Distributing membership information for multi-party application layer sessions

• US 8,103,753 B2
• Filed: 04/22/2003
• Issued: 01/24/2012
• Est. Priority Date: 04/22/2003
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Taylor, John Anthony, Zhong, Wei
• Primary Examiner(s): Bates, Kevin
• Assistant Examiner(s): AILES, BENJAMIN A
• Application Number:
  US10/420,986
• Publication Number:
  US 20040215667A1
• Time in Patent Office: 3,199 Days
• Field of Search: 709/204, 709/223, 370/254
• US Class Current: 709/222
• 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. A method, performed by a joining side application layer process at a joining computer system having a memory and a processor, for joining a multi-party application layer session including at least an inviting computer system being network connectable to the joining computer system, the method comprising:

with a processor, sending a hello message to the inviting computer system;

prior to the joining computer system being joined to the multi-party application layer session, 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;

in response to receiving the inviting side link database, with a processor, updating a joining side link database at the joining computer based on the received inviting side link database to at least indicate that the joining computer system is logically linked to the inviting computer system; and

sending the updated joining side link database to a third computer system, the updated joining side link database including a joining side link state record indicating that the joining computer system is logically linked to the inviting computer system, wherein the third computer system is configured to update a third link database at the third computer system based on the updated joining side link database to at least indicate that the joining computer system is logically linked to the inviting computer system, wherein the joining side link state record is a schema-based XML link state record.

2. The method of claim 1, further comprising:

receiving, at a joining side lower protocol layer situated below the joining side application layer process in a protocol stack, 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.

3. The method of claim 1, wherein sending the hello message comprises sending a sync message including one or more link state records.

4. The method of claim 3, wherein sending the hello message comprises sending the hello message within a specified threshold of time calculated based on a reply interval sent to the joining computer system.

5. The method of claim 1, wherein receiving the inviting side link database comprises 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 of claim 1, wherein receiving the inviting side link database comprises receiving a schema-based inviting side link database.

7. A first computing system having a memory and a processor for communicating with other computing systems in a multi-party session, the first computing system comprising:

a first link database configured to store a list of neighbors of computing systems in the multi-party session, a neighbor of one computing system being a computing system that is linked to the one computing system;

a component configured to join the first computing system to the multi-party session at least in part by sending a first hello message to a second computing system participating in the multi-party session;

a component configured to receive a second hello message from a third computing system and, in response to receiving the second hello message from the third computing system, send an indication of the first link database to the third computing system; and

a component configured to,

receive an indication of a second link database from a first neighbor computing system, the second link database storing a list of neighbors of the first neighbor computing system, wherein the second link database is a schema-based link database,

receive at least one XML instruction defined in accordance with the schema, and

in response to receiving the indication of the second link database from the first neighbor computing system,

upon determining that the first link database is to be updated based on data of the second link database,

update the first link database based on data of the second link database, and

send an indication of the updated first link database to at least one neighbor computing system of the first computing system;

so that when a computing system joins the multi-party session, updated link databases are propagated to computing systems participating in the multi-party session.

8. The first computing system of claim 7, wherein the component configured to send the first hello message is further configured to send a sync message including one or more link state records.

9. The first computing system of claim 7, wherein the component configured to receive an indication of a second link database is further configured to receive one or more link state records, each link state record indicating one or more logical links between computing systems participating in the multi-party application layer session.

10. The first computing system of claim 7, wherein the component configured to update the first link database is further configured to add the second computing system to a neighbor list for the first computing system.

11. The first computing system of claim 7, wherein the component configured to update the first link database is further configured to replace a current version of a link state record in the first link database with an updated version of the link state record received from the second computing system.

12. A method performed by a first computer having a memory and a processor for communicating with other computers in a multi-party session, the method comprising:

storing, in a first link database, a list of neighbors of computers in the multi-party session, a neighbor of one computer being a computer that is linked to the one computer;

sending a first hello message to a second computer participating in the multi-party session;

prior to the first computer system being joined to the multi-party session, receiving an indication of a second link database from the second computer, the first link database and the second link database storing a list of neighbors of the second neighbor computer; and

in response to receiving the indication of the second link database,

upon determining that the first link database is to be updated based on data of the second link database,

with a processor, updating the first link database based on data of the second link database, and

sending an indication of the updated first link database to at least one neighbor computer of the first computer, wherein sending the indication of the updated first link database comprises sending a schema-based link state record and wherein sending the schema-based link state record comprises sending an XML link state record.

13. The method of claim 12, further comprising:

receiving a second hello message from a third computer.

14. The method of claim 13, further comprising:

in response to receiving the second hello message, sending an indication of the first link database to the third computer.

15. The method of claim 13, wherein receiving the second hello message comprises receiving the second hello message within a specified threshold of time calculated based on a reply interval sent to the third computer.

16. The method of claim 12, wherein the first computer and the second computer are both participant computers in the multi-party session prior to the first computer sending the first hello message.