Streaming media subscription mechanism for a content delivery network

• US 6,751,673 B2
• Filed: 01/03/2001
• Issued: 06/15/2004
• Est. Priority Date: 01/03/2001
• Status: Expired due to Term

• Current Assignee: Akamai Technologies, Inc.
• Original Assignee: Akamai Technologies, Inc.
• Inventors: Shaw, David M.
• Primary Examiner(s): Etienne, Ario
• Assistant Examiner(s): SALAD, ABDULLAHI ELMI
• Application Number:
  US09/753,398
• Publication Number:
  US 20020124098A1
• Time in Patent Office: 1,259 Days
• Field of Search: 709/231, 709/238, 709/230, 709/232, 709/203, 709/217, 709/235, 709/223, 709/205, 370/428, 725/87, 725/98
• US Class Current: 709/231
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/612 for unicast
• 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 67/306 User profiles
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A reflector network is used within a content delivery network to enable requesting end users to subscribe to live streams that have been published to CDN entry points. A reflector is a generalized packet router program. The reflector network preferably comprises a hierarchy of reflectors that are located at the various entry points into the CDN, at each edge node at which requesting users may be directed by the CDN to obtain live streams, and at various “reflector” nodes located within at least one intermediate layer (in the hierarchy) between the entry points and the edge nodes. The edge nodes and each reflector node also include a manager program that arranges for feeds. When an end user is directed to an edge node that is not yet receiving the desired stream, the edge node'"'"'s manager issues a subscription request to a set of reflector nodes. If the reflector node(s) are already receiving the desired stream, their reflector(s) begin sending it to the requesting edge node. If, however, the reflector node(s) are not already receiving the desired stream, their manager programs issue the subscription request to the entry point(s) to start the feed.

Claims

1. A subscription mechanism for use in a content delivery network (CDN) having a set of content provider entry points, an intermediate layer of set reflectors, and a set of edge nodes to which requesting end users are selectively directed to obtain live data streams that are published to the CDN, wherein an edge node includes a server for delivering the live data streams to requesting end users, the mechanism comprising:

code operative at the edge node (a) for determining whether the edge node server is already receiving a live data stream being requested by an end user at the time of such a request from the end user; and

(b) for issuing to at least one set reflector a subscription to the live data stream if the edge node server is not already receiving the live data stream, the subscription originating from the edge node; and

code operative at the set reflector for (a) determining whether the set reflector is already receiving the live data stream being requested by the edge node; and

(b) for issuing to a given entry point the subscription to the live data stream if the set reflector is not already receiving the live data stream, the subscription originating from the set reflector.

2. The subscription mechanism as described in claim 1 wherein the edge node also includes code for routing the live data stream received from at least one set reflector to the edge node server.

3. The subscription mechanism as described in claim 1 wherein the set reflector also includes code for routing the live data stream received from the given entry point to the edge node.

4. The subscription mechanism as described in claim 1 further including code operative at the given entry point for routing the live data stream to the set reflector in response to receipt of the subscription.

5. The subscription mechanism as described in claim 1 wherein the code operative at the edge node includes code for determining a preferred set of set reflectors to which the subscription is to be issued.

6. A subscription mechanism for use in a content delivery network (CDN) having a set of content provider entry points, an intermediate layer of set reflectors, and a set of edge nodes to which requesting end users are selectively directed to obtain live data streams that are published to the CDN, wherein an edge node includes a server for delivering the live data streams to requesting end users, the mechanism comprising:

code operative at the edge node (a) for determining whether the edge node server is already receiving a live data stream being requested by an end user at the time of such a request from the end user, (b) for issuing to at least one set reflector a subscription to the live data stream if the edge node server is not already receiving the live data stream, the subscription originating from the edge node, and (c) for routing the live data stream to the edge node server upon receipt of the live data stream from the set reflector;

code operative at the set reflector for (a) determining whether the set reflector is already receiving the live data stream being requested by the edge node, (b) for issuing to a given entry point the subscription to the live data stream if the set reflector is not already receiving the live data stream, and (c) for routing the live data stream to the edge node upon receipt of the live data stream from the given entry point; and

code operative at the given entry point for routing the live data stream to the set reflector in response to receipt of the subscription.

7. The subscription mechanism as described in claim 6 wherein the routing code in the edge node, the set reflector and the given entry point is a UDP packet router.

8. The subscription mechanism as described in claim 6 wherein the server is a streaming media server that delivers streaming media in a given format, wherein the given format is selected from the set of formats consisting of Windows Media, RealSystem and QuickTime.

9. The subscription mechanism as described in claim 6 wherein the code operative at the edge node includes code for determining a preferred set of set reflectors to which the subscription is to be issued.