Method and system for fault tolerant media streaming over the internet

• US 6,665,726 B1
• Filed: 01/06/2000
• Issued: 12/16/2003
• Est. Priority Date: 01/06/2000
• Status: Expired due to Term

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Shaw, David, Leighton, F. Thomson, Lewin, Daniel M., Maggs, Bruce
• Primary Examiner(s): CALDWELL, ANDREW T
• Application Number:
  US09/478,571
• Time in Patent Office: 1,440 Days
• Field of Search: 709/219, 709/231, 709/204-205, 725/87, 725/98-99, 714/2
• US Class Current: 709/231
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/613 for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/65 Network streaming protocols, e.g. real-time transport protocol [RTP] or real-time control protocol [RTCP]
• CPC Class Codes: H04L 65/70 Media network packetisation
• CPC Class Codes: H04L 65/765 intermediate
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/26616 for merging a unicast channel into a multicast channel, e.g. in a VOD application, when a client served by unicast channel catches up a multicast channel to save bandwidth data multicast over packet-switching network H04L12/18

Abstract

A replication process to provide fault tolerance for a streaming signal in a computer network. In one embodiment, the original or source signal is sent to several splitters which, in turn, each make copies of the signal and send the copies into a second layer of devices, which are referred to as “concentrators.” A given concentrator receives as input one or more copies of the source signal. In a preferred embodiment, a given concentrator receives two copies of the source signal from at least two different splitters. The concentrators process the incoming streaming signal copies, for example, by merging them into a single or composite copy of the original source signal according to a given processing algorithm. The output of a given concentrator may then be fed into a splitter, with the process then being repeated if desired to make an arbitrary large number of copies of the signal. At the end of the replication process, the output of a splitter or a concentrator is fed directly or indirectly to an end user. The replication process is fault-tolerant, and thus the end user'"'"'s signal is not interrupted regardless of signal or equipment problems within the distribution mechanism.

Claims

1. An online content distribution system, comprising:

a signal source;

a set of splitters, each of which receive the signal source and generate a copy thereof, wherein a given splitter includes means for encoding a copy of the signal source;

a set or concentrators, each of the set of concentrators receiving, from two or more splitters, two or more streams or the signal source, wherein a given concentrator includes means for decoding a copy of the signal source encoded by the given splitter;

each of the concentrators including means for concentrating the two or more streams of the signal source into a composite signal.

2. The online content distribution system as described in claim 1 wherein the means for concentrating comprises code for:

determining whether a given packet of the signal source has been forwarded from the concentrator;

if the given packet of the signal source has not been forwarded, outputting, in the composite signal, the given packet; and

if the given packet of the signal source has been forwarded, discarding the given packet.

3. The online content distribution system as described in claim 1 wherein the means for concentrating comprises code for:

buffering each of the two or more streams;

at a given time, identifying a given packet in the two or more streams; and

forwarding the given packet from the concentrator as part of the composite signal.

4. The online content distribution system as described in claim 3 wherein the given packet is an earliest packet with the signal source stream.

5. The online content distribution system as described in claim 3 wherein the means for concentrating code:

reorders given packets in a signal source stream prior to outputting the composite signal from the concentrator.

6. The online content distribution system as described in claim 1 wherein the signal source comprises a media stream.

7. The online content distribution system as described in claim 6 wherein the media stream is formatted for rendering in a media player associated with a client browser.

8. The online content distribution system as described in claim 2 wherein the signal source stream conforms to a given streaming protocol.

9. The online content distribution system as described in claim 8 wherein the given protocol is RTSP.

10. The online content distribution system as described it claim 1 wherein the means for encoding and the means for decoding utilize an information dispersal algorithm.

11. The online content distribution system as described in claim 1 wherein the signal source streams are delivered via a given protocol.

12. The online content distribution system as described in claim 11 wherein the given protocol is UDP.