CLUE                                                      C. Groves, Ed.
Internet-Draft                                                   W. Yang
Intended status: Informational                                   R. Even
Expires: March 19, 2015                                           Huawei
                                                      September 15, 2014


                          CLUE Partial Updates
                  draft-groves-clue-partial-update-00

Abstract

   This document proposes a method for using partial updates in CLUE
   Advertisements to update the CLUE data model.  It uses the XML patch
   operations defined in [RFC5261]

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
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   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 March 19, 2015.

Copyright Notice

   Copyright (c) 2014 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
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   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.




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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Partial Notification Format . . . . . . . . . . . . . . . . .   4
   3.  XML Schema for Partial Negotiations . . . . . . . . . . . . .   5
   4.  Operations  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     4.1.  <add> Element . . . . . . . . . . . . . . . . . . . . . .   7
     4.2.  <replace> Element . . . . . . . . . . . . . . . . . . . .   7
     4.3.  <remove> Element  . . . . . . . . . . . . . . . . . . . .   8
   5.  Error Handling  . . . . . . . . . . . . . . . . . . . . . . .   8
   6.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . . .   8
     6.1.  General . . . . . . . . . . . . . . . . . . . . . . . . .   9
       6.1.1.  Addition  . . . . . . . . . . . . . . . . . . . . . .   9
       6.1.2.  Replacement . . . . . . . . . . . . . . . . . . . . .   9
       6.1.3.  Removal . . . . . . . . . . . . . . . . . . . . . . .   9
     6.2.  Capture Scene <captureScenes> . . . . . . . . . . . . . .   9
       6.2.1.  Addition  . . . . . . . . . . . . . . . . . . . . . .   9
       6.2.2.  Replacement . . . . . . . . . . . . . . . . . . . . .   9
       6.2.3.  Removal . . . . . . . . . . . . . . . . . . . . . . .   9
     6.3.  Media Captures <mediaCaptures>  . . . . . . . . . . . . .  10
       6.3.1.  Addition  . . . . . . . . . . . . . . . . . . . . . .  10
       6.3.2.  Replacement . . . . . . . . . . . . . . . . . . . . .  10
       6.3.3.  Removal . . . . . . . . . . . . . . . . . . . . . . .  10
     6.4.  Encoding Groups <encodingGroups>  . . . . . . . . . . . .  11
       6.4.1.  Addition  . . . . . . . . . . . . . . . . . . . . . .  11
       6.4.2.  Replacement . . . . . . . . . . . . . . . . . . . . .  11
       6.4.3.  Removal . . . . . . . . . . . . . . . . . . . . . . .  11
     6.5.  Simultaneous Sets <simultaneousSets>  . . . . . . . . . .  11
     6.6.  Global Scene Entries <globalSceneEntries> . . . . . . . .  12
     6.7.  People <people> . . . . . . . . . . . . . . . . . . . . .  12
       6.7.1.  Addition  . . . . . . . . . . . . . . . . . . . . . .  12
       6.7.2.  Replacement . . . . . . . . . . . . . . . . . . . . .  12
       6.7.3.  Removal . . . . . . . . . . . . . . . . . . . . . . .  12
   7.  Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .  12
     7.1.  Additional Presentation Capture . . . . . . . . . . . . .  12
     7.2.  Capture Removal . . . . . . . . . . . . . . . . . . . . .  13
     7.3.  Attribute Modification  . . . . . . . . . . . . . . . . .  14
   8.  Summary . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  14
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
   11. Security Considerations . . . . . . . . . . . . . . . . . . .  15
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  15
     12.2.  Informative References . . . . . . . . . . . . . . . . .  15
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15






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1.  Introduction

   As commonly recognised, a large conference using CLUE with many
   participants and captures will result in large CLUE Advertisement
   messages.  Participants may come and go in conferences which require
   updates to the CLUE information.  Sending large CLUE messages to
   remove a single capture or scene results in unnecessary bandwidth and
   processing to compare the existing CLUE description with the updated
   description.  It has been recognised that a method that allows
   partial updates to the CLUE description is desirable.

   This document describes procedures for Partial CLUE Advertisements.
   It does not consider CLUE Configure messages as these are
   significantly smaller than Advertisement messages.

   This document defines a "full Advertisement" as one that does not use
   the partial advertisement syntax and represents a complete
   description of a Media Provider's media sending capabilities at that
   point in time.  A "partial Advertisement" is one that uses the syntax
   defined in this document to represent a sub-set of the complete
   description.

   As noted in clause 4.3/ [I-D.ietf-clue-protocol], an approach using a
   "delta" mechanism for advertising changes is suggested.  It proposed
   to leverage the mechanism defined in [RFC5261].  It effectively
   defines an API for manipulating XML nodes (see clause
   6/[http://www.w3.org/TR/xpath-datamodel/#Node]) in an XML document.
   It utilises XPATH to identify the XML nodes.  A basic tutorial on
   XPATH can be found at: http://www.w3schools.com/XPath/default.asp

   The procedures are based around the use of XPATH path expressions
   (see: clause 3.2/[ http://www.w3.org/TR/xpath20/]) to identify a
   node/s in a CLUE XML document.  Several operations are defined that
   can be used on those nodes.  The "add" operation allows the insertion
   of new XML elements and attributes to the existing XML nodes.  The
   "replace" operation allows the modification of existing XML nodes.
   The "remove" operation allows the removal of existing XML nodes.

   This document is based on updates to version 5 of the CLUE Data Model
   Schema [I-D.ietf-clue-data-model-schema].

   The following functions are defined:

   o  Addition: An add operation issued with new elements has the effect
      of adding the new elements to the CLUEinfo description.






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   o  Replacement: A replacement operation modifies existing element/s
      with the value/s provided.  This may be used to replace child
      elements without requiring separate add and remove operations.

   o  Removal: A removal operation issued on an element has the effect
      of deleting that element and any child elements from the CLUEinfo
      description.

   Partial updates are implemented using the existing CLUE Advertisement
   (ADV) message.  The difference being that the ADV message for partial
   updates will not contain a full clue-info description containing all
   the relevant media provider information but will instead contain a
   partial update syntax.  A Re-Advertisement request (READV/ACK) will
   result in the media provider's full clue-info being sent.  Thus no
   changes to the protocol message state model are envisaged.

   This document does not perform a numerical analysis on how many bytes
   will be saved using an Advertisement with a partial update versus a
   full Advertisement.  The amount of bytes saved will be dependent on
   the desired operation.  The examples in this document show potential
   partial updates against the examples in
   [I-D.ietf-clue-data-model-schema].  The basic example in the data
   model draft is ~6300 characters.  It can be seen that the size of the
   partial updates is considerably less than a full CLUE info
   description.

   This document also does not perform an analysis nor give guidelines
   on how a media provider would determine when to send a partial update
   versus a full update.  It is assumed that the media provider provides
   an initial full clue-info description and that any subsequent
   Advertisements contain partial updates.  A media provider MAY provide
   a full Advertisement at any time.

   Furthermore this document does not describe how the media provider
   determines the "diff" between an old Advertisement and a new one.
   This functionality is internal to the media provider.

2.  Partial Notification Format

   The format of the partial updates in based on the XML scheme "patch-
   ops" defined in [RFC5261].  The partial update XML is defined in a
   new element "clue-info-diff".

   The content of the <clue-info-diff> element is an unordered sequence
   of <add>, <replace>, and <remove> elements followed by elements from
   other namespaces for the purposes of extensibility.  Any such unknown
   elements MUST be ignored by the client.  The <add>, <replace>, and




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   <remove> elements can contain other extension attributes than what
   are defined in the corresponding base types of [RFC6502].

   Author's Note: The introduction of the possibility for extension is
   consistent with [RFC6502].  This aspect may be removed to simplify
   the implementation.

   The elements may appear any number of times and in any order in
   <clue-info-diff>.  However the partial update MUST contain at least
   one <add>, <replace> or <remove> element.  Any changes are with
   respect to the base CLUEinfo description.  The "base" CLUEinfo
   description is the result of a previously sent Advertisement with a
   full CLUEinfo description and any subsequently sent partial updates.
   Then sending of a full CLUEinfo description will have the effect of
   resetting the "base" CLUEinfo description.

   It is not possible for one operation (add/replace/remove) to affect
   another element in the same clue-info-diff.  E.g. an operation may
   not use an XPATH to reference a previous operation in a clue-info-
   diff.  However attribute values may be referenced across operations.
   E.g. a Capture Scene ID may be used to add a capture scene and also
   used in a media capture to reference the scene.

   If the XPATH cannot be resolved to a single node by the receiver an
   error response should be generated.

   Author's Note: XPATH allows quite advanced methods of identifying XML
   nodes.  To simplify implementations it may be advantageous to limit
   the selector values for specifying nodes.  E.g. nodes must be fully
   specified by name rather than using wildcarding.

3.  XML Schema for Partial Negotiations

   This is the XML proposed for inclusion into the CLUE protocol.  It
   includes the schema for XML patching from [RFC5261] (using [RFC6205]
   as the basis for the syntax) and defines the add, remove and
   replacement operations.  It is used in CLUE Advertisement messages.














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   <!-- include patch-ops type definitions -->
       <xs:include
        schemaLocation="urn:ietf:params:xml:schema:patch-ops"/>
       <!-- partial updates -->
       <xs:element name="clue-info-diff">
        <xs:complexType>
         <xs:sequence minOccurs="0" maxOccurs="unbounded">
          <xs:choice>
           <!-- add some content -->
           <xs:element name="add">
            <xs:complexType mixed="true">
             <xs:complexContent>
              <xs:extension base="add">
               <xs:anyAttribute processContents="lax"/>
              </xs:extension>
             </xs:complexContent>
            </xs:complexType>
           </xs:element>
           <!-- remove some content -->
           <xs:element name="remove">
            <xs:complexType>
             <xs:complexContent>
              <xs:extension base="remove">
               <xs:anyAttribute processContents="lax"/>
              </xs:extension>
             </xs:complexContent>
            </xs:complexType>
           </xs:element>
           <!-- replace some content -->
           <xs:element name="replace">
            <xs:complexType mixed="true">
             <xs:complexContent>
              <xs:extension base="replace">
               <xs:anyAttribute processContents="lax"/>
              </xs:extension>
             </xs:complexContent>
            </xs:complexType>
           </xs:element>
           <!-- allow extension elements from other namespaces -->
           <xs:any namespace="##other" processContents="lax"/>
          </xs:choice>
         </xs:sequence>
         <xs:attribute name="entity" type="xs:anyURI" use="required"/>
         <xs:anyAttribute processContents="lax"/>
        </xs:complexType>
       </xs:element>
      </xs:schema>




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   The XML below is also proposed for inclusion into the CLUE protocol.
   It includes the schema for XML patch operation errors from [RFC5261].
   It is used in CLUE Advertisement ACK messages.

   <!-- include patch-ops-error type definitions -->
       <xs:include
        schemaLocation="urn:ietf:params:xml:schema:patch-ops-error"/>
       <!-- partial updates errors -->
       <xs:element name="clue-info-diff-error">
        <xs:complexType>
         <xs:sequence minOccurs="0" maxOccurs="unbounded">
          <xs:choice>
           <!-- add some content -->
           <xs:element name="patch-ops-error">
            <xs:complexType mixed="true">
             <xs:complexContent>
              <xs:extension base="patch-ops-error">
               <xs:anyAttribute processContents="lax"/>
              </xs:extension>
             </xs:complexContent>
            </xs:complexType>
           </xs:element>
         <xs:attribute name="entity" type="xs:anyURI" use="required"/>
         <xs:anyAttribute processContents="lax"/>
        </xs:complexType>
       </xs:element>
      </xs:schema>

4.  Operations

4.1.  <add> Element

   The use of the <add> element is as per section 4.3/[RFC5261] with the
   exception that the addition of attributes and namespaces is not
   supported.  Thus the 'type' attribute is not supported.

   Author's Note: Given the nature of the CLUE XML there doesn't seem to
   be a use case to update namespaces or attributes.

   When inserting elements, the new nodes are described as they should
   appear in the CLUEinfo document with respect to the "sel" and any
   "pos" attribute.

4.2.  <replace> Element

   The use of the <replace> element is as per section 4.4/[RFC5261].





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   When modifying elements the modified nodes must be specified as they
   should appear info the CLUE info document.  The content-to-modify
   must include the element referenced by the xpath and any child
   elements.  It will have the effect of completely replacing the
   previous setting of the element.  Any child element present in the
   base document will be removed if not present in the content-to-
   modify.  Any child element, not present in the base document but
   present in the content-to-modify will be added.  XML attributes
   follow the same behaviour.

4.3.  <remove> Element

   The use of the <remove> element is as per section 4.5/[RFC5261].

5.  Error Handling

   When parsing an Advertisement containing a partial update, the Media
   Consumer may detect an error in the partial update or may not be able
   to unambiguously apply the update.  This may result in an error.  In
   order to support error handling the <patch-ops-error> element should
   be included in the Advertisement Acknowledgement message.

6.  Procedures

   This section describes the rules associated with partial updates to a
   CLUE Advertisement.  Due to the structure of the CLUE data model
   there are dependencies between the different elements in the CLUE
   info document.  These procedures are from a syntactic perspective and
   cover interactions between CLUEinfo elements.  Various combinations
   of operations may or may not make sense from an application
   perspective, however the application perspective is out of scope of
   these procedures.

   Firstly general rules are described that apply to all elements in the
   CLUEInfo.  Procedures specific to the following top level elements
   are then described:

   o  mediaCaptures

   o  encodingGroups

   o  captureScenes

   o  simultaneousSets

   o  globalSceneEntries

   o  people



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6.1.  General

6.1.1.  Addition

   When adding a new element, any mandatory child elements must be
   included.  For example: when adding a new media capture the
   <capturedMedia>, <captureSceneIDREF> and <encGroupIDREF> elements
   must be included in the partial update.

6.1.2.  Replacement

   See the specific procedures for replacement in the clauses below.

6.1.3.  Removal

   The deletion of an element will have the effect of deleting all child
   elements.

6.2.  Capture Scene <captureScenes>

6.2.1.  Addition

   A partial update may add additional <captureScene> elements to the
   <captureScenes> element.  Additional <sceneEntry> elements may be
   added to the <sceneEntries> element.  Additional media captures
   (<captureIDREF>) may be added to the <sceneEntry> element.

6.2.2.  Replacement

   A partial update may modify the child elements of the
   <captureSceneType>.  If the <sceneID> element is changed then any
   elements that reference the sceneID (e.g.  by captureSceneIDREF in
   <mediaCaptureType> element) must also be changed in the partial
   update.

6.2.3.  Removal

   A partial update may remove a capture scene from an existing CLUEInfo
   description.  If the sceneID of the deleted capture scene is used in
   other elements (e.g.  by captureSceneIDREF in <mediaCaptureType>)
   then these elements must either be removed or the captureSceneIDRef
   must be changed to another existing capture scene identity in the
   partial update.

   A partial update may delete a <sceneEntry> element.  If the
   sceneEntryID is used in other elements (e.g. by sceneEntryIDREF in
   <globalCaptureEntryType> and <simultaneousSetType> then these
   elements must either be requested to be removed or the



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   sceneEntryIDREF must be changed to another existing capture scene
   entry identity in the partial update.

6.3.  Media Captures <mediaCaptures>

6.3.1.  Addition

   A partial update may add additional captures may by specifying
   additional <mediaCaptureType> structures.  The partial update must
   include the mandatory elements of the structure.  Therefore the
   <captureSceneIDREF> elements must reference existing Capture Scenes
   or reference Capture Scenes being added in the partial update.

   The addition of a new media capture may also require that the
   captureID is added to elements that reference media captures.  For
   example: captureIDREF in the <contentType> (for multiple content
   captures), mediaCaptureIDs in the <sceneEntryType> element,
   captureIDREF in the <simultaneousSetType> element and IDREF in the
   <relatedTo> element.  The addition of a mediaCapture may also result
   in a new <sceneEntry> element (see clause 3.2.1) and possibily an
   update of the <globalCaptureEntries> element being needed in the
   partial update.

   If the new media capture contains a <capturedPeople> element
   containing <personIDREF> elements, the referenced <personID> must
   also be added to the <people> element if it has previously not been
   included.

   Additional capture attributes may be added to existing media
   captures.

6.3.2.  Replacement

   A partial update may modify the child elements of the
   <mediaCaptureType>.  If the <captureID> element is changed then any
   elements that reference the captureID (e.g.  by captureIDREF) must
   also be changed in the partial update.

   If the partial update modifies the <capturedPeople> element then the
   <people> element may need to be updated.  See clauses 6.3.1 and
   6.3.3.

6.3.3.  Removal

   A partial update may remove a <mediaCapture> element.  The captureID
   of the removed mediaCapture must also be removed from any elements
   that reference the captureID in the partial update.  For example:
   captureIDREF in the <contentType> (for multiple content captures),



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   mediaCaptureIDs in the <sceneEntryType> element, captureIDREF in the
   <simultaneousSetType> element and IDREF in the <relatedTo> element.

   If the removed media capture contains a <capturedPeople> element
   containing <personIDREF> elements and the referenced <personID>s are
   not referenced by any other media capture, the referenced persons may
   removed from the <people> element.

6.4.  Encoding Groups <encodingGroups>

6.4.1.  Addition

   An <encodingGroup> element may be added to without requiring
   modification to other top level elements.  However if the encoding
   group is to be used by media captures, the encGroupIDREF of the added
   encoding group must be added to at least one media capture.  Child
   elements of <encodingGroup> may be added without impact to other top
   level elements.

   Note: The change of an encID may result an SDP Offer/Answer exchange
   modifying an encoding.

6.4.2.  Replacement

   If the <encodingGroupID> attribute is modified then any media
   captures that reference the encodingGroupID (through the
   encGroupIDREF) must also be modified.

   Note: The change of an encID may result an SDP Offer/Answer exchange
   modifying an encoding.

6.4.3.  Removal

   If an encodingGroup element is removed any media captures that
   reference the removed encodingGroup (through the encGroupIDREF
   element) must be modified to reference a new encoding group ID or the
   encoding group must be removed in the partial update.

   Note: The removal of an encID may result an SDP Offer/Answer exchange
   removing an encoding.

6.5.  Simultaneous Sets <simultaneousSets>

   Operations (Add, Replace, Remove) may be applied the
   <simultaneousSets> element without any impacts on other top level
   elements.  Any referenced media captures or capture scene entries
   must exist.




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6.6.  Global Scene Entries <globalSceneEntries>

   Operations (Add, Replace, Remove) may be applied the
   <globalSceneEntries> element without any impacts on other top level
   elements.  Any referenced capture scene entries must exist.

6.7.  People <people>

6.7.1.  Addition

   A new <people> element may be added without affecting other top level
   elements.  However for the new element to be used by the receiver of
   the CLUE description the <personID> of the people defined in that
   element must be referenced by one or more media captures or capture
   scenes.

6.7.2.  Replacement

   If the <personID> element is modified then any media captures that
   reference the participant (through the <capturedPeople> element) must
   also be modified.

6.7.3.  Removal

   If a <person> element or any instances of the <personType> element
   are removed then any media captures that reference the removed people
   (through the <capturedPeople> element) must be modified to remove the
   personID in question.

7.  Examples

   The following examples are based on partial updates to the sample XML
   file in clause 22/[I-D.ietf-clue-data-model-schema].  The changes are
   against the sample XML file.  The changes are not cumulative across
   the examples.

7.1.  Additional Presentation Capture

   A presentation video capture (VC5) is added to the conference for a
   document camera.  As this doesn't share a co-ordinate space a new
   Capture scene (CS2) is added.  The clue-info-diff indicates to add
   the new capture after media capture VC4.  An existing encoding group
   is used.  The new capture is also added to the simultaneous sets SS1
   and SS2 as it may be used in conjunction with the other captures.
   The following shows the additions:






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<clue-info-diff xmlns="urn:ietf:params:xml:ns:clue-info">
  <add sel="clueInfo/captureScenes/captureScene[1]" pos="after">
    <captureScene scale="unknown" sceneID="CS2">
      <sceneEntries>
        <sceneEntry mediaType="video" sceneEntryID="SE5">
          <mediaCaptureIDs>
            <captureIDREF>VC5</captureIDREF>
          </mediaCaptureIDs>
        </sceneEntry>
      </sceneEntries>
    </captureScene>
  </add>
 <add sel="clueInfo/simultaneousSets/simultaneousSet[1]/captureIDREF[1]"
          pos="after">
   <captureIDREF>VC5</captureIDREF>
  </add>
 <add sel="clueInfo/simultaneousSets/simultaneousSet[2]/captureIDREF[4]"
          pos="after">
   <captureIDREF>VC5</captureIDREF>
  </add>
  <add sel="clueInfo/mediaCaptures/mediaCapture[6]" pos="after">
    <mediaCapture xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                      xsi:type="videoCaptureType" captureID="VC5">
      <capturedMedia>video</capturedMedia>
      <captureSceneIDREF>CS2</captureSceneIDREF>
      <encGroupIDREF>EG0</encGroupIDREF>
      <individual>true</individual>
      <description lang="en">document camera</description>
      <presentation>image</presentation>
    </mediaCapture>
  </add>
</clue-info-diff>

7.2.  Capture Removal

   The video captures VC3 and VC4 are no longer available.  As a result
   the following must be removed from the CLUE information:

   o  mediaCaptures for VC3 and VC4

   o  sceneEntries for SE2 and SE3 as they only contain VC3 and VC4

   o  capture identities for VC3 and VC4 from the simultaneousSets

   The following shows the partial update with the removal:






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<clue-info-diff xmlns="urn:ietf:params:xml:ns:clue-info">
  <remove sel="clueInfo/mediaCaptures/mediaCapture[5]">
  <remove sel="clueInfo/mediaCaptures/mediaCapture[6]">
  <remove sel="clueInfo/captureScene/sceneEntries/sceneEntry[2]">
  <remove sel="clueInfo/captureScene/sceneEntries/sceneEntry[3]">
  <remove
    sel="clueInfo/simultaneousSets/simultaneousSet[1]/captureIDREF[1]">
  <remove
    sel= "clueInfo/simultaneousSets/simultaneousSet[2]/captureIDREF[3]">
  <remove
    sel="clueInfo/simultaneousSets/simultaneousSet[2]/captureIDREF[4]">
</clue-info-diff>

7.3.  Attribute Modification

   The video capture VC4 zooms in on a particular participant and no
   longer represents a zoomed out view.  As a result the description of
   VC4 and the participants are changed.

   The following shows the partial update with the change:

<clue-info-diff xmlns="urn:ietf:params:xml:ns:clue-info">
  <replace sel="clueInfo/mediaCaptures/mediaCapture[6]/description">
    <description lang="en">zoomed in view on ciccio</description>
  </replace>
  <replace sel= "clueInfo/mediaCaptures/mediaCapture[6]/capturedPeople">
     <capturedPeople>
       <personIDREF>ciccio</participantIDREF>
     </capturedPeople>
  </replace>
</clue-info-diff>

8.  Summary

   The authors believe that the use of partial updates is an efficient
   way of updating CLUE information minimising the amount of data that
   needs to be sent in an Advertisement.  It is proposed to introduce
   partial Advertisements into the CLUE protocol.

9.  Acknowledgements

   This template was derived from an initial version written by Pekka
   Savola and contributed by him to the xml2rfc project.








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10.  IANA Considerations

   It is not expected that the proposed changes present the need for any
   IANA registrations.

11.  Security Considerations

   It is not expected that the proposed changes present any addition
   security issues to the current framework.

12.  References

12.1.  Normative References

   [I-D.ietf-clue-data-model-schema]
              Presta, R. and S. Romano, "An XML Schema for the CLUE data
              model", draft-ietf-clue-data-model-schema-06 (work in
              progress), June 2014.

   [I-D.ietf-clue-protocol]
              Presta, R. and S. Romano, "CLUE protocol", draft-ietf-
              clue-protocol-01 (work in progress), June 2014.

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

   [RFC5261]  Urpalainen, J., "An Extensible Markup Language (XML) Patch
              Operations Framework Utilizing XML Path Language (XPath)
              Selectors", RFC 5261, September 2008.

   [RFC6502]  Camarillo, G., Srinivasan, S., Even, R., and J.
              Urpalainen, "Conference Event Package Data Format
              Extension for Centralized Conferencing (XCON)", RFC 6502,
              March 2012.

12.2.  Informative References

   [RFC2629]  Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
              June 1999.

Authors' Addresses

   Christian Groves (editor)
   Huawei
   Melbourne
   Australia

   Email: Christian.Groves@nteczone.com



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   Weiwei Yang
   Huawei
   P.R.China

   Email: tommy@huawei.com


   Roni Even
   Huawei
   Tel Aviv
   Isreal

   Email: roni.even@mail01.huawei.com






































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