Method and apparatus for analyzing a media path in a packet switched network

• US 7,729,267 B2
• Filed: 11/26/2003
• Issued: 06/01/2010
• Est. Priority Date: 11/26/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wing, Daniel G., Oran, David R.
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): Yuen; Kan
• Application Number:
  US10/723,118
• Publication Number:
  US 20060034188A1
• Time in Patent Office: 2,379 Days
• Field of Search: 370/241, 370/241.1, 370/248, 370/249, 370/251, 370/252, 370/253, 370/238, 709/230
• US Class Current: 370/252
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/80 Responding to QoS

Abstract

No-op media payload packets are used to analyze a media path in a packet switched network. In one embodiment, the no-op packets are Real Time Protocol (RTP) payload packets that contain no media content. A Real Time Control Protocol (RTCP) report is generated for the received RTP no-op packets. A marker bit is set in one of the no-op packets that triggers the no-op packet receiver to send back the RTCP report. The media steam is transmitted when the statistics in the RTCP report indicate a viable media path.

Claims

1. A method for analyzing a media path in a packet switched network, comprising:

conducting an initial media call signaling session with logic circuitry for establishing a media call and setting up the media path over the packet switched network, the media path established by successful completion of the initial media call signaling setup session and used for receiving or transmitting media packets containing media payloads;

sending and/or receiving one or more no-op media payload packets over the media path with the logic circuitry during and within the initial media call signaling session prior to establishing the media call and setting up the media path, the no-op media payload packets formatted as though the media packets contain media payloads but the no-op media payload packets formatted without media payloads and not containing media payloads;

requesting or receiving media path quality information with the logic circuitry associated with the no-op media payload packets during the initial media call signaling session prior to establishment of the media call being established by the initial media call signaling session;

selectively completing or terminating the initial media call signaling session with the logic circuitry according to the information obtained from the transmission of the no-op media payload packet during the initial media call signaling session, successful completion of the initial media call signaling session enabling subsequent transmission or playing out of media packets containing media payloads over the media path; and

inserting a time stamp into the transmitted no-op media payload packets with the logic circuitry that identifies a non-zero amount of simulated media time for media content in the no-op media payload packets that is not actually encoded into the no-op media payload packets.

2. A method according to claim 1 including formatting the no-op media payload packets as a Real Time Protocol (RTP) media payload packet that is formatted as though it contains media content but that contains no media content and sending the no-op media payload packets during a Session Initiation Protocol (SIP) media call signaling session.

3. A method according to claim 1 generating a media path analysis report from the information generated from the transmitted no-op media payload packets.

4. A method according to claim 3 wherein the media path analysis report is a Real Time Control Protocol (RTCP) report.

5. A method according to claim 3 including setting a marker bit in the no-op media payload packets to initiate a receiver to immediately send back the media path analysis report.

6. A method according to claim 5 including determining whether or not to transmit a media stream over the media path according to when or if the media path analysis report is received after transmitting the no-op media payload packets with the set marker bit.

7. A method according to claim 3 including generating the media path analysis report without playing out contents of the no-op media payload packets.

8. A method according to claim 3 including:

receiving multiple no-op media payload packets during the same media call signaling session; and

generating the media path analysis report according to transmission information for all of the multiple no-op media payload packets.

9. A method according to claim 1 including notifying a user of a media call according to the information associated with the transmission of the no-op media payload packets.

10. A network processing device, comprising:

a processor configured to;

conduct an initial media call signaling session for establishing a media call and setting up a media path over a packet switched network;

send and/or receive one or more no-op media payload packets over the media path during the initial media call signaling session, the no-op media payload packets formatted as though the media packets contain media payloads but the no-op media payload packets formatted without media payloads;

selectively complete or terminate the initial media call signaling session according to information obtained from transmission of the no-op media payload packet during the initial media call signaling session, wherein successful completion of the initial media call signaling session enables subsequent transmission or playing out of media packets containing media payloads over the media path; and

insert a time stamp into the no-op media payload packets that identifies a non-zero amount of simulated media time for media content in the media payload that is not actually encoded into the media payload of the packets.

11. The network processing device according to claim 10 wherein the processor is configured to generate a Real Time Control Protocol (RTCP) report using the information obtained from transmission of the no-op media payload packets.

12. The network processing device according to claim 10 including a user interface configured to communicate with a device that initiates an Internet Protocol network connection for transmitting the media packets.

13. The network processing device according to claim 10 wherein the initial media call signaling session notifies a receiver that the no-op media payload packets are going to be used for analyzing the packet switched network.

14. The network processing device according to claim 13 wherein the processor is configured to generate a marker bit in one of the no-op media payload packets that causes the receiver to send back the information obtained from transmission of the no-op media payload packets.

15. The network processing device according to claim 10 wherein the processor is configured to send or receive the media packets according to a number of successfully transmitted no-op media payload packets and the jitter statistics for the no-op media payload packets.

16. A method for analyzing a media path in a packet switched network, comprising:

initiating a Real Time Protocol (RTP) signaling session with a network processing device for establishing a media path for transporting RTP payload packets that contain media payloads;

sending multiple RTP payload packets with the network processing device during and within the RTP signaling session that are formatted as if the RTP payload packets contain a media payload but the RTP payload packets are formatted without media payloads and do not contain any media payload;

selectively completing or terminating the RTP signaling session with the network processing device according to information obtained by sending the RTP payload packets during the RTP signaling session, wherein successful completion of the RTP signaling session enables subsequent transmission or playing out of RTP packets containing media payloads over the media path; and

inserting a time stamp into the transmitted RTP payload packets with the network processing device that identifies a non-zero amount of simulated media time for media content in the RTP payload packets that is not actually encoded into the RTP payload packets.

17. The method according to claim 16 including:

receiving multiple RTP payload packets that contain no media payload;

generating a Real Time Control Protocol (RTCP) report that includes media path information for the received RTP payload packets;

sending the RTCP report when one of the RTP payload packets is received that has a set marker bit; and

establishing a media stream according to the media path information in the RTCP report.

18. The method according to claim 17 including delaying ringing a phone used for receiving a media stream until the RTCP report is received and indicates an acceptable media path for sending the media stream.