[Search] [txt|html|xml|pdf|bibtex] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01                                                         
Network Working Group                                            A. Ryan
Internet-Draft                                        Limelight Networks
Updates: 8006, 8008 (if approved)                           B. Rosenblum
Intended status: Standards Track                                  Vecima
Expires: 25 April 2022                                         N. Sopher
                                                                   Qwilt
                                                         22 October 2021


       CDNI Capacity Insights Capability Advertisment Extensions
            draft-ryan-cdni-capacity-insights-extensions-01

Abstract

   Open Caching architecture is a use case of Content Delivery Networks
   Interconnection (CDNI) in which the commercial Content Delivery
   Network (CDN) is the upstream CDN (uCDN) and the ISP caching layer
   serves as the downstream CDN (dCDN).  This document supplements to
   the CDNI Capability Objects defined in RFC 8008 and CDNI Metadata
   Objects in RFC 8006.  The defined Capability Objects structure and
   interface for advertisments and managment of a downstream CDN
   capacity.

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 25 April 2022.

Copyright Notice

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

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.



Ryan, et al.              Expires 25 April 2022                 [Page 1]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     1.2.  Requirements Language . . . . . . . . . . . . . . . . . .   4
     1.3.  Objectives  . . . . . . . . . . . . . . . . . . . . . . .   4
   2.  CDNI Additonal Capability Objects . . . . . . . . . . . . . .   5
     2.1.  Telemetry Capability Object . . . . . . . . . . . . . . .   5
       2.1.1.  Telemetry Source Object . . . . . . . . . . . . . . .   6
         2.1.1.1.  Telemetry Source Types  . . . . . . . . . . . . .   7
         2.1.1.2.  Telemetry Source Metric Object  . . . . . . . . .   7
       2.1.2.  Telemetry Capability Object Serialization . . . . . .   8
     2.2.  CapacityLimits Capability Object  . . . . . . . . . . . .   9
       2.2.1.  Capacity Limit Object . . . . . . . . . . . . . . . .  10
         2.2.1.1.  Capacity Limit Types  . . . . . . . . . . . . . .  11
         2.2.1.2.  Capacity Limit Telemetry Source Object  . . . . .  11
       2.2.2.  Capacity Limit Object Serialization . . . . . . . . .  12
     2.3.  RequestedCapacityLimits Object  . . . . . . . . . . . . .  13
       2.3.1.  Requsted Limits Object  . . . . . . . . . . . . . . .  14
       2.3.2.  Telemetry Capability Object Serialization . . . . . .  14
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
     3.1.  CDNI Payload Types  . . . . . . . . . . . . . . . . . . .  15
       3.1.1.  CDNI FCI Telemetry Payload Type . . . . . . . . . . .  16
       3.1.2.  CDNI FCI Capacity Limits Payload Type . . . . . . . .  16
       3.1.3.  CDNI MI Requested Capacity Limits Payload Type  . . .  16
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .  17
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  17
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .  17
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  17
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  18

1.  Introduction

   The Streaming Video Alliance [SVA] is a global association that works
   to solve streaming video challenges in an effort to improve end-user
   experience and adoption.  The Open Caching Working Group [OCWG] of
   the Streaming Video Alliance [SVA] is focused on the delegation of
   video delivery requests from commerical CDNs to a caching layer at
   the ISP's network.  Open Caching architecture is a specific use case
   of CDNI where the commercial CDN is the upstream CDN (uCDN) and the
   ISP caching layer is the downstream CDN (dCDN).  While delegating



Ryan, et al.              Expires 25 April 2022                 [Page 2]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   traffic from one CDN to the other, it is important to make sure that
   an appropriate amount of traffic is delegated.  In order to achive
   that, the SVA Open Caching Capacity Insight Specification [OC-CII]
   defines a feedback mechanism to inform the delegator how much traffic
   is appropriate to delegate.  The traffic level information provided
   by that interface will be consumed by entities, such as the Open
   Caching Request router [OC-RR], to help inform that entity's traffic
   delegation decisions.  This document defines and registers CDNI
   Payload Types (as defined at section 7.1 of [RFC8006]).  These
   Payload types are used for Capability Objects added to those defined
   at section 4 of [RFC8008], which are required for the Open Caching
   Capacity Insights Interface [OC-CII].

   For consistency with other CDNI documents this document follows the
   CDNI convention of uCDN (upstream CDN) and dCDN (downstream CDN) to
   represent the commercial CDN and ISP caching layer respectively.

   This document registers two CDNI Payload Types (section 7.1 of
   [RFC8006]) for the defined capability objects:

   *  Telemetry Payload Type: A payload type for the capability object
      which defines the supported telemetry sources, the metrics made
      available by that source, and corresponding configuration
      appropriate to the type of the source (host, port, protocol,
      etc..)

   *  CapacityLimits Payload Type: a payload type for the capability
      object which defines Capacity Limits based on a set of defined
      limit types and a mapping from those limits to corresponding
      telemetry sources for supporting real-time metrics.

   and describes usage of a CDNI Generic Metadata object:

   *  MI.RequestedCapacityLimits: A generic CDNI Metadata object which
      allows the uCDN to solicit the dCDN to reconsider Limits.  This
      object is being proposed as part of CDNI Metadata Model Extensions
      [OC-MME]

1.1.  Terminology

   The following terms are used throughout this document:

   *  CDN - Content Delivery Network

   Additionally, this document reuses the terminology defined in
   [RFC6707], [RFC7336], [RFC8006], [RFC8007], [RFC8008], and [RFC8804].
   Specifically, we use the following CDNI acronyms:




Ryan, et al.              Expires 25 April 2022                 [Page 3]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   *  uCDN, dCDN - Upstream CDN and Downstream CDN respectively (see
      [RFC7336] )

1.2.  Requirements Language

   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.

1.3.  Objectives

   In order to enable information exchange between a uCDN and a dCDN
   about acceptable levels of traffic to delegate, a design has been
   developed as follows:

   In normal operation a uCDN will communicate with a dCDN, via an
   interface, to collect and understand any limits that a dCDN has set
   forth for traffic delegation from a uCDN.  These limits will come in
   the form of metrics such as bits per second, requests per second,
   etc..  These limits can be thought of as Not to Exceed (NTE) limits.

   The dCDN should provide access to a telemetry source of near real
   time metrics that the uCDN can use to track current usage and compare
   that to the limits the dCDN has put forth and adjust traffic
   delegation decisions accordingly to keep current usage under the
   specified limits.  In summary, the dCDN will inform the uCDN of
   limits in how much traffic it should delegate towards the dCDN and
   then provide a telemetry source that the uCDN can use to track its
   current usage.  This allows for a non ambiguous definition of what a
   particular limit means and how to track usage against it.

   Limits that are communicated from the dCDN to the uCDN should be
   considered valid based on the TTL of the response.  The intention is
   that the limits would be long lived and would represent a reasonable
   peak limit that the uCDN should target throughout the course of a
   time period defined by the TTL.

   In the event that a dCDN needs to inform a uCDN of an update to a
   previously communicated limit, the dCDN will be able to leverage a
   uCDN callback endpoint to inform the uCDN of adjusted limits.  The
   most common use case for this would be related to dCDN infrastructure
   issues which reduced the amount of capacity available.

   In the inverse of the above, if a uCDN would like to ask a dCDN to
   reconsider a previously established limit, the uCDN can make a call
   to the dCDN API interface with a proposed limit.  The dCDN can



Ryan, et al.              Expires 25 April 2022                 [Page 4]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   consider the requested limit and choose to send the uCDN an updated
   limit if it meets the dCDN criteria.  This is an asynchronous
   process.  When the uCDN sends the solicitation to the dCDN, the dCDN
   will acknowledge receipt of the request, but will process the request
   with no guarantee that it will trigger an update to any limits.

2.  CDNI Additonal Capability Objects

   Section 5 of [RFC8008] describes the FCI Capability Advertisement
   Object, which contains a CDNI Capability Object as well as the
   capability object type (a CDNI Paylod Type).  The section also
   defines the Capability Objects per such type.  Below we define two
   additional Capability Objects.

   Note: In the following sections, the term "mandatory-to-specify" is
   used to convey which properties MUST be included when serializing a
   given capability object.  When mandatory-to-specify is defined as
   "Yes" for an individual property, it means that if the object
   containing that property is included in an FCI message, then the
   mandatory-to-specify property MUST also be included.

2.1.  Telemetry Capability Object

   The Telemetry Capability Object is used to define a list of telemetry
   sources made available by the dCDN to the uCDN.  Telemetry data is
   being defined as near real time aggregated metics of dCDN
   utilization, such as bits per second egress, and should be specific
   to the uCDN and dCDN traffic delegation relationship.  Telemetry data
   is uniqiely defined by a source id, a metrics name, along with the
   footprints that are associated with an FCI.Capability advertisement.
   Telemetry data is an important component for CDNI delegation.  The
   reasons that Telemetry information is important to traffic delegation
   is as follows: In situations where there are mutiple delegations, a
   uCDN will need to incorporate usage information from it's dCDN in
   such as manner as to allow higher level uCDNs to gain vislibility
   into traffic that is being delegated to a dCDN.  An example of this
   is if a Content Provider delegates traffic directly to a CDN, and
   that CDN decides to further delegate traffic to a dCDN, if the
   Content Provider polls the uCDN for traffic usage, without the uCDN
   integrating the Telemetry data of it's dCDN, any traffic the uCDN
   delegated would become invisible to the Content Provider.  When
   defining a Capacity Limit, the meaning of a limit might be considered
   ambiguous if the uCDN and dCDN are defining current usage via
   different data sources.  Having the dCDN provide a data source
   defining usage that both itself and the uCDN reference, allows a non
   ambiguous metric to use when determing current usage and how that
   compares to a limit




Ryan, et al.              Expires 25 April 2022                 [Page 5]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


      Property: sources

         Description: Telemetry sources made available to the uCDN.

         Type: A JSON array of Telemetry Source objects (see
         Section 2.1.1).

         Mandatory-to-Specify: Yes.

2.1.1.  Telemetry Source Object

   The Telemetry Source Object is built of an associated type, a list of
   exposed metrics, and type-specific configuration data.

      Property: id

         Description: A unique identifier of a telemetry source.

         Type: String.

         Mandatory-to-Specify: Yes.

      Property: type

         Description: A valid telemetry source type.  See
         Section 2.1.1.1.

         Type: String.

         Mandatory-to-Specify: Yes.

      Property: metrics

         Description: The metrics exposed by this source.

         Type: A JSON array of Telemetry Source Metric objects (see
         Section 2.1.1.2).

         Mandatory-to-Specify: Yes.

      Property: configuration










Ryan, et al.              Expires 25 April 2022                 [Page 6]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


         Description: a source-specific representation of the Telemetry
         source configuration.  For the generic source type, this
         configuration format is defined out-of-band.  For other types,
         the configuration format will be specified in a yet to be
         defined Telemetry Interface specification.  The goal of this
         element is to allow for forward compatability with a formal
         Telemetry interface.

         Type: A JSON object: TBD

         Mandatory-to-Specify: No.

2.1.1.1.  Telemetry Source Types

   Below are the listed valid telemetry source types.  At the time of
   this draft, the type registry is limit to a single type of Generic.
   The intention of this type registry is to allow for future extension
   to reference a yet to be drafted specification for a CDNI Telemetry
   interface, which would standardize the definition, format,etc of
   Telemetry data between participants of a CDNI workflow.

          +=============+======================================+
          | Source Type | Description                          |
          +=============+======================================+
          | generic     | An object which allows for           |
          |             | advertisement of generic datasources |
          +-------------+--------------------------------------+

                                 Table 1

2.1.1.2.  Telemetry Source Metric Object

   The Telemetry Source Metric Object describe the metric to be exposed.

      Property: name

         Description: An identifier unique within this telemetry source.

         Type: String.

         Mandatory-to-Specify: Yes.

      Property: time-granularity

         Description: Represents the time frame that the data represents
         in seconds.  I.e. is this a data set over 5 minutes, one hour,
         etc..




Ryan, et al.              Expires 25 April 2022                 [Page 7]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


         Type: Integer.

         Mandatory-to-Specify: No.

      Property: data-percentile

         Description: The percentile calculation the data represents,
         i.e. 50 percentile would equate to the median over the time-
         granularity.  Lack of a data-percentile will mean that the data
         is the average over the time representation.

         Type: Integer.

         Mandatory-to-Specify: No.

      Property: latency

         Description: Time in seconds that the data is behind of real
         time.  This is important to specify to help the uCDN to
         understand how long it might take to reflect traffic
         adjustments in the metrics.

         Type: Integer.

         Mandatory-to-Specify: No.

2.1.2.  Telemetry Capability Object Serialization

   The following shows an example of Telemetry Capability including 2
   metrics for a source, that is scoped to a footprint.





















Ryan, et al.              Expires 25 April 2022                 [Page 8]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   "capabilities": [
     {
       "capability-type": "FCI.Telemetry",
       "capability-value": {
         "sources": [
           {
             "id": "capacity_metrics_region1",
             "type": "generic",
             "metrics": [
               {
                 "name": "egress_5m",
                 "time-granularity": 300,
                 "data-percentile": 50,
                 "latency": 1500
               },
               {
                 "name": "requests_5m",
                  ...
               }
             ]
           }
         ]
       },
       "footprints": [
         <footprint objects>
       ]
     }
   ]


2.2.  CapacityLimits Capability Object

   The Capacity Limits Capability Object enables the dCDN to specify
   traffic delegation limits to a uCDN within an FCI.Capabilities
   advertisement.  The limits specified by the dCDN will inform the uCDN
   on how much traffic can be delegated to the dCDN.  The limits
   specified by the dCDN should be considered Not To Exceed (NTE)
   limits.  The limits should be based on near time telemetry data that
   the dCDN provides to the uCDN.  In any instance where there are
   multiple limits, the uCDN must consider and honor all specified
   limits and use the most restrictive limit when applicable.

      Property: total-limits

         Description: The top level limits for the footprint.  This
         limit represents traffic limits scoped to total delegation from
         the uCDN towards the dCDN.




Ryan, et al.              Expires 25 April 2022                 [Page 9]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


         Type: A JSON array of Capacity Limit objects (see
         Section 2.2.1).

         Mandatory-to-Specify: Yes.

      Property: host-limits

         Description: Limits for particular CDN Domains.  These limits
         are more specific than the total-limits values since they are
         scoped to a particual host value.

         Type: A JSON array of Capacity Limit objects (see
         Section 2.2.1).

         Mandatory-to-Specify: No.

2.2.1.  Capacity Limit Object

   The Capacity Limit Object is a JSON object which will be used with
   the total-limits and host-limits objects.

      Property: limit-type

         Description: The units of maximum-hard and maximum-soft.

         Type: String.  One of the values listed in Section 2.2.1.1.

         Mandatory-to-Specify: Yes.

      Property: maximum-hard

         Description: The maximum unit of capacity that is available for
         use.

         Type: Integer.

         Mandatory-to-Specify: Yes.

      Property: maximum-soft

         Description: A soft limit at which an upstream should consider
         deducing traffic to prevent hitting the hard limit.

         Type: Integer.

         Mandatory-to-Specify: No.

      Property: telemetry-source



Ryan, et al.              Expires 25 April 2022                [Page 10]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


         Description: Mapping of each a particular limit to a specific
         metric with relevant real-time data provided by a telemetry
         source.

         Type: Capcity Limit Telemetry Source object (see
         Section 2.2.1.2).

         Mandatory-to-Specify: No.

      Property: host

         Description: The CDN Domain to which the limit applies.

         Type: String.

         Mandatory-to-Specify: Only when included within a host-limits
         array.

2.2.1.1.  Capacity Limit Types

   Below are listed the valid capacity limit types.  Additional limits
   would need to be specified and extended into this list.  The values
   specified here represent the types that were identified as being the
   most relevant metrics for the purposes of traffic delegation between
   CDNs.

                 +=================+=====================+
                 | Limit Type      | Units               |
                 +=================+=====================+
                 | egress          | Bits per second     |
                 +-----------------+---------------------+
                 | requests        | Requests per second |
                 +-----------------+---------------------+
                 | storage-size    | Total bytes         |
                 +-----------------+---------------------+
                 | storage-objects | Count               |
                 +-----------------+---------------------+
                 | sessions        | Count               |
                 +-----------------+---------------------+
                 | cache-size      | Total bytes         |
                 +-----------------+---------------------+

                                  Table 2

2.2.1.2.  Capacity Limit Telemetry Source Object

   The Capacity Limit Telemetry Source Object refers to a specific
   metric within a Telementry Source.



Ryan, et al.              Expires 25 April 2022                [Page 11]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


      Property: id

         Description: Reference to the "id" of a telemetry source
         defined by a Telemetry Capability object.

         Type: String.

         Mandatory-to-Specify: Yes.

      Property: metric

         Description: Reference to the "name" property of a metric
         defined within a telemetry source of an FCI.Telemetry
         Capability object.

         Type: String.

         Mandatory-to-Specify: Yes.

2.2.2.  Capacity Limit Object Serialization

   The following shows an example of an FCI.CapacityLimits object.

   "capabilities": [
     {
       "capability-type": "FCI.CapacityLimits"
       "capability-value": {
         "total-limits": [
           {
             "limit-type": "egress",
             "maximum-hard": 50000000000,
             "maximum-soft": 25000000000,
             "telemetry-source": {
               "id": "capacity_metrics_region1",
               "metric": "egress_5m"
             }
           }
         ],
         "host-limits": [
           {
             "host": "serviceA.cdn.example.com",
             "limits": [
               "limit-type": "egress",
               "maximum-hard": 20000000000,
               "maximum-soft": 10000000000,
               "telemetry-source": {
                 "id": "capacity_metrics_region1",
                 "metric": "egress_service2_5m"



Ryan, et al.              Expires 25 April 2022                [Page 12]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


               }
             ]
           },
           {
             "host": "serviceB.cdn.example.com",
             "limits": [
               "limit-type": "egress",
               "maximum-hard": 30000000000,
               "maximum-soft": 15000000000,
               "telemetry-source": {
                 "id": "capacity_metrics_region1",
                 "metric": "egress_service2_5m"
               }
             ]
           }
         ]
       },
       "footprints": [
         <footprint objects>
       ]
     }
   ]


2.3.  RequestedCapacityLimits Object

   The MI.RequestedCapacityLimits Generic Metadata object, which is
   cross referenced in CDNI Metadata Model Extensions [OC-MME], is fully
   detailed within this document.  To enable the uCDN to request changes
   in dCDN limits, a new metadata object is introduced.  Using this
   object, a uCDN can request that a dCDN reconsider limits, as defined
   by an FCI.CapacityLimits advertisement.  The
   MI.RequestedCapacityLimits object must be scoped within an
   MI.HostIndex object and as such must be scoped to a host.  The host
   parameter value must be a CDN-Domain that the dCDN has been
   configured to accept requests for.  It is the responsibility of the
   dCDN to make any required adjustments to the
   FCI.CapacityLimits.total-limits if any per host limit updates might
   exceed values specified via the FCI.CapacityLimits.total-limit.  The
   requested limits must specify a footprint, and that footprint should
   be one in which the dCDN has advertised a capability to support.

      Property: requested-limits

         Description: Capacity Limits being requedted by the uCDN to the
         dCDN.





Ryan, et al.              Expires 25 April 2022                [Page 13]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


         Type: A JSON array of Requested Limits objects (see
         Section 2.3.1).

         Mandatory-to-Specify: Yes.

2.3.1.  Requsted Limits Object

   The Requested Limit Object is build of an associated type, a value
   assocaited with the type, and the footprints that the limit should be
   associated with.

      Property: limit-type

         Description: A limit type as defined in Section 2.2.1.1.

         Type: String.

         Mandatory-to-Specify: Yes.

      Property: limit-value

         Description: A unit of capacity defined in the maximum-hard
         property of Section 2.2.1.

         Type: Integer.

         Mandatory-to-Specify: Yes.

      Property: footprints

         Description: The CDNI Footprint objects this requested limit
         are associated with.

         Type: A JSON array of CDNI Footprints (see [RFC8006]).

         Mandatory-to-Specify: Yes.

2.3.2.  Telemetry Capability Object Serialization

   The following shows an example of MI.RequestedCapacityLimits object.











Ryan, et al.              Expires 25 April 2022                [Page 14]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


  {
    "host": "serviceA.cdn.example.com",
    "host-metadata": {
      "metadata": [
        ...,
        {
          "generic-metadata-type": "MI.RequestedCapacityLimits",
          "generic-metadata-value": {
            "requested-limits": [
              {
                "limit-type": "egress",
                "limit-value": 80000000000,
                "footprints": [{
                  "footprint-type": "ipv4cidr",
                  "footprint-value": ["192.0.2.0/24", "198.51.100.0/24"]
                }]
              },
              {
                ...
              }
            ]
          }
        }
      ]
    }
  }


3.  IANA Considerations

3.1.  CDNI Payload Types

   simialr to the type definitions described in section 7.1 of [RFC8006]
   as well as the types described in section 6.1 of [RFC8008].

   This document requests the registration of the three additional
   payload types:














Ryan, et al.              Expires 25 April 2022                [Page 15]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


              +============================+===============+
              | Payload Type               | Specification |
              +============================+===============+
              | FCI.Telemetry              | RFCthis       |
              +----------------------------+---------------+
              | FCI.CapacityLimits         | RFCthis       |
              +----------------------------+---------------+
              | MI.RequestedCapacityLimits | RFCthis       |
              +----------------------------+---------------+

                                 Table 3

   [RFC Editor: Please replace RFCthis with the published RFC number for
   this document.]

3.1.1.  CDNI FCI Telemetry Payload Type

      Purpose: The purpose of this Payload Type is to list the supported
      telemetry sources and the metrics made available by each source).

      Interface: FCI.

      Encoding: See section Section 2.1.

3.1.2.  CDNI FCI Capacity Limits Payload Type

      Purpose: The purpose of this Payload Type is to define Capacity
      Limits based on a utilization metrics corresponding to telemetry
      sources provided by the dCDN.

      Interface: FCI.

      Encoding: See section Section 2.2.

3.1.3.  CDNI MI Requested Capacity Limits Payload Type

      Purpose: The purpose of this Payload Type is to allow a uCDN to
      request a CapacityLimit update from a dCDN

      Interface: MI.

      Encoding: See section Section 2.3.









Ryan, et al.              Expires 25 April 2022                [Page 16]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


4.  Security Considerations

   This specification is in accordance with the CDNI Request Routing:
   Footprint and Capabilities Semantics.  As such, it is subject to the
   security and privacy considerations as defined in Section 8 of
   [RFC8006] and in Section 7 of [RFC8008] respectively.

5.  Acknowledgements

   The authors would like to express their gratitude to TBD for TBD
   (their guidance / contribution / reviews ...)

6.  References

6.1.  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,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC8006]  Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma,
              "Content Delivery Network Interconnection (CDNI)
              Metadata", RFC 8006, DOI 10.17487/RFC8006, December 2016,
              <https://www.rfc-editor.org/info/rfc8006>.

   [RFC8007]  Murray, R. and B. Niven-Jenkins, "Content Delivery Network
              Interconnection (CDNI) Control Interface / Triggers",
              RFC 8007, DOI 10.17487/RFC8007, December 2016,
              <https://www.rfc-editor.org/info/rfc8007>.

   [RFC8008]  Seedorf, J., Peterson, J., Previdi, S., van Brandenburg,
              R., and K. Ma, "Content Delivery Network Interconnection
              (CDNI) Request Routing: Footprint and Capabilities
              Semantics", RFC 8008, DOI 10.17487/RFC8008, December 2016,
              <https://www.rfc-editor.org/info/rfc8008>.

   [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>.

   [RFC8804]  Finkelman, O. and S. Mishra, "Content Delivery Network
              Interconnection (CDNI) Request Routing Extensions",
              RFC 8804, DOI 10.17487/RFC8804, September 2020,
              <https://www.rfc-editor.org/info/rfc8804>.

6.2.  Informative References




Ryan, et al.              Expires 25 April 2022                [Page 17]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   [OC-CII]   Ryan, A., Ed., Rosenblum, B., Goldstein, G., Roskin, R.,
              and G. Bichot, "Open Caching Capacity Insights -
              Functional Specification (Placeholder before
              publication)",
              <https://www.streamingvideoalliance.org/books/open-cache-
              capacity-insights-functional-specification/>.

   [OC-MME]   Goldstein, G., Ed., Power, W., Bichot, G., and A. Siloniz,
              "CDNI Metadata Model Extensions", Version 00, 3 January
              2022, <https://datatracker.ietf.org/doc/html/draft-
              goldstein-cdni-metadata-model-extensions-00>.

   [OC-RR]    Finkelman, O., Ed., Hofmann, J., Klein, E., Mishra, S.,
              Ma, K., Sahar, D., and B. Zurat, "Open Caching Request
              Routing - Functional Specification", Version 1.1, 4
              October 2019,
              <https://www.streamingvideoalliance.org/books/open-cache-
              request-routing-functional-specification/>.

   [OCWG]     "Open Caching Home Page",
              <https://opencaching.streamingvideoalliance.org/>.

   [RFC6707]  Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content
              Distribution Network Interconnection (CDNI) Problem
              Statement", RFC 6707, DOI 10.17487/RFC6707, September
              2012, <https://www.rfc-editor.org/info/rfc6707>.

   [RFC7336]  Peterson, L., Davie, B., and R. van Brandenburg, Ed.,
              "Framework for Content Distribution Network
              Interconnection (CDNI)", RFC 7336, DOI 10.17487/RFC7336,
              August 2014, <https://www.rfc-editor.org/info/rfc7336>.

   [SVA]      "Streaming Video Alliance Home Page",
              <https://www.streamingvideoalliance.org>.

Authors' Addresses

   Andrew Ryan
   Limelight Networks
   1465 N Scottsdale Road, Suite 500
   Scottsdale
               , AZ 85257
   United States of America

   Email: andrew@andrewnryan.com






Ryan, et al.              Expires 25 April 2022                [Page 18]


Internet-Draft  CDNI Capacity Insights Capability Advert    October 2021


   Ben Rosenblum
   Vecima
   4375 River Green Pkwy #100
   Duluth
               , GA 30096
   United States of America

   Email: ben@rosenblum.dev


   Nir B. Sopher
   Qwilt
   6, Ha'harash
   Hod HaSharon
                4524079
   Israel

   Email: nir@apache.org

































Ryan, et al.              Expires 25 April 2022                [Page 19]