Network Working Group                                     F. Le Faucheur
Internet-Draft                                          M. Viveganandhan
Intended status: Informational                                  K. Leung
Expires: August 26, 2012                                           Cisco
                                                       February 23, 2012


  CDNI Logging Formats for HTTP and HTTP Adaptive Streaming Deliveries
               draft-lefaucheur-cdni-logging-delivery-00

Abstract

   The interconnection of Content Distribution Networks (CDNs) is
   motivated by several use cases.  CDN Interconnection can be achieved
   through four CDNI interfaces, one of which is the CDNI Logging
   interface.  This document discusses CDNI logging formats for content
   deliveries performed using HTTP or HTTP adaptive streaming.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

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 August 26, 2012.

Copyright Notice

   Copyright (c) 2012 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



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   (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
     1.1.  Terminology  . . . . . . . . . . . . . . . . . . . . . . .  4
   2.  CDNI Logging for regular HTTP Delivery . . . . . . . . . . . .  4
     2.1.  Regular HTTP Log Triggers  . . . . . . . . . . . . . . . .  4
     2.2.  Regular HTTP Log Fields  . . . . . . . . . . . . . . . . .  5
   3.  CDNI Logging for HTTP Adaptive Streaming . . . . . . . . . . .  6
     3.1.  HTTP Adaptive Logging Session  . . . . . . . . . . . . . .  6
     3.2.  CDNI Log formats for HTTP Adaptive Streaming . . . . . . .  7
       3.2.1.  Segment-Based Logging  . . . . . . . . . . . . . . . .  7
       3.2.2.  Event-Based Logging  . . . . . . . . . . . . . . . . .  9
       3.2.3.  Summary-Based Logging  . . . . . . . . . . . . . . . . 10
   4.  Performance Monitoring . . . . . . . . . . . . . . . . . . . . 10
   5.  CDNI Log Encoding and Transport  . . . . . . . . . . . . . . . 11
     5.1.  CDNI Log Header Information  . . . . . . . . . . . . . . . 11
     5.2.  CDNI per-Log-Record Information  . . . . . . . . . . . . . 11
     5.3.  CDNI Log Footer Information  . . . . . . . . . . . . . . . 12
   6.  Impact on CDNI Metadata Requirements . . . . . . . . . . . . . 12
   7.  Generation of CDNI Logs  . . . . . . . . . . . . . . . . . . . 12
   8.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 13
   9.  Security Considerations  . . . . . . . . . . . . . . . . . . . 13
   10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     11.1. Normative References . . . . . . . . . . . . . . . . . . . 13
     11.2. Informative References . . . . . . . . . . . . . . . . . . 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14















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1.  Introduction

   The interconnection of Content Distribution Networks (CDNs) is
   motivated by several use cases, such as those described in
   [I-D.ietf-cdni-use-cases].  The overall problem space for CDN
   Interconnection (CDNI) is described in
   [I-D.ietf-cdni-problem-statement].  The CDN Interconnection framework
   is defined in [I-D.davie-cdni-framework] and the requirements for the
   CDN Interconnection solution are specified in
   [I-D.ietf-cdni-requirements].

   One of the CDNI interfaces defined in these documents is the CDNI
   Logging interface whose description is quoted here:

   "o CDNI Logging interface: This interface allows the Logging system
   in interconnected CDNs to communicate the relevant activity logs in
   order to allow log consuming applications to operate in a multi-CDN
   environments.  For example, an upstream CDN may collect delivery logs
   from a downstream CDN in order to perform consolidated charging of
   the CSP or for settlement purposes across CDNs.  Similarly, an
   upstream CDN may collect delivery logs from a downstream CDN in order
   to provide consolidated reporting and monitoring to the CSP."

   The logging interface is also discussed in further details in
   [I-D.bertrand-cdni-logging].

   As discussed in the CDNI framework [I-D.davie-cdni-framework] logs
   associated with content delivery using HTTP adaptive streaming have
   specific requirements in terms of summarization:

   "Most schemes to deliver HTTP-based adaptive bit-rate video use a
   large number of relatively small HTTP requests (e.g., one request per
   3-second chunk of video.)  It may be desirable to aggregate Logging
   information so that a single log entry is provided for the entire
   video rather than for each chunk.  Note however that such aggregation
   requires a degree of application awareness in dCDN to recognize that
   the many HTTP requests correspond to a single video."

   The prime purpose of this document is to define CDNI Logging formats
   corresponding to content delivery that uses HTTP or HTTP adaptive
   streaming.

   Section 2 discusses the aspect of CDNI Logging that are specific to
   content delivery performed via regular HTTP.  Section 3 discusses the
   aspect of CDNI Logging that are specific to content delivery
   performed via HTTP adaptive streaming.  Section 5 discusses the
   aspect of CDNI Logging that are generic to all the CDNI Logs for
   delivery.



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   CDNI Logging for other events than content delivery (e.g. failures,
   request routing, service monitoring,...) will be discussed in
   subsequent versions.

1.1.  Terminology

   This document uses all terminology defined in
   [I-D.ietf-cdni-problem-statement].  In addition, we introduce the
   following terminology:

   o  HTTP Adaptive Streaming Segment (or Segment): piece of a content
      item that is accessible as a standalone HTTP resource, and thus is
      discreetly accessible via its own Unique Resource Identifier
      (URI).

   o  HTTP Adaptive Streaming Logging Session (or Session): state
      maintained by the delivering CDN allowing association, for logging
      purposes, of the actions (e.g. delivery of Segments) corresponding
      to a given content request by a given End User.  Note that actions
      associated with a given Session may all be performed by a single
      Surrogate of the delivering CDN, or may be performed by different
      Surrogates of the delivering CDN successively (e.g. in case of
      surrogate fail-over) or performed by different Surrogates in
      parallel (e.g. in case of load-balancing of Segments delivery).

   o  Adaptive Streaming Manifest File (or Manifest File): file that
      indicates to the End-User the information (e.g. content
      representations available, rules for mapping between a content
      Segment and its URI) necessary to request the appropriate Segment
      at the appropriate time based on the End-User adaptive logic (e.g.
      increase bitrate, decrease bitrate) and behavior (e.g. seek,
      pause, play).


2.  CDNI Logging for regular HTTP Delivery

   This section discusses the triggers on which a CDNI log is generated
   for delivery of content using regular HTTP delivery, as well as the
   fields contained in the corresponding log.

2.1.  Regular HTTP Log Triggers

   A CDNI Log is generated for a regular HTTP delivery on the following
   triggers:







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   +-----------------+-------------------------------------------------+
   | Event           | Description                                     |
   +-----------------+-------------------------------------------------+
   | content Request | Reception and processing of a request for a     |
   |                 | content                                         |
   +-----------------+-------------------------------------------------+

2.2.  Regular HTTP Log Fields

   A CDNI Log for regular HTTP delivery contains the following fields:

   +---------------+------------+--------------------------------------+
   | Field         | Descriptio | Examples                             |
   |               | n          |                                      |
   +---------------+------------+--------------------------------------+
   | Current-Time  | Time, in   | [20/Feb/2012:00:29.510+0200]         |
   |               | millisecon |                                      |
   |               | ds, at     |                                      |
   |               |  which the |                                      |
   |               |  request   |                                      |
   |               |  was       |                                      |
   |               |  received. |                                      |
   | Time-to-Serve | Time, in   | 952195                               |
   |               | microsecon |                                      |
   |               | ds, taken  |                                      |
   |               |  to        |                                      |
   |               |  complete  |                                      |
   |               |  the       |                                      |
   |               |  request.  |                                      |
   | Client-IP     | IP address | 64.103.25.105                        |
   |               | of the     |                                      |
   |               | requesting |                                      |
   |               | client.    |                                      |
   | Action        | Squid      | TCP_HIT, TCP_MISS, ...               |
   |               | action     |                                      |
   |               | describing |                                      |
   |               | how the    |                                      |
   |               | request    |                                      |
   |               | was        |                                      |
   |               | treated    |                                      |
   |               | locally    |                                      |
   |               | descriptio |                                      |
   |               | n(e.g.,    |                                      |
   |               |  cache     |                                      |
   |               |  hit/miss) |                                      |
   |               | .          |                                      |





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   | Status-Return | HTTP       | 200, 404, ...                        |
   | ed            | response   |                                      |
   |               | code.      |                                      |
   | Bytes-Transfe | Bytes sent | 23567992                             |
   | rred          | to the     |                                      |
   |               | client,    |                                      |
   |               | including  |                                      |
   |               | the        |                                      |
   |               | headers.   |                                      |
   | Method        | HTTP       | GET                                  |
   |               | request    |                                      |
   |               | method.    |                                      |
   | URI           | URI of     | http://cache3.cdn1.com/movie/ice/ice |
   |               | requested  | movie.mpg                            |
   |               | content.   |                                      |
   | Content-Type  | MIME-Type  | video/mpeg                           |
   |               | from the   |                                      |
   |               | reply      |                                      |
   |               | header.    |                                      |
   +---------------+------------+--------------------------------------+


3.  CDNI Logging for HTTP Adaptive Streaming

   This section discusses the CDNI logs for delivery of content using
   HTTP adaptive streaming.

3.1.  HTTP Adaptive Logging Session

   There are multiple methods by which the delivering CDN can create/
   maintain/delete an HTTP Adaptive Streaming Logging Session.

   As a first example method, the delivering CDN may create a Session on
   successful authorization of delivery of the Manifest File for a
   particular End-User content request, create a per-Session coookie and
   then validate the association of Segment requests with the Session
   through HTTP cookie mechanisms.  The delivering CDN may then maintain
   the Session as long as Segment requests are being received for that
   Session.  The delivering CDN may ultimately delete the Session once
   Segment requests for that Session are no longer received for some
   period of time.

   As another example, Session identification information included in
   the fragment URIs may be used by the delivering CDN to associate
   Segment requests with a Session and therefore for determining when a
   Session is to be created/maintained/deleted.

   Methods for tracking HTTP Adaptive Streaming Logging Sessions in a



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   delivering CDN are implementation specific and thus outside the scope
   of the present document.

3.2.  CDNI Log formats for HTTP Adaptive Streaming

   Three CDNI Logging formats are defined for delivery using HTTP
   adaptive streaming:

   o  Segment-Based Logging, as specified in Section 3.2.1.

   o  Event-Based Logging, as specified in Section 3.2.2.

   o  Summary-based Logging, as specified in Section 3.2.3.

   An implementation of the CDNI Logging interface MUST support logging
   for delivery of content using HTTP adaptive streaming in the Segment-
   Based Logging format and the Event-Based Logging format, and MAY
   support logging in the Summary-Based Logging format.

   By default (i.e. unless it is explicitly requested that another
   format be used as discussed in Section 6), CDNI logs for delivery of
   content using HTTP adaptive streaming MUST be formatted as per the
   Event-Based format.

3.2.1.  Segment-Based Logging

3.2.1.1.  Segment-Based Log Triggers

   A Segment-Based Log is generated on the following triggers:

   +---------------------+---------------------------------------------+
   | Event               | Description                                 |
   +---------------------+---------------------------------------------+
   | Segment/Manifest    | Reception of a request for a Segment (or    |
   | Request             | Manifest File)                              |
   +---------------------+---------------------------------------------+

3.2.1.2.  Segment-Based Log fields

   A Segment-based Log for HTTP adaptive streaming contains all the same
   fields as a CDNI Log for a regular HTTP request as well as the
   following additional fields:









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   +-----------------+-------------+-----------------------------------+
   | Field           | Description | Examples                          |
   +-----------------+-------------+-----------------------------------+
   | abr-protocol    | Type of     | hls,hds,hss                       |
   |                 | HTTP        |                                   |
   |                 | adaptive    |                                   |
   |                 | streaming.  |                                   |
   | Session-id      | a string    | 6141F5795BE774691D234A0465B9667A  |
   |                 | generated   |                                   |
   |                 | by the      |                                   |
   |                 | delivering  |                                   |
   |                 | CDN and     |                                   |
   |                 | unique (to  |                                   |
   |                 | the         |                                   |
   |                 | delivering  |                                   |
   |                 | CDN) to     |                                   |
   |                 | identify    |                                   |
   |                 | the         |                                   |
   |                 | Session.    |                                   |
   | Representation  | Characteris | 300000bps                         |
   |                 | tics of the |                                   |
   |                 |  content    |                                   |
   |                 |  representa |                                   |
   |                 | tion (e.g., |                                   |
   |                 |   bitrate). |                                   |
   | manifest-uri    | URI of the  | http://cache3.cdn1.com/movie/ice/ |
   |                 | Manifest    | index300k.m3u8                    |
   |                 | File.       |                                   |
   | content-id      | Identifier  | http://cache3.cdn1.com/movie/ice/ |
   |                 | for the     | index.m3u8                        |
   |                 | content     |                                   |
   |                 | item        |                                   |
   |                 | independent |                                   |
   |                 | ly of its   |                                   |
   |                 |  representa |                                   |
   |                 | tions.      |                                   |
   | Session-trackin | The method  | cookie, uri_query                 |
   | g-method        | used in the |                                   |
   |                 | delivering  |                                   |
   |                 | CDN for     |                                   |
   |                 | tracking of |                                   |
   |                 | the         |                                   |
   |                 | Session.    |                                   |
   +-----------------+-------------+-----------------------------------+







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3.2.2.  Event-Based Logging

3.2.2.1.  Event-Based Log Triggers

   An Event-Based Log is generated on the following triggers:

   +----------------+--------------------------------------------------+
   | Event          | Description                                      |
   +----------------+--------------------------------------------------+
   | Representation | Reception of a request for a Segment whose       |
   | Change/Bitrate | bitrate is higher than the bitrate of the        |
   | Upshift.       | previously requested Segment.                    |
   | Representation | Reception of a request for a Segment whose       |
   | Change/Bitrate | bitrate is lower than the bitrate of the         |
   | Downshift.     | previously requested Segment.                    |
   | Representation | TBD                                              |
   | Change/TBD.    |                                                  |
   | Session Seek.  | Reception of a request for a Segment whose       |
   |                | playtime is not sequentially following the       |
   |                | previously requested Segment.                    |
   | Session Stop.  | Determination by delivering CDN that the         |
   |                | End-User has temporarily stopped requesting      |
   |                | Segments associated with the Session.  This may  |
   |                | be determined using heuristics such as           |
   |                | expiration of a time-out (e.g. of 10 seconds)    |
   |                | after reception of the last Segment request.     |
   | Session Close. | Determination by delivering CDN that the         |
   |                | End-User has definitively stopped requesting     |
   |                | Segments associated with the Session.  This may  |
   |                | be determined using heuristics such as           |
   |                | expiration of a time-out after any End-USer      |
   |                | activity associated with the Session.            |
   +----------------+--------------------------------------------------+

3.2.2.2.  Event-Based Log Fields

   An Event-Based Log for HTTP adaptive streaming contains all the same
   fields as a Segment-Based Log as well as the following additional
   fields:

   +------------+----------------------+-------------------------------+
   | Field      | Description          | Examples                      |
   +------------+----------------------+-------------------------------+
   | event-code | Event that triggered | Representation Change/Bitrate |
   |            | the generation of    | Upshift, Session Seek,        |
   |            | the log              | Session Stop, ...             |
   +------------+----------------------+-------------------------------+




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3.2.3.  Summary-Based Logging

3.2.3.1.  Summary-Based Log Triggers

   A Summary-Based Log is generated on the following triggers:

   +--------------+----------------------------------------------------+
   | Event        | Description                                        |
   +--------------+----------------------------------------------------+
   | Session      | Determination by delivering CDN that the End-User  |
   | Close        | has definitively stopped requesting Segments       |
   |              | associated with the Session.  This may be          |
   |              | determined using heuristics such as expiration of  |
   |              | a time-out after any End-USer activity associated  |
   |              | with the Session.                                  |
   | Intermediate | Expiration of a Logging Period Time-out since a    |
   | Logging      | previous Summary-Based Log was generated for that  |
   | Period       | Session (or since the start of the Session).       |
   +--------------+----------------------------------------------------+

3.2.3.2.  Summary-Based Log Fields

   An Event-Based Log for HTTP adaptive streaming contains all the same
   fields as a Segment-Based Log, minus the Representation field, plus
   the following additional fields:

   [This will be specified in subsequent versions.  The objective is to
   define fields that summarize succinctly -while retaining enough
   information- the fluctuations in content representation (e.g.
   bitrate/quality variations) as well as stop/start/seek patterns over
   the duration of the Session (or over the Intermediate Logging period)
   for the audio and video components. ]


4.  Performance Monitoring

   The CDNI Log fields listed in the previous sections allow monitoring
   of essential delivery performance indicators across the CDN Mesh.
   For example, for a regular HTTP delivery, these fields allow tracking
   of the time taken to serve the requested content, tracking of content
   delivery failures, tracking of partial deliveries and tracking of
   cache hit ratios.  As another example, for HTTP adaptive streaming,
   these fields allow tracking of the presentation (and its fluctuation
   over time) served to the End-User as well as the End-User random
   content access (e.g.  Play/Stop/Seek).

   Subsequent versions of this document will discuss potential
   additional log fields for enhanced performance monitoring.



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5.  CDNI Log Encoding and Transport

   Details for CDNI Log encoding and transport will be specified in
   subsequent versions.  However, Section 5.1 identifies the information
   that is to be included in the header of CDNI Logs, Section 5.2
   identifies information that is to be attached to every CDNI Log
   record and Section 5.3 identifies the information that is to be
   included in the footer of CDNI Logs.

5.1.  CDNI Log Header Information

   The header of CDNI Logs contains the following fields:

   +----------------+-------------------+------------------------------+
   | Field          | Description       | Examples                     |
   +----------------+-------------------+------------------------------+
   | Format-Version | Version of the    | v1.0                         |
   |                | CDNI Log format.  |                              |
   | Log-Type       | The type of CDNI  | Delivery_HTTP,               |
   |                | Log.              | Delivery_Adaptive_Segment,   |
   |                |                   | Delivery_Adaptive_Event      |
   | Log-ID         | Unique identifier |                              |
   |                | for the CDNI Log  |                              |
   |                | (facilitates      |                              |
   |                | detection of      |                              |
   |                | duplicate Logs    |                              |
   |                | and tracking in   |                              |
   |                | case of           |                              |
   |                | aggregation).     |                              |
   | Log-Timestamp  | Time, in          | [20/Feb/2012:00:29.510+0200] |
   |                | milliseconds, the |                              |
   |                | CDNI Log was      |                              |
   |                | generated.        |                              |
   +----------------+-------------------+------------------------------+

5.2.  CDNI per-Log-Record Information

   In addition to the log fields discussed in previous sections, each
   CDNI log record contains the following fields:

   +----------+---------------------------------------------+----------+
   | Field    | Description                                 | Examples |
   +----------+---------------------------------------------+----------+
   | Log      | Digest of the Log records (facilitates      |          |
   | Record   | recovery of uncorrupted Log records inside  |          |
   | Digest   | a corrupted CDNI Log)                       |          |
   +----------+---------------------------------------------+----------+




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5.3.  CDNI Log Footer Information

   The footer of CDNI Logs contains the following fields:

   +---------+----------------------------------------------+----------+
   | Field   | Description                                  | Examples |
   +---------+----------------------------------------------+----------+
   | Log     | Digest of the complete Log (facilitates      |          |
   | Digest  | detection of Log corruption)                 |          |
   +---------+----------------------------------------------+----------+


6.  Impact on CDNI Metadata Requirements

   We request that the following requirement be added in section 6 of
   [I-D.ietf-cdni-requirements]:

   "

   META-X [HIGH] The CDNI Metadata Distribution interface shall support
   an optional mechanism allowing the Upstream CDN to indicate to the
   Downstream CDN which CDNI Log format is to be provided for all, for
   specific sets of, or for specific content items delivered using HTTP
   adaptive streaming.

   ".

   A CDNI implementation that does not support this optional CDNI
   Metadata Distribution Interface mechanism MUST ignore this log format
   indication and generate CDNI logging format for adaptive streaming
   using the default CDNI Logging format for such delivery.


7.  Generation of CDNI Logs

   Like other CDNI interfaces, the CDNI Logging interface specifies
   operations across CDNs and not inside a CDN.  Therefore, the log
   formats specified in this document apply to CDNI logging information
   exchanged across CDNs and does not constrain the process for
   generating such inter-CDN logs within a given CDN.  The format of the
   logs generated by a given CDN Surrogate is beyond the scope of the
   present document.  We observe that a given CDN could elect to have
   its Surrogates natively generate logs in the same format as the one
   to be used for exchange with another CDN, or that the CDN could elect
   to have its Surrogates generate logs in any other format (as long as
   they include the necessary information) and have these logs then
   reformatted prior to exchange with another CDN.




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8.  IANA Considerations

   [This will be specified in subsequent versions].


9.  Security Considerations

   CDNI Logs exchanged over the CDNI Logging interface can be consumed
   by very sensitive applications including inter-CDN accounting and
   billing.  The associated security concerns are discussed in
   [I-D.davie-cdni-framework].  At this stage, we observe that the CDNI
   Logging interface can leverage the existing security mechanisms
   supported by the underlying transport protocol that will be selected
   for transport of CDNI Logs (e.g. to support authentication of the
   entities exchanging CDNI Logs through the CDNI Logging interface, to
   support privacy and protection against spoofing).  This will be
   further discussed in subsequent versions of this document.


10.  Acknowledgements

   The authors want to thank Gene Halbrooks for his input into this
   document.


11.  References

11.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

11.2.  Informative References

   [I-D.bertrand-cdni-logging]
              Gilles, B. and S. Emile, "CDNI Logging Interface",
              draft-bertrand-cdni-logging-00 (work in progress),
              February 2012.

   [I-D.davie-cdni-framework]
              Davie, B. and L. Peterson, "Framework for CDN
              Interconnection", draft-davie-cdni-framework-01 (work in
              progress), October 2011.

   [I-D.ietf-cdni-problem-statement]
              Niven-Jenkins, B., Faucheur, F., and N. Bitar, "Content
              Distribution Network Interconnection (CDNI) Problem
              Statement", draft-ietf-cdni-problem-statement-03 (work in



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              progress), January 2012.

   [I-D.ietf-cdni-requirements]
              Leung, K. and Y. Lee, "Content Distribution Network
              Interconnection (CDNI) Requirements",
              draft-ietf-cdni-requirements-02 (work in progress),
              December 2011.

   [I-D.ietf-cdni-use-cases]
              Gilles, B., Emile, S., Watson, G., Burbridge, T., Eardley,
              P., and K. Ma, "Use Cases for Content Delivery Network
              Interconnection", draft-ietf-cdni-use-cases-03 (work in
              progress), January 2012.


Authors' Addresses

   Francois Le Faucheur
   Cisco Systems
   Greenside, 400 Avenue de Roumanille
   Sophia Antipolis  06410
   France

   Phone: +33 4 97 23 26 19
   Email: flefauch@cisco.com


   Mahesh Viveganandhan
   Cisco Systems
   375 East Tasman Drive
   San Jose  95134
   USA

   Email: mvittal@cisco.com


   Kent Leung
   Cisco Systems
   3625 Cisco Way
   San Jose  95134
   USA

   Phone: +1 408 526 5030
   Email: kleung@cisco.com







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