Internet-Based Video Delivery System

Abstract

A system and method for delivering content over the Internet from a content source to a destination is disclosed which includes the use of an overlay network, built on an underlying IP network. Additionally, error correction capability is added to the overlay network to allow the destination to reconstitute packets lost during the transmission over the Internet. In one embodiment, an overlay network is created using a plurality of overlay nodes, which may be geographically distributed. Each respective content source or destination is also a part of the overlay network. Overhead, capable of providing error correction capability, is added to the content flow as it enters the overlay network. As the content flow leaves the overlay network, this overhead is removed from the content flow. In the case of transmission errors across the overlay network, the overhead information is used to reconstitute lost or corrupted packets.

What is claimed is: 
     
         1 . A system for delivering time-sensitive content across the Internet, comprising:
 an overlay network, comprising one or more overlay nodes;   a transmitting appliance, comprising:
 a packet formation block to create original packets from an incoming content stream; 
 a coding block to create redundant packets which allow reconstruction of original packets in the event of a packet loss, said original packets and said redundant packets defining a set of packets; 
 a transmission block to transmit said set of packets to a first of said overlay nodes; and 
   a receiving appliance, comprising:
 an input block to receive packets from one of said overlay nodes in said overlay network; 
 a packet deconstruction block to properly sequence said received packets; 
 a coding block to reconstruct said original packets from said received packets in case of a loss of one or more packets in said transmitted set of packets; and 
 an output block which transmits said reconstructed original packets to a decoder. 
   
     
     
         2 . The system of  claim 1 , wherein said coding block in said transmitting appliance and said coding block in said receiving appliance utilize forward erasure correction. 
     
     
         3 . A method of transmitting content over the internet between a content provider and a destination, comprising:
 receiving content from said content provider, where said content is divided into a set of original packets;   creating redundant packets based on said original packets;   transmitting said original packets and said redundant packets over an overlay network;   receiving packets transmitted over said overlay network from said content provider;   reconstructing said original packets based on said received packets; and   delivering said reconstructed packets to said destination.   
     
     
         4 . The method of  claim 3 , wherein said redundant packets are constructed using forward erasure correction. 
     
     
         5 . The method of  claim 3 , wherein said overlay network comprises at least one intermediate node disposed between said content provider and said destination. 
     
     
         6 . The method of  claim 5 , wherein said transmitted packets are sent to said intermediate node, and said intermediate node forwards said packets to said destination. 
     
     
         7 . The method of  claim 6 , wherein said intermediate node does not perform said reconstructing step. 
     
     
         8 . The method of  claim 6 , wherein said intermediate node requests retransmission of any missing packets.