EXPEDITED RESOURCE NEGOTIATION IN SIP

• US 20120089739A1
• Filed: 10/18/2011
• Published: 04/12/2012
• Est. Priority Date: 05/12/2006
• Status: Active Grant

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Inventors: DRWIEGA, Tadeusz, TELIKEPALLI, Radha
• Granted Patent: US 8,948,186 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: H04L 47/722 at the destination endpoint, e.g. reservation of terminal resources or buffer space
• CPC Class Codes: H04L 47/765 triggered by the end-points
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 69/24 Negotiation of communication capabilities

Abstract

A method of expediting resource negotiation in a modified Session Initiation Protocol (SIP) reduces the number of messages exchanged for resource negotiation, thereby reducing the latencies involved in session setup. The method entails sending an INVITE message having a modified SIP header containing an indication that the originator'"'"'s terminal seeks a fast session setup. The INVITE message further contains a list of all codecs available at the originator'"'"'s terminal and how many each type of media component are required. These codecs can be provided in an order of preference. The answerer selects the codecs for the requested media types from the list of available codecs without engaging in a back-and-forth resource negotiation for the codecs. The result is that the session can be set up with fewer messages which provides quicker session setup than in the prior art.

Claims

1-17. -17. (canceled)

18. A method of operating a communication terminal as an originating terminal to originate a communication session with another communication terminal operating as an answering terminal, the method comprising:

sending to the answering terminal an offer message communicating media capabilities available at the originating terminal and corresponding numbers of media streams; and

receiving from the answering terminal an answer message communicating at least one media capability selected from the media capabilities communicated in the offer message.

19. The method of claim 18, further comprising:

reserving at least one media capability of the originating terminal before sending the offer message; and

releasing from reservation at the originating terminal any unselected media capability on receipt of the answer message communicating the selected at least one media capability.

20. The method of claim 18, wherein the offer message comprises a list of media capabilities in order of preference.

21. The method of claim 18, wherein the offer message comprises an INVITE message.

22. The method of claim 21, wherein the INVITE message comprises a modified session description protocol message.

23. The method of claim 18, wherein the offer message is a 1XX message.

24. The method of claim 18, wherein the offer message comprises a list of media capabilities in order of preference.

25. A method of operating a communication terminal as an answering terminal, to set up a communication session with another communication terminal operating as an originating terminal, the method comprising:

receiving from the originating terminal an offer message communicating media capabilities available at the originating terminal and corresponding numbers of media streams;

selecting at least one media capability based on the communicated media capabilities available at the originating terminal and corresponding numbers of media streams; and

sending from the answering terminal to the originating terminal, an answer message communicating the selected at least one media capability.

26. The method of claim 25, further comprising reserving at least one resource corresponding to the selected at least one media capability.

27. The method of claim 25, wherein the answer message communicates media capabilities selected for at least one media stream.

28. The method of claim 25, wherein the answer message communicates media capabilities supported by the answering terminal and corresponding numbers of media streams.

29. The method of claim 25, wherein the answer message is a 1XX message.

30. A communication terminal operable as an originating communication terminal, the communication terminal comprising a session initiation protocol user agent operable:

to send to an answering communication terminal an offer message communicating media capabilities available at the originating communication terminal and corresponding numbers of media streams; and

to receive from the answering communication terminal an answer message communicating at least one selected media capability.

31. The communication terminal of claim 30, wherein the user agent is further operable:

to reserve at least one media capability of the originating terminal before sending the offer message; and

to release from reservation at the originating terminal any unselected media capability on receipt of the answer message communicating the selected at least one media capability.

32. The communication terminal of claim 30, wherein the offer message comprises a list of media capabilities in order of preference.

33. The communication terminal of claim 30, wherein the offer message comprises an INVITE message.

34. The communication terminal of claim 33, wherein the INVITE message comprises a modified session description protocol message.

35. The communication terminal of claim 30, wherein the offer message is a 1XX message.

36. A communication terminal operable as an answering terminal, the communication terminal comprising a session initiation protocol user agent operable:

to receive from an originating terminal an offer message communicating media capabilities available at the originating communication terminal and corresponding numbers of media streams;

to select at least one media capability based on the communicated media capabilities available at the originating terminal and corresponding numbers of media streams; and

to send from the answering terminal to the originating terminal, an answer message communicating the selected at least one media capability.

37. The communication terminal of claim 36, wherein the user agent is further operable to reserve at least one resource corresponding to the selected at least one media capability.

38. The communication terminal of claim 36, wherein the answer message communicates media capabilities selected for at least one media stream.

39. The communication terminal of claim 36, wherein the answer message communicates media capabilities supported by the answering terminal and corresponding numbers of media streams.