Signaling method for internet telephony

1. A method for communicating via a conference bridge, the method comprising:

receiving, at at least a first party, an invitation message from a second party, the invitation message including an identifier of the conference bridge, the invitation message being a session initiation protocol (SIP) message;

sending, from at least the first party to the conference bridge, a request to establish communication with the conference bridge, the request including the identifier identifying the conference bridge; and

establishing communication between the first party and the conference bridge in response to the request; wherein

the identifier is a URI.

2. The method of claim 1 , wherein the establishing step further establishes a multi-party conference.

3. The method of claim 2 , wherein the at least a first party includes a plurality of first parties, each of the plurality of first parties sending a request to the conference bridge, and each of the requests including the URI identifying the conference bridge.

4. The method of claim 2 , wherein the establishing step further comprises:

receiving, from the conference bridge, an acceptance message in response to the request.

5. The method of claim 1 , wherein the established communication joins the first party to an existing multi-party conference between at least two participating parties via the conference bridge.

6. The method of claim 5 , wherein the request is an INVITE message.

7. The method of claim 5 , wherein the request identifies a first of the at least two participating parties in the existing multi-party conference.

8. The method of claim 7 , wherein the first participating party is identified in a header of the request.

9. The method of claim 5 , further comprising:

sending, from a first of the at least two participating parties to the first party, an INVITE message identifying the URI of the conference bridge; and wherein

the first party sends the request to the conference bridge in response to the INVITE message.

10. The method of claim 5 , further comprising:

receiving, at the first party from the conference bridge over which the existing multi-party conference is being held, a first instruction message instructing the first party to request to join the existing multi-party conference; and wherein

the first party sends the request in response to the received instruction message.

11. The method of claim 10 , wherein the request message identifies a first of the at least two participating parties.

12. The method of claim 5 , further comprising:

receiving, at the first party, a first instruction message from a first of the at least two participating parties in the existing multi-party conference, the first instruction message instructing the first party to request to join the existing multi-party conference; and wherein

the first party sends the request in response to the received instruction message.

13. The method of claim 12 , wherein the request identifies the first participating party.

14. A method for joining an existing multi-party conference call between at least two participating parties using a conference bridge, the method comprising:

sending, from the conference bridge to a first party, a first request message to join the existing multi-party conference, the first request message including an identifier identifying the first party, and the first request message being a session initiation protocol (SIP) message; wherein

the identifier is a URI.

15. The method of claim 14 , wherein the first request message is an INVITE message.

16. The method of claim 14 , further comprising:

joining the existing multi-party conference in response to the first request message.

17. The method of claim 14 , further comprising:

requesting, by a first of the at least two participating parties, that the conference bridge send the first request message; wherein

the identity of the first participating party is identified in a header of the request.

18. The method of claim 14 , further comprising:

establishing, between the first party and a first of the at least two participating parties, a communication connection outside of the existing multi-party conference prior to the sending step; and

terminating, after establishing communication between the first party and the conference bridge, the communication connection between the first party and the first participating party such that the first party and the first participating party communicate as part of the existing multi-party conference; wherein

the conference bridge sends the first request message in response to instructions received from the first participating party.

19. The method according to claim 18 , further comprising:

having the first participating party send a second request message to the conference bridge instructing the conference bridge to establish the communication connection with the first party, the second request message including a header field specifying the first participating party and causing the bridge to send the first request message to the first party.

20. The method according to claim 19 , wherein the second request message is an INVITE request message, and the header field included in the second request message specifies the first party.

21. The method according to claim 19 , wherein the second request message also instructs the first party to terminate the communication connection between the first party and the first participating party.

22. The method according to claim 21 , wherein the first request message is an INVITE request message including a REPLACES header field specifying the first participating party.

23. The method of claim 14 , further comprising:

receiving, at the conference bridge, a second request message from the first party, the second request message requesting that the first party join the existing multi-party conference; and

establishing a communication connection with the first party for joining the first party to the existing multi-party conference in response to the second request message.

24. The method of claim 23 , wherein the second request message identifies a first of the at least two participating parties.

25. In a computer network, a method for adding a first party to an existing bridged conference between at least two second parties, the method comprising:

sending, from a second party to a bridge over which the bridged conference is being held, a first instruction message instructing the bridge to add the first party to the existing bridged conference and instructing the bridge to send a first request message to the first party, the first request message requesting that the first party establish a communication connection with the bridge for joining the first party to the existing bridged conference, the first instruction message and the first request message being session initiation protocol (SIP) messages; wherein

the first instruction message includes a first identifier identifying the bridge, and

the first identifier is a URI.

26. The method of claim 25 , wherein the first instruction message further includes a second identifier identifying the first party.

27. In a computer network, a method for adding a first party to an existing bridged conference between at least two second parties, the method comprising:

receiving, at a bridge over which the bridged conference is being held, a first instruction message from a second party, the first instruction message instructing the bridge to add the first party to the existing bridged conference and instructing the bridge to send a first request message to the first party, the first request message requesting that the first party establish a communication connection with the bridge for joining the first party to the existing bridged conference, the first instruction message and the first request message being session initiation protocol (SIP) messages; wherein

the first instruction message includes a first identifier identifying the bridge, and

the first identifier is a URI.

28. The method of claim 27 , wherein the first instruction message further includes a second identifier identifying the first party.

29. In a computer network, a method for adding a first party to an existing bridged conference between at least two second parties over a conference bridge, the method comprising:

sending, from a second party to the first party, a first request message requesting that the first party establish a communication connection with the bridge for joining the existing bridged conference, the first request message including a first identifier identifying the bridge and a second identifier identifying the second party having sent the first request message, the first request message being a session initiation protocol (SIP) message; and

communicating with the first party as part of the existing bridged conference; wherein

the first identifier is a URI.

30. In a computer network, a method for adding a first party to an existing bridged conference between at least two second parties over a conference bridge, the method comprising:

receiving, at the first party, a first request message from a second party, the first request message requesting that the first party establish a communication connection with the bridge for joining the existing bridged conference, the first request message including a first identifier identifying the bridge and a second identifier identifying the second party having sent the first request message, the first request message being a session initiation protocol (SIP) message; and

communicating with the second party as part of the existing bridged conference; wherein

the first identifier is a URI.

31. A method by which a first party participating in a network conference with a plurality of second parties invites a conference bridge into the conference so as to establish a bridged conference, comprising the steps of:

having the first party establish a communication connection with the conference bridge;

having the first party identify each second party to the conference bridge;

having the conference bridge instruct each second party to communicate with the conference bridge in place of the remaining second parties; wherein

said step of having the conference bridge instruct each second party to communicate with the conference bridge in place of the remaining second parties includes,

having the conference bridge send a first INVITE request message to each second party so as to establish a communication connection with each second party, each first INVITE request message including a REPLACES header field acting to instruct each second party to replace the communication connection between the second party and the first party with the communication connection established between the second party and the conference bridge,

having the second party respond to the first INVITE request message sent by the conference bridge so as to indicate acceptance or rejection of the establishment of a communication connection between the second party and the conference bridge, and

for each accepting second party, having the conference bridge send a second INVITE request message to each remaining second party besides the accepting second party, the second INVITE request message containing a REPLACES header field containing the accepting second party and acting to cause each remaining second party to establish a communication connection with the conference bridge and terminate a communication connection with the accepting second party.

32. The method according to claim 31 , wherein said steps of having the first party establish a communication connection with the conference bridge and identify each second party to the conference bridge comprise having the first party send an INVITE request message to the conference bridge acting to establish a communication connection between the first party and the conference bridge, the INVITE request message containing an ALSO header field containing each second party, the ALSO header field acting to instruct the conference bridge to establish a communication connection with each second party.