Patent Publication Number: US-8972594-B2

Title: Media mix wiring protocol for media control

Description:
BACKGROUND 
     As more conferencing systems begin to offer one or more streams of the same media type (e.g., video), conferencing clients need to be capable of rendering more than one stream as offered by the conferencing systems in an inter-operable manner. Mechanisms such as grouping of SDP (session description protocol, as described in RFC 4566) media lines and SDP media content further help in achieving this goal. However, unless a conferencing client understands the context of how these streams ought to be rendered, the conferencing clients may not be able to render streams of which the client not aware. 
     Conventional multipoint control unit (MCU) architecture lack of an efficient, flexible protocol to modify the media mix in the mixer of the MCU such that entities can transmit media as specified or receive media as specified over time. One working group is working on solving the above deficiency by controlling the functions of a mixer (e.g., “play a prompt”, “expect DTMF”, “play this media”, etc.). However, the attempts to control or imitate functions of the mixer are then limited to the available functionality. 
     SUMMARY 
     The following presents a simplified summary in order to provide a basic understanding of some novel embodiments described herein. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
     The disclosed architecture provides an efficient and flexible protocol for wiring media streams and specifying mixing behavior in the multipoint control unit (MCU). Accordingly, entities can transmit media as specified or receive media as specified over time. The protocol provides the capability to expose the core algorithm to modification for mixing media without dealing with the functionality of the mixer itself. 
     The protocol facilitates media wiring by specifying: a means for uniquely identifying a media stream sent to an entity or received from an entity; a means for an entity to wire a media stream coming from the mixer to contain a mix of other specified streams that have been sent to the mixer (by other identities) without having to deal with ports and other IP-specifics; a means for an entity to wire a media stream sent to the mixer to appear in specific streams sent from the mixer (sent to other identities); a means to communicate the wiring of the various media streams to participants allowed to view the wiring based on local policy of the mixer; and, a means where the conference leader can change the main participant mix to include a stream from another entity (participant), and all participants in the conference can perceive the identity of the other entity. 
     To the accomplishment of the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles disclosed herein can be employed and is intended to include all such aspects and equivalents. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a computer-implemented media control system for modifying mixing algorithm behavior. 
         FIG. 2  illustrates a media system where a media control unit includes a media mixer component for mixing input streams based on changes to core mixing algorithms. 
         FIG. 3  illustrates an alternative system for modifying mixing algorithm behavior. 
         FIG. 4  illustrates the exemplary mixer for wiring input streams to output streams at the mixing algorithm level. 
         FIG. 5  illustrates an exemplary schema definition for a protocol that can access and modify mixing behavior at the core mixing algorithms. 
         FIG. 6  illustrates a method of managing media streams. 
         FIG. 7  illustrates a method of manipulating core mixing algorithms of a media mixer to rewire session media streams. 
         FIG. 8  illustrates a method of manipulating core mixing algorithms of a media mixer to rewire session media streams. 
         FIG. 9  illustrates a block diagram of a computing system operable to execute media stream wiring at the core mixing algorithm level in accordance with the disclosed protocol architecture. 
         FIG. 10  illustrates a schematic block diagram of an exemplary client-server computing environment for accessing core mixing algorithms using an access protocol. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed architecture provides a protocol for accessing and manipulating the core mixing algorithms of media mixers, for example, a multipoint control unit (MCU). This also applies to a client-based implementation, rather than network-based implementations, where the user can manipulate the core mixing of audio and video at the client level. 
     Reference is now made to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. It may be evident, however, that the novel embodiments can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate a description thereof. 
       FIG. 1  illustrates a computer-implemented media control system  100  for modifying mixing algorithm behavior. The system  100  includes one or more mixing algorithms  102  of a media mixer  104  for mixing input media streams  106  according to one or more mixing behaviors  108 . The mixer  104  is a logical entity receives the set of media streams of the same type (e.g., audio), combines the media in a type-specific manner, and redistributes the result to a single output or multiple outputs (e.g., session participant(s)). The system  100  also includes a protocol interface  110  that includes one or more instructions  112  for modifying the mixing behavior  108  of the mixing algorithm(s)  102  to wire the input media streams  106  to produce one or more specific output media streams  114 . 
     The one or more instructions  112  of the protocol interface  110  facilitate modification of the mixing algorithms  102  to effect the mixing behavior(s)  108  to uniquely identify a media stream sent to an entity or to uniquely identify a media stream received from the entity, to wire the input media streams to the media mixer into the specific output stream exclusive of mixer port or IP management functions, and to expose wiring information to an entity based on a policy. The policy can be an enterprise policy created and imposed by an administrator, for example. 
     The one or more instructions  112  of the protocol interface  110  also facilitate changing in participation of a session by participants by deleting at least one of many main participants from the session or adding a new participant to the session. The protocol interface  110  includes one or more instructions  112  for notifying the main participants of the change in participation to the session. For example, if main participants A, B and C are in a conference, and participant A has requested to view participant B&#39;s video stream, participant C is not allowed to know that participant A is watching participant B. However, participant B can be allowed to know that participant A is watching participant B&#39;s media stream. The protocol interface  110  includes one or more instructions  112  for adding an input media stream of a new participant to the session and for presenting entity information of the new participant to the main participants. 
     In one implementation, the protocol interface  110  includes a new set of instructions for interacting with the mixing algorithms  102  to generate the mixing behavior(s)  108 . In an alternative implementation, the one or more instructions  112  include extensions to the existing set of controls for generate the mixing behavior(s)  108 . The new set of instructions and/or the control extensions are based on a schema that includes one or more schema elements of route, wire, and filter. 
       FIG. 2  illustrates a media system  200  where a media control unit  202  includes a media mixer component  204  for mixing input streams based on changes to core mixing algorithms. Here, the media mixer component  204  includes two mixers: a first mixer  206  for receiving a first type of input media stream(s)  208  (e.g., audio) for wiring (or routing) to an output media stream  210  of the same type, and a second mixer  212  for receiving a second type of input media stream(s)  214  (e.g., video) for wiring (or routing) to an output media stream  216  of the same type. The first media mixer  206  includes a first mixing algorithm  218  for generating a first mixing behavior  220 . 
     A user can manipulate the first mixing algorithm  218  to change the first mixing behavior  220  via the protocol interface  110  when communicating one or more of the instructions  112  to the first mixing algorithm  218  of the first media mixer  206 . Similarly, the second media mixer  212  includes a second mixing algorithm  222  for generating a second mixing behavior  224 . The user can manipulate the second mixing algorithm  222  to change the second mixing behavior  224  via the protocol interface  110  when communicating one or more of the instructions  112  to the second mixing algorithm  222  of the second media mixer  212 . 
     The one or more instructions  112  facilitate modification of the mixing algorithms  102  to wire the input streams ( 208  and  214 ) as desired. The one or more instructions  112  manage the mixing behavior(s) ( 220  and  224 ) to uniquely identify a media stream sent to an entity or to uniquely identify a media stream received from the entity, to wire the input media streams to the media mixer into the specific output stream exclusive of mixer port or IP management functions, and to expose wiring information to an entity based on a policy. 
     The system  200  facilitates wiring of a single input stream (e.g., of stream(s)  208  and  214 ) from point to point, from point to multiple points, multiple points to multiple points, and from multiple points to a single point. The system  200  can be employed as a network node (e.g., a server) and/or as a client on a client computing system, for example. 
       FIG. 3  illustrates an alternative system  300  for modifying mixing algorithm behavior. The system  300  includes a media control unit  302  having a media mixer  304  from receiving an input media stream  306 , and routing the input stream  306  to an output media stream  308  in accordance with modified mixing behaviors. More specifically, the media mixer  304  includes an audio mixing algorithm  310  for mixing audio into the input stream  306 , and a video mixing algorithm  312  for mixing video into the input media stream  306 . The media mixer  304  includes the protocol interface  110  for processing the protocol instructions  112  from a management interface  314 . In other words, a user can interact via the management interface  314  to send one or more instructions  112  via the protocol interface  110  to modify the core audio mixing algorithm  310  and/or the core video mixing algorithm  312 . 
     The mixing algorithms ( 310  and  312 ) generate mixing behaviors that are processed by a routing component  316  for routing the input media stream  306  to the output media stream  308 . The routing component  316  receives and processes an audio mixing behavior  318  generated from the audio mixing algorithm  310  and a video mixing behavior  320  from the video mixing algorithm  312 . In other words, the input media stream  306  can be mixed with audio and/or video signals for routing as a mixed output media stream  308  to an output entity. 
     A policy component  322  receives and processes one or more policies that can regulate how the mixing is to be done and if the mixing will be performed based on the receiving entity, source users, etc. The policy component  322  can include a session policy server that governs the operation of the session. 
       FIG. 4  illustrates the exemplary mixer  104  for wiring input streams to output streams at the mixing algorithm level. The mixer  104  receives input (or to-mixer) media streams  400 , and mixes the input streams  400  according to the video mixing algorithm  310  and the audio mixing algorithm  320  to produce output (or from-mixer) media streams  402 . Modification of the mixing algorithms ( 310  and  320 ) can occur via the protocol interface  110 . 
     The input streams  400  can be identified with identity information for the user and the type of media stream, for example, a user identity (userID=xx) and a media stream identity (ID=xx). In this example, input media stream types ID=30, ID=31, and ID=32 and userID=2 can be for a second session participant&#39;s (or endpoint) main audio stream, main video stream, and secondary video stream, respectively. Similarly, input media stream types ID=24 and ID=31 are associated with userID=3 for a third session participant&#39;s (or endpoint) main audio stream and main video stream, respectively. Other input streams  400  can be part of the conference session. 
     A “label” parameter identifies the media stream to and from the mixer  104 . As indicated previously, the input streams  400  to the mixer  104  (from a specific user and endpoint) are identified by an ID in the conferencing data model. The label is unique throughout the conferencing data model. The ID is unique within the endpoint media element in the data model and is generated by the conferencing server. 
     Consider that the label=10 is the stream containing the audio stream mix from all audio input streams offered to every session participant, label=11 includes a video mix, and that label=12 is an alternate mix of the video streams that is voice activated. The mixer  104  mixes the incoming video streams  400  from the participants into both the label=11 and label=12 output streams. This is one example of a mixer model; other mixer models can interpret the input streams differently. However, the introduction of the protocol interface  110  facilitates modification of the mixing algorithms in accordance with the disclosed architecture. The protocol interface  110  can receive change or modifications to the mixing algorithms ( 310  and  320 ) via XML, for example, and/or CCCP (centralized conference control protocol) commands. 
       FIG. 5  illustrates an exemplary schema definition  500  for a protocol that can access and modify mixing behavior at the core mixing algorithms. The schema definition  500  can be as follows. In one implementation, the schema defines new controls extensions (e.g., route, wire and filter) from controls that are defined in a centralized conferencing (XCON) data model. The newly-added elements to the schema definition  500  are referenced in the following tree view with a “##” and circumscribed as  502  for the input to the mixer and  504  as the output of the mixer. 
     
       
         
           
               
             
               
                   
               
             
            
               
                 !&lt;conference-info&gt; 
               
            
           
           
               
               
            
               
                   
                  | 
               
               
                   
                  |--!&lt;users&gt; 
               
            
           
           
               
               
               
            
               
                   
                  | 
                 |--. . . 
               
               
                   
                  | 
                 | 
               
               
                   
                  | 
                 |--!&lt;user&gt; 
               
            
           
           
               
               
               
               
            
               
                   
                  | 
                 | 
                 |--. . . . 
               
               
                   
                  | 
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                 |--. . . . 
               
               
                   
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                 | 
               
               
                   
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                 |--!&lt;endpoint&gt; 
               
            
           
           
               
               
               
               
               
            
               
                   
                  | 
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                 |--. . . . 
               
               
                   
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                 |--. . . . 
               
               
                   
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                 |--!&lt;media&gt; 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                  | 
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                 |--&lt;type&gt; 
               
               
                   
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                 |--&lt;display-text&gt; 
               
               
                   
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                 |--&lt;label&gt; 
               
               
                   
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                 |--&lt;src-id&gt; 
               
               
                   
                  | 
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                 |--&lt;status&gt; 
               
               
                   
                  | 
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                 |--&lt;to-mixer&gt;* 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                  | 
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                 |--&lt;floor&gt;* 
               
               
                   
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                 |--&lt;controls&gt;* 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                  | 
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                 |--&lt;route&gt;## 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                  | 
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                 |--&lt;wire&gt;## 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
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                 |--&lt;filter&gt;## 
               
               
                   
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                 ... 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                  | 
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                 |--&lt;from-mixer&gt;* 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
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                 |--&lt;floor&gt;* 
               
               
                   
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                 |--&lt;controls&gt;* 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
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                 |--&lt;route&gt;## 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
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                 |--&lt;wire&gt;## 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
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                 |--&lt;filter&gt;## 
               
               
                   
                   
               
            
           
         
       
     
     Following are a series of examples that illustrate ways in which the protocol architecture facilitates media wiring. The data contained within such a schema is shown in the following example. Consider a conference session with the media state as follows for a conference sip:conf233@example.com hosted on the MCU https://Mcu55.company.com:444/MCU. 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 &lt;users&gt; 
               
               
                   
                  &lt;user entity=”sip:foo@example.com”&gt; 
               
               
                   
                   &lt;endpoint entity=”sip:foo@example.com;gr=14837492”&gt; 
               
               
                   
                    &lt;media id=”12”&gt; 
               
               
                   
                     &lt;!-this is the default stream for foo@example.com- 
               
               
                   
                 -&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;1111&lt;/label&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                    &lt;media id=”34”&gt; 
               
               
                   
                     &lt;!-this is the stream where foo@example.com wants 
               
               
                   
                 to manipulate the mixing routes--&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;recvonly&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;abcd123&lt;/label&gt; 
               
               
                   
                     &lt;!-Note: No media routes defined here→ 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/endpoint&gt; 
               
               
                   
                  &lt;/user&gt; 
               
               
                   
                  &lt;user entity=”sip:bar1@contoso.com”&gt; 
               
               
                   
                   &lt;endpoint entity=”sip:bar1@contoso.com;gr=14837492”&gt; 
               
               
                   
                    &lt;media id=”56”&gt; 
               
               
                   
                     &lt;!-this is the default stream for foo@example.com- 
               
               
                   
                 -&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;efgh123&lt;/label&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/endpoint&gt; 
               
               
                   
                  &lt;/user&gt; 
               
               
                   
                  &lt;user entity=”sip:bar2@fabrikam.com”&gt; 
               
               
                   
                   &lt;endpoint entity=”sip:bar2@fabrikam.com;gr=67432333”&gt; 
               
               
                   
                    &lt;media id=”78”&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;ijkl456&lt;/label&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/endpoint&gt; 
               
               
                   
                  &lt;/user&gt; 
               
               
                   
                 &lt;/users&gt; 
               
               
                   
                   
               
            
           
         
       
     
     Following is an example of CCCP command(s) for modifying the media route for a participant. Consider that the entity sip:foo@example.com wants to modify the media route based on the stream. The entity may do so by issuing the following CCCP command “modifyEndpointMedia”. The following example shows a request that foo@example.com is making to receive streams from bar1@contoso.com and bar2@fabrikam.com. (The XMLNS specification is omitted for readability.) 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                  &lt;request 
               
               
                   
                   requestId=″1″ 
               
               
                   
                   from=″client″ 
               
               
                   
                   to=″MCU− 
               
               
                   
                   (xmlns spec was here) 
               
               
                   
                   &lt;modifyEndpointMedia&gt; 
               
               
                   
                   &lt;endpointKeys 
               
               
                   
                     confEntity=″sip:conf233@example.com″ 
               
               
                   
                     userEntity=″sip:foo@example.com″ 
               
               
                   
                     endpointEntity=″sip:foo@example.com;gr=14837492″/&gt; 
               
               
                   
                    &lt;media id=″34″ 
               
               
                   
                     xmlns=″urn:ietf:params:xml:ns:conference-info″&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;recvonly&lt;/status&gt; 
               
               
                   
                      &lt;label&gt;abcd123&lt;/label&gt; 
               
               
                   
                      &lt;from-mixer&gt; 
               
               
                   
                       &lt;controls&gt; 
               
               
                   
                        &lt;!-Note: Modified routing table→ 
               
               
                   
                        &lt;route&gt; 
               
               
                   
                         &lt;wire user- 
               
               
                   
                 entity=”sip:bar1@contoso.com” endpoint- 
               
               
                   
                 entity=”sip:bar1@contoso.com;gr=4940254792” label=″efgh123″&gt; 
               
               
                   
                          &lt;filter&gt;dtmf&lt;/filter&gt; 
               
               
                   
                         &lt;/wire&gt; 
               
               
                   
                         &lt;wire user- 
               
               
                   
                 entity=”sip:bar2@fabrikam.com” endpoint- 
               
               
                   
                 entity=”sip:bar2@fabrikam.com;gr=67432333″ label=″ijkl456”&gt; 
               
               
                   
                          &lt;filter&gt;dtmf&lt;/filter&gt; 
               
               
                   
                         &lt;/wire&gt; 
               
               
                   
                        &lt;/route&gt; 
               
               
                   
                       &lt;/controls&gt; 
               
               
                   
                      &lt;/from-mixer&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/modifyEndpointMedia&gt; 
               
               
                   
                  &lt;/request&gt; 
               
               
                   
                   
               
            
           
         
       
     
     The response can be as follows: 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 &lt;response 
               
               
                   
                  requestId=“1” 
               
               
                   
                  from= “MCU” 
               
               
                   
                  to= “Client” 
               
               
                   
                  code=“success” 
               
               
                   
                  (xmlns spec was here) 
               
               
                   
                  &lt;modifyEndpointMedia/&gt; 
               
               
                   
                 &lt;/response&gt; 
               
               
                   
                   
               
            
           
         
       
     
     The new state of the conference session (a media route for a participant) can be communicated to other participants in the conference using the state notification as shown below or can be polled using a new CCCP command. Following is an example of a notification option. 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 &lt;users&gt; 
               
               
                   
                  &lt;user entity=”sip:foo@example.com”&gt; 
               
               
                   
                   &lt;endpoint entity=”sip:foo@example.com;gr=14837492”&gt; 
               
               
                   
                    &lt;media id=”12”&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;1111&lt;/label&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                    &lt;media id=”34”&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;recvonly&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;abcd123&lt;/label&gt; 
               
               
                   
                     &lt;from-mixer&gt; 
               
               
                   
                      &lt;controls&gt; 
               
               
                   
                       &lt;!-Note: Modified routing 
               
               
                   
                 table in C3P notification→ 
               
               
                   
                       &lt;route&gt; 
               
               
                   
                        &lt;wire user- 
               
               
                   
                 entity=”sip:bar1@contoso.com” endpoint- 
               
               
                   
                 entity=”sip:bar1@contoso.com;gr=4940254792” label=”efgh123”&gt; 
               
               
                   
                  &lt;filter&gt;dtmf&lt;/filter&gt; 
               
               
                   
                        &lt;/wire&gt; 
               
               
                   
                        &lt;wire user- 
               
               
                   
                 entity=”sip:bar2@fabrikam.com” endpoint- 
               
               
                   
                 entity=”sip:bar2@fabrikam.com;gr=67432333” label=”ijkl456”&gt; 
               
               
                   
                  &lt;filter&gt;dtmf&lt;/filter&gt; 
               
               
                   
                        &lt;/wire&gt; 
               
               
                   
                       &lt;/route&gt; 
               
               
                   
                      &lt;/controls&gt; 
               
               
                   
                     &lt;/from-mixer&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/endpoint&gt; 
               
               
                   
                  &lt;/user&gt; 
               
               
                   
                  &lt;user entity=”sip:bar1@contoso.com”&gt; 
               
               
                   
                   &lt;endpoint entity=”sip:bar1@contoso.com;gr=14837492”&gt; 
               
               
                   
                    &lt;media id=”56”&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;efgh123&lt;/label&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/endpoint&gt; 
               
               
                   
                  &lt;/user&gt; 
               
               
                   
                  &lt;user entity=” sip:bar2@fabrikam.com”&gt; 
               
               
                   
                   &lt;endpoint entity=”sip:bar2@fabrikam.com;gr=67432333”&gt; 
               
               
                   
                    &lt;media id=”78”&gt; 
               
               
                   
                     &lt;type&gt;audio&lt;/type&gt; 
               
               
                   
                     &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                   
                     &lt;label&gt;ijkl456&lt;/label&gt; 
               
               
                   
                    &lt;/media&gt; 
               
               
                   
                   &lt;/endpoint&gt; 
               
               
                   
                  &lt;/user&gt; 
               
               
                   
                 &lt;/users&gt; 
               
               
                   
                   
               
            
           
         
       
     
     With respect to the polling-option, if there are size considerations with the previous notification-option and/or there is no capability for the system to filter out elements that require privacy functions, a polling mechanism can be used to retrieve the wire route. The mechanism returns a list of users and endpoints (session participants) that are watching a specific endpoint stream. The example below illustrates a command that can be used to retrieve media watcher state for bar1@contoso.com and endpoint sip:bar1@contoso.com;gr=4940254792 with media id=56. Since foo@example.com is the only entity watching the stream, that user entity and endpoint information is returned. 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 &lt;request 
               
               
                   
                  requestId=“1” 
               
               
                   
                  from=“Client” 
               
               
                   
                  to=“MCU” 
               
               
                   
                  (xmlns spec was here) 
               
               
                   
                  &lt;getMediaWatchers&gt; 
               
               
                   
                   &lt;endpointKeys 
               
               
                   
                    confEntity=“sip:conf233@example.com” 
               
               
                   
                    userEntity=“sip:bar1@contoso.com” 
               
               
                   
                   endpointEntity=sip:bar1@contoso.com;gr=4940254792/&gt; 
               
               
                   
                  &lt;/getMediaWatchers&gt; 
               
               
                   
                 &lt;/request&gt; 
               
               
                   
                   
               
            
           
         
       
     
     The response can be as follows: 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                  &lt;response 
               
               
                   
                   requestId=″1″ 
               
               
                   
                   from= ″MCU″ 
               
               
                   
                   to= ″Client″ 
               
               
                   
                   code=″success″ 
               
               
                   
                   &lt;getMediaWatchers&gt; 
               
               
                   
                    &lt;users&gt; 
               
               
                   
                     &lt;user entity=”sip:foo@example.com”&gt; 
               
               
                   
                      &lt;endpoint 
               
               
                   
                 entity=”sip:foo@example.com;gr=14837492”/&gt; 
               
               
                   
                     &lt;!-Note: There are no other XML elements returned 
               
               
                   
                 under endpoint or user or users. --&gt; 
               
               
                   
                     &lt;/user&gt; 
               
               
                   
                    &lt;/users&gt; 
               
               
                   
                   &lt;/getMediaWatchers&gt; 
               
               
                   
                   &lt;/response&gt; 
               
               
                   
                   
               
            
           
         
       
     
     Following is exemplary CCCP command for modifying the main media route effecting the session mix of participants. 
     
       
         
           
               
             
               
                   
               
             
            
               
                   &lt;request 
               
               
                   requestId=″1″ 
               
               
                   from=″Client″ 
               
               
                   to=″MCU″ 
               
               
                   (xmlns spec was here) 
               
               
                   &lt;modifyEntityState&gt; 
               
               
                    &lt;entityKeys 
               
               
                     confEntity=sip:conf233@example.com 
               
               
                     entityView=″sip:srivats@microsoft.com;gruu;opaque=app:conf: 
               
               
                     audio-video:id:f63ad350e41f46798244bda6630db317″ 
               
               
                     /&gt; 
               
               
                    &lt;media label=″main-video″ 
               
               
                     xmlns=″urn:ietf:params:xml:ns:conference-info″&gt; 
               
               
                       &lt;from-mixer&gt; 
               
               
                        &lt;controls&gt; 
               
               
                         &lt;!-Note: Modified routing table→ 
               
               
                         &lt;route&gt; 
               
               
                          &lt;wire user- 
               
               
                 entity=”sip:bar1@contoso.com” endpoint- 
               
               
                 entity=”sip:bar1@contoso.com;gr=4940254792” label=”efgh123”&gt; 
               
               
                           &lt;filter&gt;dtmf&lt;/filter&gt; 
               
               
                          &lt;/wire&gt; 
               
               
                         &lt;/route&gt; 
               
               
                        &lt;/controls&gt; 
               
               
                       &lt;/from-mixer&gt; 
               
               
                    &lt;/media&gt; 
               
               
                   &lt;/modifyEntityState&gt; 
               
               
                 &lt;/request&gt; 
               
               
                   
               
            
           
         
       
     
     The response can be as follows: 
     
       
         
           
               
               
             
               
                   
                   
               
             
            
               
                   
                 &lt;response 
               
               
                   
                  requestId=“1” 
               
               
                   
                  from= “MCU” 
               
               
                   
                  to= “Client” 
               
               
                   
                  code=“success” 
               
               
                   
                  (xmlns spec was here) 
               
               
                   
                  &lt;modifyEntityState/&gt; 
               
               
                   
                 &lt;/response&gt; 
               
               
                   
                   
               
            
           
         
       
     
     Following is an example of notification of the main media route. The new state of the conference can be communicated to other participants in the conference session using the state notification as shown below. 
     
       
         
           
               
             
               
                   
               
             
            
               
                 &lt;msci:entity-view ci:state=″full″ 
               
               
                 entity=″sip:srivats@microsoft.com;gruu;opaque=app:conf:audio- 
               
               
                 video:id:f63ad350e41f46798244bda6630db317″&gt; 
               
               
                   &lt;msci:entity-capabilities&gt; 
               
               
                    &lt;msav:capabilities&gt; 
               
               
                     &lt;msav:supports-audio&gt;false&lt;/msav:supports-audio&gt; 
               
               
                     &lt;msav:supports-video&gt;true&lt;/msav:supports-video&gt; 
               
               
                    &lt;/msav:capabilities&gt; 
               
               
                   &lt;/msci:entity-capabilities&gt; 
               
               
                   &lt;msci:entity-state&gt; 
               
               
                    &lt;msci:media&gt; 
               
               
                     &lt;entry label=″main-video″&gt; 
               
               
                      &lt;type&gt;video&lt;/type&gt; 
               
               
                      &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                      &lt;msci:modal-parameters&gt; 
               
               
                       &lt;msci:video-parameters&gt; 
               
               
                        &lt;msav:video-mode&gt;dominant-speaker- 
               
               
                       switched&lt;/msav:video-mode&gt; 
               
               
                       &lt;/msci:video-parameters&gt; 
               
               
                      &lt;/msci:modal-parameters&gt; 
               
               
                      &lt;controls&gt; 
               
               
                       &lt;route&gt; 
               
               
                        &lt;wire user-entity=”sip:bar1@contoso.com” endpoint- 
               
               
                        entity=”sip:bar1@contoso.com;gr=4940254792” 
               
               
                        label=”efgh123”&gt; 
               
               
                         &lt;filter/&gt; 
               
               
                        &lt;/wire&gt; 
               
               
                       &lt;/route&gt; 
               
               
                      &lt;/controls&gt; 
               
               
                     &lt;/entry&gt; 
               
               
                     &lt;entry label=″panoramic-video″&gt; 
               
               
                      &lt;type&gt;panoramic-video&lt;/type&gt; 
               
               
                      &lt;status&gt;sendrecv&lt;/status&gt; 
               
               
                     &lt;/entry&gt; 
               
               
                    &lt;/msci:media&gt; 
               
               
                   &lt;/msci:entity-state&gt; 
               
               
                 &lt;/msci:entity-view&gt; 
               
               
                   
               
            
           
         
       
     
     With respect to privacy concerns, the protocol instructions can communicate how the media is wired to other participants in the conference based on local policy. Local conference server policy can be taken into consideration whether the participant receiving this information is authorized to receive the wired media or not. 
     To accommodate the notification option, the Notifier (defined in RFC 3265 and RFC 4353 as a user agent that generates Notify requests for the purpose of notifying subscribers of the state of a resource) filters certain elements based on where the notification is being sent. If there are no privacy considerations, the Notifier can send this information to all participants or may choose to not send the information at all. 
     Following is a series of flow charts representative of exemplary methodologies for performing novel aspects of the disclosed architecture. While, for purposes of simplicity of explanation, the one or more methodologies shown herein, for example, in the form of a flow chart or flow diagram, are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation. 
       FIG. 6  illustrates a method of managing media streams. At  600 , an input media stream of a conferencing session is wired to an endpoint according to a mixing behavior defined by a mixing algorithm. At  602 , the mixing algorithm is accessed using a protocol of instructions. At  604 , the mixing algorithm is changed using the protocol to rewire the input media stream according to a new mixing behavior. 
       FIG. 7  illustrates a method of manipulating core mixing algorithms of a media mixer to rewire session media streams. At  700 , the core mixing algorithm(s) can be accessed using a protocol. At  702 , the input stream sent to an endpoint or received from an endpoint can be uniquely identified using the protocol. At  704 , optionally, specify rewiring of the input media stream of an endpoint at an output to include a mix of other input streams by other endpoints exclusive of functions related to ports and IP data using the protocol. At  706 , optionally, specify wiring of the input media stream of an endpoint to specific output media streams of corresponding endpoints using the protocol. 
       FIG. 8  illustrates a method of manipulating core mixing algorithms of a media mixer to rewire session media streams. At  800 , the core mixing algorithm(s) can be accessed using a protocol. At  802 , communication of the wiring to session participants is specified using the protocol. At  804 , communication of the wiring is specified to session participants using the protocol and based on a session policy. At  806 , a change in participant mix of the conferencing session by a session leader is specified using the protocol. 
     As used in this application, the terms “component” and “system” are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, a hard disk drive, multiple storage drives (of optical and/or magnetic storage medium), an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed between two or more computers. 
     Referring now to  FIG. 9 , there is illustrated a block diagram of a computing system  900  operable to execute media stream wiring at the core mixing algorithm level in accordance with the disclosed protocol architecture. In order to provide additional context for various aspects thereof,  FIG. 9  and the following discussion are intended to provide a brief, general description of a suitable computing system  900  in which the various aspects can be implemented. While the description above is in the general context of computer-executable instructions that may run on one or more computers, those skilled in the art will recognize that a novel embodiment also can be implemented in combination with other program modules and/or as a combination of hardware and software. 
     Generally, program modules include routines, programs, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the inventive methods can be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, minicomputers, mainframe computers, as well as personal computers, hand-held computing devices, microprocessor-based or programmable consumer electronics, and the like, each of which can be operatively coupled to one or more associated devices. 
     The illustrated aspects can also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices. 
     A computer typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by the computer and includes volatile and non-volatile media, removable and non-removable media. By way of example, and not limitation, computer-readable media can comprise computer storage media and communication media. Computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital video disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer. 
     With reference again to  FIG. 9 , the exemplary computing system  900  for implementing various aspects includes a computer  902  having a processing unit  904 , a system memory  906  and a system bus  908 . The system bus  908  provides an interface for system components including, but not limited to, the system memory  906  to the processing unit  904 . The processing unit  904  can be any of various commercially available processors. Dual microprocessors and other multi-processor architectures may also be employed as the processing unit  904 . 
     The system bus  908  can be any of several types of bus structure that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. The system memory  906  can include non-volatile memory (NON-VOL)  910  and/or volatile memory  912  (e.g., random access memory (RAM)). A basic input/output system (BIOS) can be stored in the non-volatile memory  910  (e.g., ROM, EPROM, EEPROM, etc.), which BIOS are the basic routines that help to transfer information between elements within the computer  902 , such as during start-up. The volatile memory  912  can also include a high-speed RAM such as static RAM for caching data. 
     The computer  902  further includes an internal hard disk drive (HDD)  914  (e.g., EIDE, SATA), which internal HDD  914  may also be configured for external use in a suitable chassis, a magnetic floppy disk drive (FDD)  916 , (e.g., to read from or write to a removable diskette  918 ) and an optical disk drive  920 , (e.g., reading a CD-ROM disk  922  or, to read from or write to other high capacity optical media such as a DVD). The HDD  914 , FDD  916  and optical disk drive  920  can be connected to the system bus  908  by a HDD interface  924 , an FDD interface  926  and an optical drive interface  928 , respectively. The HDD interface  924  for external drive implementations can include at least one or both of Universal Serial Bus (USB) and IEEE 1394 interface technologies. 
     The drives and associated computer-readable media provide nonvolatile storage of data, data structures, computer-executable instructions, and so forth. For the computer  902 , the drives and media accommodate the storage of any data in a suitable digital format. Although the description of computer-readable media above refers to a HDD, a removable magnetic diskette (e.g., FDD), and a removable optical media such as a CD or DVD, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as zip drives, magnetic cassettes, flash memory cards, cartridges, and the like, may also be used in the exemplary operating environment, and further, that any such media may contain computer-executable instructions for performing novel methods of the disclosed architecture. 
     A number of program modules can be stored in the drives and volatile memory  912 , including an operating system  930 , one or more application programs  932 , other program modules  934 , and program data  936 . The one or more application programs  932 , other program modules  934 , and program data  936  can include the mixing algorithms  102 , media mixer  104 , input media streams  106 , mixing behaviors  108 , protocol interface  110 , protocol instructions  112 , output media streams  114 , audio mixing algorithm  310 , video mixing algorithm  320 , input media streams  400  output media streams  402 , and the schema  500 , for example. 
     All or portions of the operating system, applications, modules, and/or data can also be cached in the volatile memory  912 . It is to be appreciated that the disclosed architecture can be implemented with various commercially available operating systems or combinations of operating systems. 
     A user can enter commands and information into the computer  902  through one or more wire/wireless input devices, for example, a keyboard  938  and a pointing device, such as a mouse  940 . Other input devices (not shown) may include a microphone, an IR remote control, a joystick, a game pad, a stylus pen, touch screen, or the like. These and other input devices are often connected to the processing unit  904  through an input device interface  942  that is coupled to the system bus  908 , but can be connected by other interfaces such as a parallel port, IEEE 1394 serial port, a game port, a USB port, an IR interface, etc. 
     A monitor  944  or other type of display device is also connected to the system bus  908  via an interface, such as a video adaptor  946 . In addition to the monitor  944 , a computer typically includes other peripheral output devices (not shown), such as speakers, printers, etc. 
     The computer  902  may operate in a networked environment using logical connections via wire and/or wireless communications to one or more remote computers, such as a remote computer(s)  948 . The remote computer(s)  948  can be a workstation, a server computer, a router, a personal computer, portable computer, microprocessor-based entertainment appliance, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer  902 , although, for purposes of brevity, only a memory/storage device  950  is illustrated. The logical connections depicted include wire/wireless connectivity to a local area network (LAN)  952  and/or larger networks, for example, a wide area network (WAN)  954 . Such LAN and WAN networking environments are commonplace in offices and companies, and facilitate enterprise-wide computer networks, such as intranets, all of which may connect to a global communications network, for example, the Internet. 
     When used in a LAN networking environment, the computer  902  is connected to the LAN  952  through a wire and/or wireless communication network interface or adaptor  956 . The adaptor  956  can facilitate wire and/or wireless communications to the LAN  952 , which may also include a wireless access point disposed thereon for communicating with the wireless functionality of the adaptor  956 . 
     When used in a WAN networking environment, the computer  902  can include a modem  958 , or is connected to a communications server on the WAN  954 , or has other means for establishing communications over the WAN  954 , such as by way of the Internet. The modem  958 , which can be internal or external and a wire and/or wireless device, is connected to the system bus  908  via the input device interface  942 . In a networked environment, program modules depicted relative to the computer  902 , or portions thereof, can be stored in the remote memory/storage device  950 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers can be used. 
     The computer  902  is operable to communicate with wire and wireless devices or entities using the IEEE 802 family of standards, such as wireless devices operatively disposed in wireless communication (e.g., IEEE 802.11 over-the-air modulation techniques) with, for example, a printer, scanner, desktop and/or portable computer, personal digital assistant (PDA), communications satellite, any piece of equipment or location associated with a wirelessly detectable tag (e.g., a kiosk, news stand, restroom), and telephone. This includes at least Wi-Fi (or Wireless Fidelity), WiMax, and Bluetooth™ wireless technologies. Thus, the communication can be a predefined structure as with a conventional network or simply an ad hoc communication between at least two devices. Wi-Fi networks use radio technologies called IEEE 802.11x (a, b, g, etc.) to provide secure, reliable, fast wireless connectivity. A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wire networks (which use IEEE 802.3-related media and functions). 
     Referring now to  FIG. 10 , there is illustrated a schematic block diagram of an exemplary client-server computing environment  1000  for accessing core mixing algorithms using an access protocol. The environment  1000  includes one or more client(s)  1002 . The client(s)  1002  can be hardware and/or software (e.g., threads, processes, computing devices). The client(s)  1002  can house cookie(s) and/or associated contextual information, for example. 
     The environment  1000  also includes one or more server(s)  1004 . The server(s)  1004  can also be hardware and/or software (e.g., threads, processes, computing devices). The servers  1004  can house threads to perform transformations by employing the architecture, for example. One possible communication between a client  1002  and a server  1004  can be in the form of a data packet adapted to be transmitted between two or more computer processes. The data packet may include a cookie and/or associated contextual information, for example. The environment  1000  includes a communication framework  1006  (e.g., a global communication network such as the Internet) that can be employed to facilitate communications between the client(s)  1002  and the server(s)  1004 . 
     Communications can be facilitated via a wire (including optical fiber) and/or wireless technology. The client(s)  1002  are operatively connected to one or more client data store(s)  1008  that can be employed to store information local to the client(s)  1002  (e.g., cookie(s) and/or associated contextual information). Similarly, the server(s)  1004  are operatively connected to one or more server data store(s)  1010  that can be employed to store information local to the servers  1004 . 
     The server(s)  1004  can include the mixing algorithms  102 , media mixer  104 , input media streams  106 , mixing behaviors  108 , protocol interface  110 , protocol instructions  112 , output media streams  114 , media control unit  202 , media mixer component  204 , media mixers ( 206  and  212 ), mixing algorithms ( 218  and  222 ) and corresponding mixing behaviors ( 220  and  224 ), audio mixing algorithm  310 , video mixing algorithm  320 , input media streams  400  output media streams  402 , and the schema  500 , for example. The clients(s)  1002  can also include some or all of the entities described for the server(s)  1004 , except the MCU, which is typically a network-based entity. 
     What has been described above includes examples of the disclosed architecture. It is, of course, not possible to describe every conceivable combination of components and/or methodologies, but one of ordinary skill in the art may recognize that many further combinations and permutations are possible. Accordingly, the novel architecture is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim.