Distributing membership information for multi-party application layer sessions

• US 20040215667A1
• Filed: 04/22/2003
• Published: 10/28/2004
• Est. Priority Date: 04/22/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Taylor, John Anthony, Zhong, Wei
• Granted Patent: US 8,103,753 B2
• Time in Patent Office: Days
• US Class Current: 707/201
• CPC Class Codes: H04L 12/1818 Conference organisation arrangements, e.g. handling schedules, setting up parameters needed by nodes to attend a conference, booking network resources, notifying involved parties
• CPC Class Codes: H04L 12/1822 Conducting the conference, e.g. admission, detection, selection or grouping of participants, correlating users to one or more conference sessions, prioritising transmission
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

Membership information for participating computer systems participating in a multi-party conferencing session is distributed by intermittently exchanging link databases with one or more neighbor computer systems. A link database includes one or more link state records, each link state record identifying a participating computer systems and a list of neighbor computer systems that are logically linked to the participating computer system. When a new computer system joins or a participating computer system leaves the multi-party session this joining or leaving change is reflected in the link databases of corresponding neighbor computer systems. As the neighbor computer systems exchange link databases, the change is eventually propagated to all the participating computer systems. Accordingly, participant computer systems continually transition towards a steady state where each participant computer system is aware of other participant computer systems and logical links associated with other participant computer systems.

Claims

1. In a multi-party application layer session including at least an inviting computer system, the inviting computer system being network connectable to a joining computer system such that the joining computer system and inviting computer system can communicate by transferring electronic messages, a method for a joining side application layer process at the joining computer system to join the multi-party application layer session, the method comprising:

an act of sending a hello message to the inviting computer system;

an act of receiving an inviting side link database from the inviting computer system, the inviting side link database including an inviting side link state record indicating that the inviting computer system is logically linked to the joining computer system;

an act of updating a joining side link database to at least indicate that the joining computer system is logically linked to the inviting computer system in response to receiving the inviting side link database; and

an act of sending an updated joining side link state record to the inviting computer system, the updated joining side link state record indicating that the joining computer system is logically linked to the inviting computer system.

2. The method as recited in claim 1, further comprising:

an act of a joining side lower protocol layer, situated below the joining side application layer process in a protocol stack, receiving security information from a corresponding inviting side lower protocol layer prior to sending the hello message, the security information for authenticating with the multi-party application layer session.

3. The method as recited in claim 1, fairther comprising:

an act of a joining side lower protocol layer, situated below the joining side application layer process in a protocol stack, receiving an entry point from a corresponding inviting side lower protocol layer prior to sending the hello message, the entry point for connecting to the inviting side computer system to exchange lower layer connection data.

4. The method as recited in claim 1, wherein the act of sending a hello message comprises an act of sending a sync message including one or more link state records.

5. The method as recited in claim 1, wherein the act of receiving an inviting side link database comprises an act of receiving one or more link state records, each link state record indicating one or more logical links between computer systems participating in the multi-party application layer session.

6. The method as recited in claim 1, wherein the act of receiving an inviting side link database comprises an act of receiving a schema-based inviting side link database.

7. The method as recited in claim 6, wherein the act of receiving a schema-based inviting side link database comprises an act of receiving XML instruction defined in accordance with an XML schema.

8. The method as recited in claim 1, wherein the act of updating a joining side link database includes an act of adding the inviting computer system to a neighbor list for the joining computer system.

9. The method as recited in claim 1, wherein the an act of updating a joining side link database comprises an act of replacing a current version of a link state record in the joining link database with an updated version of the link state record received from the inviting computer system.

10. The method as recited in claim 1, wherein the an act of updating a joining side link database comprises an act of indicating that the joining side application layer process is logically connected to a corresponding inviting side application layer process such that the joining side application layer process and the inviting side application layer process can exchange conferencing data.

11. The method as recited in claim 1, wherein the act of sending an updated joining side link state record to the inviting computer system comprises an act of sending a schema-based link state record.

12. The method as recited in claim 11, wherein the act of sending a schema-based link state record comprises an act of sending an XML link state record defined in accordance with an XML schema.

13. The method as recited in claim 1, further comprising:

an act of receiving a second updated inviting side link database including a link state record that indicates the inviting computer system is a neighbor of the joining computer system.

14. The method as recited in claim 1, wherein the joining computer system and the inviting computer system are both participant computer systems in the multi-party application layer session prior to the joining side computer system sending the hello message.

15. The method as recited in claim 1, wherein the multi-party application layer session is multi-party conferencing session.

16. In a multi-party application layer session including at least an inviting computer system, the inviting computer system being network connectable to a joining computer system such that the joining computer system and inviting computer system can communicate by transferring electronic messages, a method for an inviting side application layer process at the inviting computer system to invite the joining computer system to join the multi-party application layer session, the method comprising:

an act of receiving a hello message from the joining computer system;

an act of updating an inviting side link database to indicate the inviting computer system is logically linked to the joining computer system in response to receiving the hello message;

an act of sending the updated inviting side link database to the joining computer system, the updated inviting side link database including at least an inviting side link state record indicating that the inviting computer system is logically linked to the joining computer system; and

an act of receiving a joining side link state record from the joining computer system, the joining side link state record indicating that the joining computer system is logically linked to the inviting computer system.

17. The method as recited in claim 16, further comprising:

an act of an inviting side lower protocol layer, situated below the inviting side application layer process in a protocol stack, sending security information to a corresponding joining side lower protocol layer prior to receiving the hello message, the security information for authenticating with the multi-party application layer session.

18. The method as recited in claim 16, further comprising:

an act of an inviting side lower protocol layer, situated below the inviting side application layer process in a protocol stack, advertising an entry point to a corresponding joining side lower protocol layer prior to receiving the hello message, the security entry point for connecting to the joining side computer system to exchange lower layer connection data.

19. The method as recited in claim 16, wherein the act of receiving a hello message from the joining computer system comprises an act of receiving the hello message within a specified threshold, the specified threshold being calculated from a reply interval previously sent to the joining computer system.

20. The method as recited in claim 16, wherein the act of receiving a hello message from the joining computer system comprises an act of sync message that includes one or more link state records.

21. The method as recited in claim 16, wherein the act of updating an inviting side link database comprises an act of adding the joining computer system to a neighbor list that corresponds to the inviting computer system.

22. The method as recited in claim 16, wherein the an act of updating an inviting side link database comprises an act of indicating that the inviting side application layer process is logically connected to a corresponding joining side application layer process such that the inviting side application layer process and the joining side application layer process can exchange conferencing data.

23. The method as recited in claim 16, wherein the act of sending the updated inviting side link database to the joining computer system comprises an act of sending one or more link state records, each link state record indicating one or more logical links between computer systems in the multi-party application layer session.

24. The method as recited in claim 16, wherein the act of sending the updated inviting side link database to the joining computer system comprises an act of sending a schema-based inviting side link database.

25. The method as recited in claim 16, wherein the act of sending a schema-based inviting side link database comprises an act of sending XML instructions defined in accordance with an XML schema.

26. The method as recited in claim 16, wherein the act of receiving a joining side link state record comprises an act of receiving a schema-based link state record.

27. The method as recited in claim 26, wherein the act of receiving a schema-based link state record comprises an act of receiving an XML link state record defined in accordance with an XML schema.

28. The method as recited in claim 16, further comprising:

an act of further updating the inviting side link database to include the joining side link state record.

29. The method as recited in claim 28, further comprising:

an act of sending the further updated inviting side link database to at least one computer system included in a neighbor list for the inviting computer system such that the joining side link state record is propagated to other computer systems participating in the multi-party application layer session.

30. The method as recited in claim 16, wherein the inviting computer system and the receiving computer system are both participant computer systems in the multi-party application layer session prior to the inviting side computer system receiving the hello message.

31. The method as recited in claim 16, wherein the multi-party application layer session is a multi-party conferencing session.

32. In a multi-party application layer session having a plurality of network connectable participant computer systems including a repairing computer system and a neighbor computer system, the neighbor computer system being in a neighbor list for the repairing computer system, a method for an application layer process at the repairing computer system to initiate a repair of the multi-party application layer session, the method comprising:

an act of detecting that link data is no longer being received from the neighbor computer system;

an act of removing the neighbor computer system from the repairing computer system'"'"'s neighbor list;

an act of removing the neighbor computer system'"'"'s link state record from a repair side link database;

an act of identifying a list of logically unreachable participant computer systems based on remaining link state records in the repair side link database; and

an act of attempting to join at least one logically unreachable participant computer so as to repair the multi-party session.

33. The method as recited in claim 32, wherein the an act of detecting that link data is no longer being received from the neighbor computer system comprises an act of a reply timer expiring.

34. The method as recited in claim 32, wherein the an act of detecting that link data is no longer being received from the neighbor computer system comprises an act of not receiving a heartbeat message within a specified response interval.

35. The method recited in claim 32., wherein the act of identifying a list of logically unreachable participant computer systems based on link state records in the repair side link database comprises an act of identifying a participant computer system that is not reachable through any combination of links included in the repairing side link database.

36. The method as recited in claim 32, wherein the act of attempting to join at least one logically unreachable participant computer so as to repair the multi-party session comprises an act of sending a hello message to the a logically unreachable participant computer system.

37. The method as recited in claim 32, wherein the act of attempting to join at least one logically unreachable participant computer so as to repair the multi-party session comprises an act of attempting to join each logically unreachable participant computer system identified in the list of logically unreachable participant computer systems.

38. A computer program product for use in a multi-party application layer session including at least an inviting computer system, the inviting computer system being network connectable to a joining computer system such that the joining computer system and inviting computer system can communicate by transferring electronic messages, the computer program product for implementing a method for a joining side application layer process at the joining computer system to join the multi-party application layer session, the computer program product comprising one or more computer-readable media having stored thereon computer executable instructions that, when executed by a processor, cause the joining computer system to perform the following:

send a hello message to the inviting computer system;

receive an inviting side link database from the inviting computer system, the inviting side link database including an inviting side link state record indicating that the inviting computer system is logically linked to the joining computer system;

update a joining side link database to at least indicate that the joining computer system is logically linked to the inviting computer system in response to receiving the inviting side link database; and

send an updated joining side link state record to the inviting computer system, the updated joining side link state record indicating that the joining computer system is logically linked to the inviting computer system.

39. The computer program product as recited in claim 38, wherein the one or more computer-readable media are physical media.

40. A computer program product for use in a multi-party application layer session including at least an inviting computer system, the inviting computer system being network connectable to a joining computer system such that the joining computer system and inviting computer system can communicate by transferring electronic messages, the computer program product for implementing a method for an inviting side application layer process at the inviting computer system to invite the joining computer system to join the multi-party application layer session, the computer program product comprising one or more computer-readable media having stored thereon computer executable instructions that, when executed by a processor, cause the joining computer system to perform the following:

receive a hello message from the joining computer system;

update an inviting side link database to indicate the inviting computer system is logically linked to the joining computer system in response to receiving the hello message;

send the updated inviting side link database to the joining computer system, the updated inviting side link database including at least an inviting side link state record indicating that the inviting computer system is logically linked to the joining computer system; and

receive a joining side link state record from the joining computer system, the joining side link state record indicating that the joining computer system is logically linked to the inviting computer system.

41. The computer program product as recited in claim 40, wherein the one or more computer-readable media are physical media.

42. A computer program product for use in a multi-party application layer session having a plurality of network connectable participant computer systems including a repairing computer system and a neighbor computer system, the neighbor computer system being in a neighbor list for the repairing computer system, the computer program product for implementing a method for an application layer process at the repairing computer system to initiate a repair of the multi-party application layer session, the computer program product comprising one or more computer-readable media having stored thereon computer executable instructions that, when executed by a processor, cause the joining computer system to perform the following:

detect that link data is no longer being received from the neighbor computer system;

remove the neighbor computer system from the repairing computer system'"'"'s neighbor list;

remove the neighbor computer system'"'"'s link state record from a repair side link database;

identify a list of logically unreachable participant computer systems based on w the remaining link state records contained in the repair side link database; and

attempt to join at least one logically unreachable participant computer so as to repair the multi-party session.

43. The computer program product as recited in claim 42, wherein the one or more computer-readable media are physical media.

44. One or more computer-readable media having stored thereon a data structure for representing a link state record, the data structure comprising the following:

a computer system identifier field representing a computer system identifier for identifying a participating computer system participating in a multi-party application layer session; and

a neighbor list field representing a list of one or more neighbor computer systems that are logically linked to the participating computer system identified in the computer system identifier field.

45. The one or more computer-readable media having stored thereon a data structure representing a link state record in accordance with claim 44, wherein the neighbor list field is comprised of:

one or more neighbor computer system identifier fields, each neighbor computer system identifier field representing a neighbor computer system identifier for identifying a neighbor computer system that is logically linked to the participating computer system represented in the computer system identifier field.

46. The one or more computer-readable media having stored thereon a data structure representing a link state record in accordance with claim 44, the data structure further comprising:

a computer system metadata field representing metadata used to describe the participating computer system represented in the computer system identifier field.

47. The one or more computer-readable media having stored thereon a data structure representing a link state record in accordance with claim 44, the data structure further comprising:

a timestamp field representing a time the participating computer system represented in the computer system identifier field generated the data structure representing the link state record.

48. One or more computer-readable media having stored thereon a data structure for representing a link database, the data structure comprising the following:

a computer system identifier field representing a computer system identifier for identifying a participating computer system that that sent the link state database, the participating computer system participating in a multi-party application layer session;

a reply interval field representing a reply interval value, the reply interval value being used as the basis for a reply threshold that indicates how long the participating computer system represented in the computer system identifier field will wait for a response to sending the link database before detecting that link data is no longer being received from a neighbor computer system; and

a link state record field representing one or more link state records for other participating computer systems participating in the multi-party application layer session along with the computer system represented in the computer system identifier field.

49. One or more computer-readable media having stored thereon a data structure representing a schema that defines a format for transferring link data from a link database, the data structure comprising:

a from field defining a format for identifying a computer system that is to transfer link data from a link database;

an interval field defining a format for representing a reply interval that is used as a basis for a reply threshold, the reply threshold indicating how long a computer system, identified in accordance with the identification format defined in the from field, is to wait for a response to sending link data before detecting that link data is no longer being received from a neighbor computer system; and

a node type field defining a format for representing one or more computer systems having link data that will be transferred by a computer system identified in accordance with the identification format defined in the from field.

50. The one or more computer-readable media having thereon a data structure representing a schema that defines a format for transferring link data from a link database as recited in claim 49, wherein the node type field is comprised of:

a node uri field defining a node format for identifying a computer system having link data that will be transferred by a computer system identified in accordance with the identification format defined in the from field;

a name field defining a format for representing metadata associated with a computer system identified in accordance with the node identification format defined in the node uri field; and

a link type field defining a format for representing one or more computer systems that are logically linked to a computer system identified in accordance with the node uri field format in the node uri field.

51. The one or more computer-readable media having thereon a data structure representing a schema that defines a format for transferring link data from a link database as recited in claim 49, wherein the link type field is comprised of:

a link uri field defining a format for identifying a computer system that is logically linked to a computer system identified in accordance with the node uri field format in the node uri field.