REALTIME KERNEL

• US 20100146085A1
• Filed: 12/04/2009
• Published: 06/10/2010
• Est. Priority Date: 12/05/2008
• Status: Active Grant

• Current Assignee: Sococo, Inc.
• Original Assignee: Social Communications Company
• Inventors: Van Wie, David, Altmaier, Joseph
• Granted Patent: US 8,578,000 B2
• Time in Patent Office: Days
• US Class Current: 709/220
• CPC Class Codes: A63F 13/12 involving interaction between a plurality of game devices, e.g. transmisison or distribution systems protocols for networked virtual reality, networked games H04L29/06034
• CPC Class Codes: A63F 13/30 Interconnection arrangements between game servers and game devices; Interconnection arrangements between game devices; Interconnection arrangements between game servers
• CPC Class Codes: G06F 3/165 Management of the audio stream, e.g. setting of volume, audio stream path
• CPC Class Codes: H04L 12/00 Data switching networks interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F13/00
• CPC Class Codes: H04L 65/00 Network arrangements, protocols or services for supporting real-time applications in data packet communication real-time or near real-time messaging, e.g. instant messaging [IM] H04L51/04; selective video distribution H04N21/00
• CPC Class Codes: H04L 65/403 Arrangements for multi-party communication, e.g. for conferences data switching systems for conference H04L12/18; arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities H04M3/56; television conferencing systems H04N7/15
• CPC Class Codes: H04L 65/60 Network streaming of media packets
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04L 67/1059 Inter-group management mechanisms, e.g. splitting, merging or interconnection of groups
• CPC Class Codes: H04L 67/131 Protocols for games, networked simulations or virtual reality
• CPC Class Codes: H04L 67/141 Setup of application sessions admission control or resource allocation in data switching networks H04L47/70
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04N 21/00 Selective content distribution, e.g. interactive television or video on demand [VOD] real-time bi-directional transmission of motion video data H04N7/14 ; broadcast or conference over packet switching networks H04L12/18

Abstract

A realtime kernel supports realtime communications between communicants operating on respective network nodes. The realtime kernel handles the complex tasks of connecting to communicants, virtual areas, and other network resources, switching those connections in response to user inputs, and mixing realtime data streams. The realtime kernel enables developers to focus on developing high-level communications functionality instead of low-level plumbing code. The realtime kernel imposes relatively low computational resource requirements so that realtime communications performance can be achieved using a wide range of computing devices and network connections that currently are available.

Claims

1. A computer-implemented method of remote-controlled realtime data stream handling, comprising:

at a local network node, receiving one or more stream handling instructions from a remote network node, wherein the one or more stream handling instructions comprise a specification of a stream handler for processing at least one realtime data stream;

at the local network node, creating a stream handler in accordance with the specification; and

producing a resultant data stream at the local network node, wherein the producing comprises processing a realtime data stream through the created stream handler.

2. The method of claim 1, wherein the producing comprises

determining configuration parameter values from realtime state information specified in the one or more stream handling instructions, and

dynamically configuring the stream handler with the configuration parameter values.

3. The method of claim 1, wherein the creating comprises building the stream handler with a mixing function that is specified in the one or more stream handling instructions, and the producing comprises mixing the realtime data stream with at least one other realtime data stream in accordance with the mixing function to produce a mixed realtime data stream.

4. The method of claim 1, wherein:

the creating comprises instantiating processing objects specified in the one or more stream handling instructions and assembling the instantiated processing objects into a directed graph component of the stream handler in accordance with the specification; and

the processing comprises processing the realtime data stream through the directed graph.

5. The method of claim 4, wherein the producing comprises

determining configuration parameter values for the instantiated processing objects from realtime state information specified in the one or more stream handling instructions, and

configuring the processing objects with the configuration parameter values.

6. The method of claim 4, wherein the instantiating comprises instantiating a mixing object specified in the one or more stream handling instructions, and the producing comprises executing the mixing object to produce a mixed realtime data stream from a combination of the realtime data stream and at least one other realtime data stream.

7. The method of claim 4, wherein at least one of the instantiated processing objects encapsulates a respective call to a driver module controlling a hardware component of the local network node based at least in part on the resultant data stream.

8. The method of claim 4, wherein the one or more stream handling instructions specify the processing objects with respective unique identifiers and the instantiating comprises issuing to a processing object application program interface procedure (API) calls comprising respective ones of the identifiers.

9. The method of claim 1, wherein the one or more stream handling instructions comprise a second specification of a second stream handler for processing at least one realtime data stream of a data type different that the first realtime data stream, the creating comprises creating a second stream handler in accordance with the second specification, and the producing comprises processing a realtime data stream through the second stream handler.

10. The method of claim 1, wherein the local network node is associated with a first object in a virtual area, and further comprising receiving the realtime data stream from a second remote network node that is associated with a second object in the virtual area.

11. The method of claim 10, wherein the one or more stream handling instructions comprise realtime position information describing the respective positions of the first and second objects in the virtual area, and the producing comprises determining configuration parameter values from the realtime position information and configuring the stream handler with the configuration parameter values.

12. The method of claim 11, further comprising receiving a second realtime data stream from a third remote network node that is associated with a third object in the virtual area, wherein the creating comprises building the stream handler with a mixing function specified in the one or more stream handling instructions, and the producing comprises combining the first realtime data stream and the second realtime data stream in accordance with the mixing function.

13. The method of claim 11,

wherein the one or more stream handling instructions comprise a second specification of a second stream handler for processing at least one realtime data stream of a data type different than the first realtime data stream,

further comprising receiving a second realtime data stream from the third remote network node, and

wherein the creating comprises creating a second stream handler in accordance with the second specification, and the producing comprises configuring the second stream handler in accordance with one or more of the configuration parameter values and processing the first realtime data stream and the second realtime data stream through the second stream handler.

14. The method of claim 10, wherein:

the one or more stream handling instructions comprise realtime position information describing the respective positions of the first and second objects in the virtual area;

the creating comprises building the stream handler with one or more object attribute processing functions that are specified in the one or more stream handling instructions;

the producing comprises determining object configuration parameter values from the realtime position information, and dynamically configuring the one or more object attribute processing functions with the object configuration parameter values while producing the resultant data stream; and

the generating comprises rendering a visible output comprising visual representations of the first and second objects in the virtual area based at least in part on the resultant data stream.

15. The method of claim 14, wherein at least one of the one or more object attribute processing functions is configured to dynamically control the visual representation of the first object in terms of at least one of orientation, position, movement, and pose based on the position of the first object in the virtual area.

16. The method of claim 1, wherein the specified data type is audio and the generating comprises generating an audible output.

17. The method of claim 16, wherein the creating comprises building the stream handler with one or more audio processing functions that are specified in the one or more stream handling instructions.

18. The method of claim 17, wherein the network node is associated with a first object in a virtual area, further comprising receiving the realtime data stream from a second network node that is associated with a second object in the virtual area, and wherein the one or more stream handling instructions comprise realtime position information describing the respective positions of the first and second objects in the virtual area, and the producing comprises determining audio processing configuration parameter values from the realtime position information and configuring the stream handler with the audio processing configuration parameter values.

19. The method of claim 16, wherein the creating comprises building the stream handler with a mixing function that is specified in the one or more stream handling instructions, and the producing comprises combining the realtime data stream with at least one other realtime audio data stream in accordance with the mixing function.

20. The method of claim 1, further comprising at the local network node:

storing remote publish definitions received from the remote network node, wherein the definitions describe realtime data streams available from one or more remote network nodes;

storing local subscription definitions of realtime data streams requested by local realtime kernel components of the local network node; and

sending to one or more of the remote network nodes respective realtime data stream requests for each of the local subscribe definitions having a matching remote publish definition.

21. The method of claim 20, further comprising at the local network node directing realtime data streams received from the one or more remote network nodes in response to the requests to respective ones of the local realtime kernel components in accordance with the local subscribe definitions.

22. The method of claim 1, further comprising generating a human-perceptible output at the local network node based at least in part on the resultant data stream.

23. Apparatus, comprising:

a computer-readable medium storing computer-readable instructions; and

a data processing unit coupled to the memory, operable to execute the instructions, and based at least in part on the execution of the instructions operable to perform operations comprising

at a local network node, receiving one or more stream handling instructions from a remote network node, wherein the one or more stream handling instructions comprise a specification of a stream handler for processing at least one realtime data stream,

at the local network node, creating a stream handler in accordance with the specification, and

producing a resultant data stream at the local network node, wherein the producing comprises processing a realtime data stream through the created stream handler.

24. At least one computer-readable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed by a computer to implement a method comprising:

at a local network node, receiving one or more stream handling instructions from a remote network node, wherein the one or more stream handling instructions comprise a specification of a stream handler for processing at least one realtime data stream;

at the local network node, creating a stream handler in accordance with the specification; and

producing a resultant data stream at the local network node, wherein the producing comprises processing a realtime data stream through the created stream handler.

25. A computer-implemented method of realtime data stream handling, comprising:

parsing a specification of a realtime stream handler from one or more stream handling instructions, wherein the parsing comprises parsing an input source identifier, an output sink identifier, and a respective identifier of each of one or more data processing objects from the one or more stream handing instructions;

instantiating realtime stream handling objects corresponding to respective ones of the identifiers;

creating a directed graph comprising ones of the instantiated realtime stream handling objects in accordance with the specification;

receiving a realtime data stream from an input source corresponding to the input source identifier; and

producing a resultant data stream at an output sink corresponding to the output sink identifier, wherein the producing comprises processing the realtime data stream through the directed graph.

26. The method of claim 25, wherein the parsing comprises extracting identifiers of data processing objects from the one or more stream handling instructions, and the creating comprises assembling the directed graph from instantiations of realtime stream handling objects corresponding to the extracted identifiers.

27. The method of claim 25, wherein the parsing comprises extracting identifiers of audio processing objects from the one or more stream handling instructions, and the processing comprises processing the realtime data stream through one or more instantiated audio processing objects corresponding to respective ones of the extracted identifiers.

28. The method of claim 25, wherein the instantiating comprises querying an object library for the respective identifiers, retrieving objects from the object library in response to the querying, and instantiating the retrieved objects.

29. The method of claim 28, wherein the instantiating comprises issuing to a processing object application program interface (API) procedure calls comprising respective ones of the identifiers.

30. The method of claim 25, wherein the producing comprises

determining configuration parameter values from realtime state information specified in one or more of the stream handling instructions, and

dynamically configuring one or more of the instantiated realtime stream handling objects in the directed graph with the configuration parameter values.

31. The method of claim 25, wherein:

the receiving comprises receiving a second realtime data stream from a second input source corresponding to a second input source identifier in the specification; and

the producing comprises processing the second realtime data stream through the directed graph.

32. The method of claim 31, wherein the instantiating comprises instantiating a realtime stream mixing object corresponding to a respective one of the parsed identifiers, the creating comprises incorporating the instantiated realtime stream mixing object into the directed graph, and the producing comprises executing the instantiated realtime stream mixing object to combine the first realtime data stream and the second realtime data stream.

33. The method of claim 32, wherein the first input source corresponds to a definition of an incoming realtime data stream from a first remote network node, and the second input source corresponds to a definition of an incoming realtime data stream from a second remote network node.

34. The method of claim 25, wherein:

the parsing comprises parsing a second specification of a second realtime stream handler from the one or more stream handling instructions, the second specification comprising a second input source identifier, a second output sink identifier, and a respective identifier of each of one or more data processing objects;

the creating comprises creating a second directed graph from ones of the instantiated realtime stream handling objects in accordance with the second specification;

the receiving comprises receiving a second realtime data stream from a second input source corresponding to the second input source identifier, wherein the first and second realtime data streams are deferent in terms of data type; and

the producing comprises processing the second realtime data stream through the second directed graph to a second output sink corresponding to the second output sink identifier.

35. The method of claim 34, wherein the first realtime data stream and the second realtime data stream are processed concurrently.

36. The method of claim 25, wherein at least one of the instantiated realtime stream handling objects encapsulates a respective call to a driver module controlling a local hardware component.

37. The method of claim 25, wherein the parsing, the instantiating, the creating, the receiving, the producing, and the generating are performed on a local network node that is associated with a first object in a virtual area, and the receiving comprises receiving the realtime data stream from a remote network node that is associated with a second object in the virtual area.

38. The method of claim 37, wherein the one or more stream handling instructions comprise realtime position information describing the respective positions of the first and second objects in the virtual area, and the producing comprises determining configuration parameter values from the realtime position information and dynamically configuring one or more of the instantiated realtime stream handling objects in the directed graph with the configuration parameter values.

39. The method of claim 38, wherein the receiving comprises receiving a second realtime data stream from a second remote network node that is associated with a third object in the virtual area, the creating comprises building the directed graph with an instantiated mixing object corresponding to a respective one of the parsed identifiers, and the producing comprises executing the instantiated mixing object to combine the first realtime data stream and the second realtime data stream.

40. The method of claim 38, wherein:

the parsing comprises parsing a second specification of a second realtime stream handler from the one or more stream handling instructions, the second specification comprising a second input source identifier, a second output sink identifier, and a respective identifier of each of one or more data processing objects;

the creating comprises creating a second directed graph from ones of the instantiated realtime stream handling objects in accordance with the second specification;

the receiving comprises receiving a second realtime data stream from a second input source corresponding to the second input source identifier, wherein the second input source corresponds to a definition of an incoming realtime data stream from a second remote network node and the first and second realtime data streams are different in terms of data type; and

the producing comprises processing the second realtime data stream through the second directed graph to a second output sink corresponding to the second output sink identifier.

41. The method of claim 38, wherein:

the parsing comprises extracting identifiers of graphic object appearance processing objects from the one or more stream handling instructions; and

the producing comprises processing the realtime data stream through one or more instantiated graphic object appearance processing objects corresponding to respective ones of the extracted identifiers, and dynamically configuring the instantiated graphic object appearance processing objects to control a visual representation of the first object in terms of at least one of orientation, position, movement, and pose based at least in part on the position of the first object in the virtual area.

42. The method of claim 25, wherein the parsing, the instantiating, the creating, the receiving, the producing, and the generating are performed on a remote network node, and further comprising associating interface elements of a user-level application executing on a local network node with the realtime data stream, and transmitting the realtime data stream from the local network node to the remote network node.

43. The method of claim 42, further comprising transmitting the one or more stream handing instructions from the local network node to the remote network node.

44. The method of claim 43, wherein the user-level application is a desktop application program.

45. The method of claim 44, wherein the user-level application is a Microsoft Office®

desktop application program.

46. The method of claim 25, wherein the stream handling instructions specify the realtime stream handler without reference to function.

47. The method of claim 25, wherein the stream handling instructions specify the realtime stream handler without reference to stream type.

48. The method of claim 25, wherein the producing comprises traversing the directed graph from the output sink to the input source during each of successive fixed length intervals.

49. The method of claim 25, wherein the parsing comprises parsing one or more records each of which comprises a respective definition type, a respective definition length, and at least one of a definition-type-specific field and a respective definition-type-specific definition.

50. The method of claim 25, further comprising generating a human-perceptible output based at least in part on the resultant data stream.

51. Apparatus, comprising:

a computer-readable medium storing computer-readable instructions; and

a data processing unit coupled to the memory, operable to execute the instructions, and based at least in part on the execution of the instructions operable to perform operations comprising

parsing a specification of a realtime stream handler from one or more stream handling instructions, wherein the parsing comprises parsing an input source identifier, an output sink identifier, and a respective identifier of each of one or more data processing objects from the one or more stream handing instructions,

instantiating realtime stream handling objects corresponding to respective ones of the identifiers,

creating a directed graph comprising ones of the instantiated realtime stream handling objects in accordance with the specification,

receiving a realtime data stream from an input source corresponding to the input source identifier, and

producing a resultant data stream at an output sink corresponding to the output sink identifier, wherein the producing comprises processing the realtime data stream through the directed graph.

52. At least one computer-readable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed by a computer to implement a method comprising:

parsing a specification of a realtime stream handler from one or more stream handling instructions, wherein the parsing comprises parsing an input source identifier, an output sink identifier, and a respective identifier of each of one or more data processing objects from the one or more stream handing instructions;

instantiating realtime stream handling objects corresponding to respective ones of the identifiers;

creating a directed graph comprising ones of the instantiated realtime stream handling objects in accordance with the specification;

receiving a realtime data stream from an input source corresponding to the input source identifier; and

producing a resultant data stream at an output sink corresponding to the output sink identifier, wherein the producing comprises processing the realtime data stream through the directed graph.

53. A computer-implemented method of realtime data stream handling, comprising:

establishing at least one realtime data stream connection between a local network node and at least one remote network node;

at the local network node, processing at least one realtime data stream sourced by the remote network node, wherein the processing comprises processing the at least one realtime data stream through one or more realtime data processing operations to produce a resultant data stream;

monitoring the processing; and

in response to a determination based on the monitoring that the processing deviates from a performance target, modifying the processing in accordance with a realtime performance targeting routine.

54. The method of claim 53, wherein the modifying comprises omitting the processing of one or more portions of the realtime data stream in response to a determination that the processing fails to satisfy the performance target.

55. The method of claim 53, wherein the modifying comprises omitting one or more of the realtime data processing operations in response to a determination that the processing fails to satisfy the performance target.

56. The method of claim 55, wherein the omitting comprises omitting one or more of the data processing operations characterized by respective performance values that are outside the performance target.

57. The method of claim 55, wherein ones of the data processing operations are assigned respective priority values, and the omitting comprises preferentially omitting one or more of the data processing operations based on the assigned priority values.

58. The method of claim 53, wherein the modifying comprises replacing at least one of the realtime data processing operations with a different respective realtime data processing operation in response to a determination that the processing fails to satisfy the performance target.

59. The method of claim 53, wherein one or more of the realtime data processing operations are assigned respective priority values, the realtime performance targeting routine comprises a heuristic that determines ones of the data processing operations to omit based on the assigned priority values, and the modifying is performed in accordance with the heuristic.

60. The method of claim 59, wherein the heuristic determines ones of the data processing operations to omit based on a weighting of the assigned priority values by a time-based performance statistic.

61. The method of claim 53, wherein the modifying comprises iteratively modifying the processing until the processing is within the specified performance target.

62. The method of claim 53, wherein the processing comprises:

instantiating processing objects ones of which are operable to perform respective ones of the data processing operations;

building a directed graph from ones of the instantiated processing objects; and

processing the realtime data stream through the directed graph.

63. The method of claim 62, wherein the modifying comprises pruning one or more of the instantiated processing objects from the directed graph.

64. The method of claim 63, wherein ones of the processing objects are assigned respective priority values, and the pruning comprises removing ones of the instantiated processing objects from the directed graph based on the assigned priority values.

65. The method of claim 64, wherein the pruning comprises removing from the directed graph ones of the instantiated processing objects assigned respective priority values that fail to satisfy a priority threshold.

66. The method of claim 62, wherein the processing comprises building a second directed graph from ones of the instantiated processing objects, and processing through the second directed graph a second realtime data stream sourced by one of the local network node and the at least one remote network node.

67. The method of claim 66, wherein the first and second directed graphs are assigned respective priority values, and the modifying comprises preferentially modifying one of the first and second directed graphs based on the assigned priority values.

68. The method of claim 67, wherein the modifying comprises omitting the processing of the one of the first and second realtime data streams through the respective one of the first and second directed graphs assigned a lowest priority value.

69. The method of claim 62, wherein the processing comprises processing through the directed graph a second realtime data stream sourced by one of the local network node and the at least one remote network node.

70. The method of claim 69, wherein the first and second realtime data streams are assigned respective priority values, and the modifying comprises preferentially modifying the processing of one of the first and second realtime data streams based on the assigned priority values.

71. The method of claim 62, wherein the establishing comprises establishing respective realtime data stream connections between the local network node and multiple remote network nodes, and the processing comprises processing through the directed graph realtime data streams sourced by respective ones of the remote network nodes.

72. The method of claim 71, wherein the realtime data streams are assigned respective priority values, and the modifying comprises preferentially modifying the processing of one or more of the realtime data streams based on the assigned priority values.

73. The method of claim 71, wherein the directed graph comprises multiple directed chains of respective ones of the instantiated processing objects, and the processing comprises processing through each of the directed chains a respective one of the realtime data streams each of which is sourced by a respective one of the local network node and the remote network nodes.

74. The method of claim 73, wherein the modifying comprises iteratively modifying the processing until the processing is within the specified performance target, and during each iteration the modifying comprises performing one or more of (i) removing one or more of the chains from the directed graph and (ii) pruning one or more of the instantiated processing objects from the directed graph.

75. The method of claim 53, wherein the performance target comprises a time-based threshold on production of the resultant data stream.

76. The method of claim 53, further comprising at the local network node receiving from a remote network node one or more stream handing instructions comprising assignments of respective priority values to the one or more realtime data processing operations, wherein the modifying comprises modifying the processing based on the assigned priority values.

77. The method of claim 53, wherein the modifying comprises reducing a computational resource load to a lower level in response to a determination that the processing fails to satisfy the performance target.

78. The method of claim 77, wherein the modifying comprises increasing the computational resource load from the lower level in response to a determination that the processing satisfies the performance target.

79. The method of claim 53, wherein the realtime data stream is packetized into frames, and the monitoring is performed on each of each of the frames.

80. The method of claim 79, wherein the processing comprises processing the frames of the realtime data stream during each of successive fixed length intervals that are set in accordance with a local clock.

81. The method of claim 80, further comprising at the local network node, synchronizing the local clock with a remote master clock service.

82. The method of claim 53, wherein the monitoring comprises monitoring utilization of at least one processor of the local network node.

83. The method of claim 53, wherein the monitoring comprises monitoring bandwidth utilization by at least one networking resource of the local network node.

84. The method of claim 53, further comprising, at the local network node, generating a human-perceptible output responsive to the resultant data stream.

85. The method of claim 84, wherein the local network node and the remote network node are associated with respective objects in a virtual area, and the human-perceptible output is a visualization of the objects in the virtual area on a display.

86. Apparatus, comprising:

a computer-readable medium storing computer-readable instructions; and

a data processing unit coupled to the memory, operable to execute the instructions, and based at least in part on the execution of the instructions operable to perform operations comprising

establishing at least one realtime data stream connection between a local network node and at least one remote network node,

at the local network node, processing at least one realtime data stream sourced by the remote network node, wherein the processing comprises processing the at least one realtime data stream through one or more realtime data processing operations to produce a resultant data stream;

monitoring the processing, and

in response to a determination based on the monitoring that the processing deviates from a performance target, modifying the processing in accordance with a realtime performance targeting routine.

87. At least one computer-readable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed by a computer to implement a method comprising:

establishing at least one realtime data stream connection between a local network node and at least one remote network node;

at the local network node, processing at least one realtime data stream sourced by the remote network node, wherein the processing comprises processing the at least one realtime data stream through one or more realtime data processing operations to produce a resultant data stream;

monitoring the processing; and

in response to a determination based on the monitoring that the processing deviates from a performance target, modifying the processing in accordance with a realtime performance targeting routine.

88. A computer-implemented method, comprising:

on a local network node, establishing a first session with a remote network node on a transport stream in accordance with a connectionless transport protocol;

on behalf of one or more software entities on the local network node, automatically opening one or more channels over which data is transmitted between the local network node and the remote network node in the first session;

in the first session, maintaining a table identifying open ones of the channels and associating respective attribute values with the identified channels;

in response to a determination that the first session has failed, automatically attempting to establish a second session with the remote network node on a second transport stream in accordance with the connectionless transport protocol; and

in response to successful establishment of the second session, automatically opening each of the channels identified in the table.

89. The method of claim 88, wherein the establishing comprises determining a first station definition assigned to the remote network node and the maintaining comprises storing the first station definition in the table as an attribute of each of the open channels.

90. The method of claim 89, further comprising discovering a failure of the first session, wherein the discovering comprises determining a current station definition assigned to the remote network node and determining that the first session has failed in response to a determination that the current station definition is different from the first station definition.

91. The method of claim 89, wherein the determining comprises parsing a station definition record received from the remote network node, wherein the station definition record comprises a set of fields, each of the fields is defined by a respective field type and an associated field value, and each of the field types is identified by a respective globally unique identifier (GUID).

92. The method of claim 88, further comprising recording attributes of local publish channels available from the local network node, local subscribe channels requested by the one or more software entities, remote publish channels available from the remote network node, and remote subscribe channels requested by the remote network node.

93. The method of claim 92, wherein the recording comprises maintaining for each of the local publish channels a record comprising an identifier of one of the software entities indicating a capacity to publish data on the local publish channel, an identifier of a remote network node subscribing to the local publish channel, and an identifier of the local publish channel.

94. The method of claim 92, wherein the recording comprises maintaining for each of the local subscribe channels a record comprising an identifier of one of the software entities subscribing to the local subscribe channel, an identifier of a remote network node indicating a capacity to publish data on the local subscribe channel, an identifier of the local subscribe channel, and one or more network transport parameters associated with the local subscribe channel.

95. The method of claim 92, wherein the recording comprises maintaining for each of the remote publish channels a record comprising an identifier of a remote network node indicating a capacity to publish data on the remote publish channel, and an identifier of the remote publish channel.

96. The method of claim 92, wherein the opening comprises sending to the remote network node records defining the local publish channels.

97. The method of claim 92, wherein the opening comprises sending to the remote network node a record of each of the local subscribe channels having an identifier that matches an identifier of one of the remote publish channels.

98. The method of claim 88, wherein the establishing comprises:

creating a definition of the session comprising an internet protocol (IP) address, a port address, and a globally unique identifier of a transport protocol; and

sending the definition to the remote network node.

99. The method of claim 88, further comprising transmitting data between the local network node and the remote network node on the one or more open channels in the session.

100. The method of claim 99, wherein the transmitting comprises transmitting the data in records, each of the records comprises a set of fields, each of the fields is defined by a respective field type and an associated field value, and each of the field types is identified by a respective GUID.

101. The method of claim 99, wherein the transmitting comprises transmitting media records containing media data comprising packets of renderable data, and transmitting configuration records containing configuration data comprising definitions of configuration settings.

102. The method of claim 101, wherein the transmitting comprises encapsulating media records and configuration records in transport records over the transport stream.

103. The method of claim 102, wherein the encapsulating comprises compressing ones of the media records using a first data compression service and compressing ones of the configuration records using a second data compression service.

104. The method of claim 102, wherein the encapsulating comprises associating the transport records with identifiers of respective ones of the channels on which they are transmitted, encrypting the transport records, and sequencing the encrypted transport records.

105. The method of claim 102, further comprising at the local network node receiving ones of the transport records transmitted from the remote network node, wherein the receiving comprises decrypting the transport records and dispatching the media records and the configuration records contained in the decrypted transport records to subscribing ones of the software entities.

106. Apparatus, comprising:

a computer-readable medium storing computer-readable instructions; and

a data processing unit coupled to the memory, operable to execute the instructions, and based at least in part on the execution of the instructions operable to perform operations comprising

on a local network node, establishing a first session with a remote network node on a transport stream in accordance with a connectionless transport protocol;

on behalf of one or more software entities on the local network node, automatically opening one or more channels over which data is transmitted between the local network node and the remote network node in the first session;

in the first session, maintaining a table identifying open ones of the channels and associating respective attribute values with the identified channels;

in response to a determination that the first session has failed, automatically attempting to establish a second session with the remote network node on a second transport stream in accordance with the connectionless transport protocol; and

in response to successful establishment of the second session, automatically opening each of the channels identified in the table.

107. At least one computer-readable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed by a computer to implement a method comprising:

on a local network node, establishing a first session with a remote network node on a transport stream in accordance with a connectionless transport protocol;

on behalf of one or more software entities on the local network node, automatically opening one or more channels over which data is transmitted between the local network node and the remote network node in the first session;

in the first session, maintaining a table identifying open ones of the channels and associating respective attribute values with the identified channels;

in response to a determination that the first session has failed, automatically attempting to establish a second session with the remote network node on a second transport stream in accordance with the connectionless transport protocol; and

in response to successful establishment of the second session, automatically opening each of the channels identified in the table.

108. A method performed on a local network node, the method comprising:

parsing a list of kernel components comprising one or more kernel service components;

determining all the kernel components in the parsed list that are missing from a local repository;

retrieving each of the kernel components determined to be missing;

instantiating kernel services from ones of the kernel service kernel components;

executing the instantiated kernel services to communicate with one or more remote network nodes in a communication environment defined with respect to a virtual area.

109. The method of claim 108, wherein the instantiating comprises instantiating a stream connection kernel service, and the executing comprises executing the stream connection kernel service to dynamically load at least one stream transport plugin providing at least one of a reliability function, an authentication function, and an encryption function.

110. The method of claim 109, wherein the executing comprises dynamically loading the at least one stream transport plugin in response to a network connection definition received from one of the remote network nodes.

111. The method of claim 108, wherein the instantiating comprises instantiating a realtime scheduler kernel service, and the executing comprises executing the realtime scheduler kernel service to dynamically load a time service plugin providing a time synchronization function.

112. The method of claim 111, wherein the executing comprises dynamically loading the time service plugin in response to a network connection definition received from one of the remote network nodes.

113. The method of claim 108, wherein the instantiating comprises instantiating one or more stream handling kernel services, and the executing comprises executing the one or more stream handling kernel services to dynamically create and configure at least one stream handler from one or more plugins providing stream processing functions.

114. The method of claim 113, wherein the executing comprises dynamically creating and configuring the stream handler in response to a stream handler specification received from one of the remote network nodes.

115. The method of claim 114, wherein the executing comprises assembling multiple ones of the plugins into a directed graph in accordance with the stream handler specification.

116. The method of claim 115, wherein the executing comprises assembling one of the plugins into a second directed graph in accordance with a second stream handler specification received from the one remote network node, the first and second directed graphs having different respective plugin topologies.

117. The method of claim 114, wherein the configuring comprises dynamically configuring the stream handler while the stream handler is processing a realtime data stream received from one of the remote network nodes.

118. The method of claim 114, wherein the one or more remote network nodes are associated with respective objects in the virtual area, and the configuring comprises determining configuration parameter values based on positions of objects in the virtual area and configuring ones of the plugins in the stream handler with the configuration parameter values.

119. The method of claim 108, further comprising on the local network node

declaring to a network infrastructure service an intention to enter the virtual area, and

receiving from the network infrastructure service an identification of plugins that are needed to render the virtual area.

120. The method of claim 119, further comprising on the local network node

retrieving from a remote network node ones of the plugins that are missing from the local network node.

121. The method of claim 119, further comprising loading at least one of the plugins and invoking one or more functions of the loaded plugin in a process of rendering the virtual area on the local network node.

122. The method of claim 108, further comprising establishing a network session between the local network node and one of the remote network nodes, wherein the establishing comprises receiving an identification of a set of variants of an identified transport application programming interface (API), selecting one of the variants from the set, and invoking one or more functions of the selected variant in a process of transferring a realtime data stream between the local network node and the one remote network node on the session.

123. The method of claim 122, wherein the invoking comprises loading a transport plugin supporting the identified transport API and invoking one or more functions of the transport plugin.

124. Apparatus, comprising:

a computer-readable medium storing computer-readable instructions; and

a data processing unit coupled to the memory, operable to execute the instructions, and based at least in part on the execution of the instructions operable to perform operations comprising

parsing a list of kernel components comprising one or more kernel service components,

determining all the kernel components in the parsed list that are missing from a local repository,

retrieving each of the kernel components determined to be missing,

instantiating kernel services from ones of the kernel service kernel components, and

executing the instantiated kernel services to communicate with one or more remote network nodes in a communication environment defined with respect to a virtual area.

125. At least one computer-readable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed by a computer to implement a method comprising:

parsing a list of kernel components comprising one or more kernel service components;

determining all the kernel components in the parsed list that are missing from a local repository;

retrieving each of the kernel components determined to be missing;

instantiating kernel services from ones of the kernel service kernel components; and

executing the instantiated kernel services to communicate with one or more remote network nodes in a communication environment defined with respect to a virtual area.

126. A method performed on a local network node, comprising:

configuring the local network node to support realtime communications with at least one remote network node in a context defined by a virtual area, wherein the configuring comprises

in response to a call to enumerate all plugins that support a specified application programming interface (API), returning a list comprising identifiers of all plugins associated with the specified API in a plugin database,

in response to a call to enumerate variants of a given API supported by an identified one of the plugins, delivering a list comprising identifiers of all variants of the given API that are supported by the identified plugin, and

in response to a call to instantiate an identified one of the variants of an identified API supported by an identified one of the plugins, loading the identified plugin and providing a pointer to an instance of the identified variant; and

establishing at least one realtime data stream connection between the configured local network node and the at least one remote network node.

127. The method of claim 126, wherein

the loading comprises creating a base plugin object and the returned pointer points to the base plugin object, and

further comprising executing the identified variant instance, wherein the executing comprises casting the base plugin object to the identified variant through inheritance.

128. The method of claim 126, wherein the communicating comprises instantiating ones of the plugins in a set in response to calls comprising identifiers of the plugins in the set and identifiers of one or more of the APIs respectively supported by the plugins in the set, and assembling the instantiated plugins into a directed graph.

129. The method of claim 128, wherein the assembling is performed in accordance with a stream handling specification received from a remote network node.

130. The method of claim 126, wherein the returning, the delivering, and the loading, are performed independently of API type.

131. The method of claim 126, wherein at least one of the plugins supports multiple ones of the APIs and multiple variants of at least one of the multiple APIs that it supports.

132. The method of claim 126, further comprising, communicating with one or more remote network nodes in a communication environment defined with respect to a virtual area, wherein the communicating comprises executing the identified variant instance.

133. The method of claim 132, wherein the communicating comprises instantiating at least one of the plugins that provides a stream transport function.

134. The method of claim 132, wherein the communicating comprises instantiating at least one of the plugins that provides an audio stream processing function.

135. The method of claim 132, wherein the communicating comprises instantiating at least one of the plugins that provides a visual graphical effect function.

136. The method of claim 132, wherein the communicating comprises instantiating at least one of the plugins that provides a collision detection function.

137. The method of claim 126, further comprising:

discovering plugins available on the local network node;

querying the plugins for all application programming interfaces (APIs) that they support; and

based on the querying, storing associations between the plugins and the APIs that they respectively support in a plugin database on a computer-readable medium.

138. Apparatus, comprising:

a computer-readable medium storing computer-readable instructions; and

a data processing unit coupled to the memory, operable to execute the instructions, and based at least in part on the execution of the instructions operable to perform operations comprising

configuring the local network node to support realtime communications with at least one remote network node in a context defined by a virtual area, wherein the configuring comprises

in response to a call to enumerate all plugins that support a specified application programming interface (API), returning a list comprising identifiers of all plugins associated with the specified API in a plugin database,

in response to a call to enumerate variants of a given API supported by an identified one of the plugins, delivering a list comprising identifiers of all variants of the given API that are supported by the identified plugin, and

in response to a call to instantiate an identified one of the variants of an identified API supported by an identified one of the plugins, loading the identified plugin and providing a pointer to an instance of the identified variant; and

establishing at least one realtime data stream connection between the configured local network node and the at least one remote network node.

139. At least one computer-readable medium having computer-readable program code embodied therein, the computer-readable program code adapted to be executed by a computer to implement a method comprising:

configuring the local network node to support realtime communications with at least one remote network node in a context defined by a virtual area, wherein the configuring comprises

in response to a call to enumerate all plugins that support a specified application programming interface (API), returning a list comprising identifiers of all plugins associated with the specified API in a plugin database,

in response to a call to enumerate variants of a given API supported by an identified one of the plugins, delivering a list comprising identifiers of all variants of the given API that are supported by the identified plugin, and

in response to a call to instantiate an identified one of the variants of an identified API supported by an identified one of the plugins, loading the identified plugin and providing a pointer to an instance of the identified variant; and

establishing at least one realtime data stream connection between the configured local network node and the at least one remote network node.