System and method for streaming media objects

• US 8,230,098 B2
• Filed: 05/10/2006
• Issued: 07/24/2012
• Est. Priority Date: 05/10/2006
• Status: Active Grant

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Chen, Songqing, Guo, Lei, Xiao, Zhen, Zhang, Xiaodong
• Primary Examiner(s): Tiv, Backhean
• Application Number:
  US11/431,681
• Publication Number:
  US 20070266169A1
• Time in Patent Office: 2,267 Days
• Field of Search: 370/389, 370/390, 370/392, 709225-233, 709/238, 709 20-206
• US Class Current: 709/231
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/104 Peer-to-peer [P2P] networks
• CPC Class Codes: H04L 67/1065 Discovery involving distributed pre-established resource-based relationships among peers, e.g. based on distributed hash tables [DHT] pre-configuration of logical or physical connections H04L67/1053
• CPC Class Codes: H04L 67/108 characterised by resources being split in blocks or fragments
• CPC Class Codes: H04L 67/1091 Interfacing with client-server systems or between P2P systems
• CPC Class Codes: H04L 67/1093 Some peer nodes performing special functions
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A method and system for streaming media objects. A streaming system includes a group of end nodes and at least one core node connected via an overlay network. The end nodes cache segments of media objects and stream the media objects to a client segment by segment. Each end node stores segment indices for locating segments cached on end nodes or a core node in the system. The core node is a dedicated proxy which fetches media objects from a remote media server and streams the media objects to a client when the media objects are unavailable from the end nodes.

Claims

1. A method of streaming a requested segment of a media object in a peer-to-peer network having a plurality of nodes including a plurality of end nodes and a core node, the method comprising:

routing a request for the requested segment to a target end node assigned to a key space zone corresponding to the requested segment;

if a segment index of the media object exists at the target end node;

determining that the requested segment is not stored at any of the plurality of end nodes if a location list of the segment index is empty; and

determining that the requested segment is stored at one of the plurality of end nodes if the location list is not empty;

in response to determining that the requested segment is stored at one of the plurality of end nodes, streaming the requested segment of the media object from an end node of the plurality of end nodes at which the requested segment of the media object is stored;

if the segment index does not exist at the target end node, determining that the requested segment is not stored at any of the plurality of end nodes; and

in response to determining that the requested segment is not stored at any of the plurality of end nodes;

retrieving the media object from a remote media server based on a uniform resource locator of the media object via the core node,

determining, at the core node, a plurality of segments of the media object, wherein the plurality of segments includes the requested segment,

storing the segment index at the core node,

streaming the media object from the core node, and

designating the core node as a streaming server for streaming all subsequent requests for the requested segment of the media object,

wherein the remote media server is not in the peer-to-peer network and the core node is a dedicated proxy in the peer-to-peer network between the plurality of end nodes and the remote media server.

2. The method of claim 1, further comprising:

connecting to the remote media server via the core node to fetch the media object;

if the segment index does not exist at the target end node, creating a segment index for the requested segment and storing the segment index at the target end node assigned to a key space zone corresponding to a segment identifier of the requested segment; and

if the segment index does exist at the target end node, storing location information of the core node in the location list of the segment index.

3. The method of claim 1, wherein a request for the requested segment originates from a client, the client being one of the plurality of end nodes.

4. The method of claim 3, further comprising:

searching a local cache for the requested segment;

if the requested segment is not in the local cache, routing a request for the requested segment based on a segment identifier of the requested segment and searching for the segment index corresponding to the segment identifier to determine whether the requested segment is stored at any of the plurality of end nodes and the core node based on the location list.

5. The method of claim 3, further comprising:

storing the requested segment at the client when the requested segment is streamed to the client.

6. The method of claim 5, further comprising:

publishing the requested segment stored at the client in a location list of the segment index.

7. The method of claim 1, wherein further comprising:

publishing the requested segment stored at the core node in the location list of the segment index.

8. The method of claim 7, wherein publishing comprises:

sending an internet protocol address and a port number of the core node to an end node to include the internet protocol address and the port number of the core node in the location list of the segment index.

9. The method of claim 1, wherein streaming comprises:

selecting a node at which a segment has been stored to serve as a serving node;

sending a location of the serving node to a client that requested the segment; and

streaming the segment from the serving node to the client.

10. The method of claim 9, wherein selecting comprises:

retrieving the segment index; and

choosing an end node or the core node from a list of locations included in the segment index.

11. The method of claim 10, wherein choosing comprises:

choosing the end node or the core node in the list of locations with most available bandwidth.

12. The method of claim 1, further comprising:

playing a current segment of the media object when receiving the requested segment from the end node; and

buffering a next segment of the media object when playing the current segment.

13. A streaming system, comprising:

a plurality of nodes in a peer-to-peer network, the plurality of nodes comprising;

a plurality of end nodes, each comprising;

a memory comprising;

segments of media objects and segment indices for locating segments of the media objects;

a subset of a distributed hash table for storing the segment indices having location information of the segments of media objects wherein each segment index comprises a location list which lists each end node or a core node at which a corresponding segment of the media objects is stored, wherein the location list comprises an internet protocol address and a port number for each end node or core node at which the corresponding segment of the media objects is stored; and

segment indices of the segments having segment identifiers;

wherein each end node is assigned a key space zone and stores the segment indices of the segments having segment identifiers corresponding to the key space zone;

means for streaming requested segments of the media objects to a client;

means for searching the memory for a segment index corresponding to the requested segments of the media objects;

means for selecting an end node or the core node listed in the location list of corresponding segments to be used to stream the requested segments; and

means for routing a location of the end node or the core node to the client; and

a core node that is a dedicated proxy between the plurality of end nodes and a remote media server that is not in the peer-to-peer network, the core node comprising;

means for fetching the media objects from the remote media server based on a uniform resource locator of the media objects and storing the segment indices for locating the requested segments of the media objects when the requested segments are not stored at any of the plurality of end nodes,

means for indicating that the core node is a streaming server for streaming all subsequent requests for the requested segments of the media objects, and

means for streaming the media objects.

14. The streaming system of claim 13, wherein each end node further comprises:

means for routing a request for a segment not stored at that end node to a target end node, which is an end node assigned to the key space zone corresponding to a segment identifier of the segment.