basis.  The initial assignments are as shown
   below.  The other pool is for the private use, available range for
   which is as shown below.

       QoS Attribute TCA Event Types
       =============================
       Reserved      0x0
       ADVERTISE     0x1
       Reserved      0x2 - 0xc (Standards Action)
       Private use   0xd - 0xf

   IANA is requested to create a registry to define QoS Attribute TCA
   Direction.  This is the direction in forwarding path, advertised QoS



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   TCA is applicable to.  This is a 2-bit registry.  Values for QoS
   Attribute TCA direction are:

       QoS Attribute TCA Direction
       ===========================
       Reserved                           0x0
       To source AS from destination AS   0x1
       From source AS to destination AS   0x2
       Reserved (Standards Action)        0x3

   QoS Attribute TCA Traffic Class Element Types will be referring to
   existing IPFIX IANA types as listed in Table 1.  While IPFIX registry
   is maintained by IANA out of scope of this specification, the use of
   IPFIX identifiers for this specification are limited to what is
   described in Table 1.  Any new addition of IPFIX identifiers to this
   table should be a Standards Action.

   IANA is requested to create a registry for QoS Attribute TCA Traffic
   Class Service Types.  This is a registry of 2 octet values, to be
   assigned on a standards action/early allocation basis.  The initial
   assignments are:

      Traffic Class Service Type      Value
      ============================   ======
      Reserved                        0x00
      COMMITTED_TSPEC                 0x01
      PEAK_TSPEC                      0x02
      COMMITTED_IN_PROFILE_MARKING    0x03
      COMMITTED_OUT_PROFILE_MARKING   0x04
      PEAK_OUT_PROFILE_MARKING        0x05
      DROP_THRESHOLD                  0x06
      RELATIVE_PRIORITY               0x07
      EFFECTIVE_MAX_RATE              0x08
      SUB_TRAFFIC_CLASSES             0x09
      Standards Action                0x0A   - 0x3FFF
      FCFS                            0x4000 - 0x4FF0

9.  Security Considerations

   BGP security vulnerabilities analysis is documented in [RFC4272],
   while BGP-related security considerations are discussed in [RFC4271].
   Also, the reader may refer to [RFC7132] for more details about BGP
   path threat model.  Means to prevent route hijacking SHOULD be
   enabled.  Such means include RPKI based origin validation [RFC7115]
   and BGP Path validation (e.g., [I-D.ietf-sidr-bgpsec-protocol]).
   Rest of the content in this section discusses additional privacy and
   security considerations that are applicable to the attribute defined
   in this document.



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   The information conveyed in the QoS Attribute TCA SubType reveals
   sensitive data that should not be exposed publicly to non-authorized
   parties.  Deployment considerations mainly target use of QoS
   Attribute and TCA SubType in managed networks and those where a trust
   relationship is in place (Customer to Provider, or Provider to
   Provider).  Administrators MUST disable this attribute to be sent to
   a remote peer which whom no trust relationship is in place.  Both TCA
   Producer and Consumer SHOULD NOT publish valid TCA IDs to non-
   authorized nodes.

   The attribute may be advertised by a misbehaving node to communicate
   TCA parameters that are not aligned with the TCA agreements.  The
   enforcement of TCA parameters is outside the scope of this document.

   The attribute defined in this document may be used by a misbehaving
   node for denial-of-service (e.g., inadequately rate-limit or drop
   some critical traffic).  As a mitigation, a BGP peer MUST accept this
   attribute only from trusted BGP peers.  For example, ACLs may be
   configured to identify the trusted ASes that are allowed to send the
   attribute.  Further, administrators of a TCA Consumer's domain are
   RECOMMENDED to generate TCA ID using pseudo-random schemes [RFC4086].
   Using robust TCA IDs make it hard to guess a valid TCA.

10.  Acknowledgements

   Thanks to Fred Baker, David Black, Sue Hares, Benoit Claise and
   Alvaro Retana for their suggestions and to Christian Jacquenet, Ken
   Briley, Rahul Patel, Fred Yip, Lou Berger, Brian Carpenter, Bertrand
   Duvivier, Bruno Decraene, David Black, and Ron Bonica for the review.

11.  References

11.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2212]  Shenker, S., Partridge, C., and R. Guerin, "Specification
              of Guaranteed Quality of Service", RFC 2212,
              DOI 10.17487/RFC2212, September 1997,
              <http://www.rfc-editor.org/info/rfc2212>.

   [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
              10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
              2003, <http://www.rfc-editor.org/info/rfc3629>.




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

   [RFC4506]  Eisler, M., Ed., "XDR: External Data Representation
              Standard", STD 67, RFC 4506, DOI 10.17487/RFC4506, May
              2006, <http://www.rfc-editor.org/info/rfc4506>.

   [RFC7012]  Claise, B., Ed. and B. Trammell, Ed., "Information Model
              for IP Flow Information Export (IPFIX)", RFC 7012,
              DOI 10.17487/RFC7012, September 2013,
              <http://www.rfc-editor.org/info/rfc7012>.

   [RFC7115]  Bush, R., "Origin Validation Operation Based on the
              Resource Public Key Infrastructure (RPKI)", BCP 185,
              RFC 7115, DOI 10.17487/RFC7115, January 2014,
              <http://www.rfc-editor.org/info/rfc7115>.

   [RFC7606]  Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
              Patel, "Revised Error Handling for BGP UPDATE Messages",
              RFC 7606, DOI 10.17487/RFC7606, August 2015,
              <http://www.rfc-editor.org/info/rfc7606>.

11.2.  Informative References

   [I-D.ietf-sidr-bgpsec-protocol]
              Lepinski, M. and K. Sriram, "BGPsec Protocol
              Specification", draft-ietf-sidr-bgpsec-protocol-22 (work
              in progress), January 2017.

   [RFC2475]  Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
              and W. Weiss, "An Architecture for Differentiated
              Services", RFC 2475, DOI 10.17487/RFC2475, December 1998,
              <http://www.rfc-editor.org/info/rfc2475>.

   [RFC4086]  Eastlake 3rd, D., Schiller, J., and S. Crocker,
              "Randomness Requirements for Security", BCP 106, RFC 4086,
              DOI 10.17487/RFC4086, June 2005,
              <http://www.rfc-editor.org/info/rfc4086>.

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







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   [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,
              <http://www.rfc-editor.org/info/rfc5575>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <http://www.rfc-editor.org/info/rfc6020>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <http://www.rfc-editor.org/info/rfc6241>.

   [RFC6793]  Vohra, Q. and E. Chen, "BGP Support for Four-Octet
              Autonomous System (AS) Number Space", RFC 6793,
              DOI 10.17487/RFC6793, December 2012,
              <http://www.rfc-editor.org/info/rfc6793>.

   [RFC7132]  Kent, S. and A. Chi, "Threat Model for BGP Path Security",
              RFC 7132, DOI 10.17487/RFC7132, February 2014,
              <http://www.rfc-editor.org/info/rfc7132>.

   [RFC7297]  Boucadair, M., Jacquenet, C., and N. Wang, "IP
              Connectivity Provisioning Profile (CPP)", RFC 7297,
              DOI 10.17487/RFC7297, July 2014,
              <http://www.rfc-editor.org/info/rfc7297>.

   [RFC7674]  Haas, J., Ed., "Clarification of the Flowspec Redirect
              Extended Community", RFC 7674, DOI 10.17487/RFC7674,
              October 2015, <http://www.rfc-editor.org/info/rfc7674>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <http://www.rfc-editor.org/info/rfc8040>.

Authors' Addresses

   Shitanshu Shah

   Email: shitanshu_shah@hotmail.com


   Keyur Patel
   Arrcus, Inc

   Email: keyur@arrcus.com



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   Sandeep Bajaj
   Viptela


   Luis Tomotaki
   Verizon
   400 International
   Richardson, TX 75081
   US

   Email: luis.tomotaki@verizon.com


   Mohamed Boucadair
   Orange
   Rennes
   35000
   France

   Email: mohamed.boucadair@orange.com































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