Monitoring and correcting upstream packet loss

Abstract

An upstream error controller monitors a media stream at a location upstream from an associated set of receivers receiving the media stream. The upstream error controller sends out suppression notices for any media packets lost upstream causing the receivers to suppress sending lost packet notices. In another embodiment, a repair point joins a primary multicast group with multiple receivers for receiving a native media stream. The repair point also joins a second multicast group receiving multicast backup data for retransmitting or repairing the native media stream that does not include an associated set of receivers. In yet another embodiment, the upstream error controller is used in combination with a hybrid packet repair scheme for adaptively switching among unicast retransmission, multicast retransmission, and Forward Error Correction (FEC).

1 . An apparatus, comprising:
 one or more processors; and   a memory coupled to the one or more processors comprising instructions executable by the processors, the processors operable when executing the instructions to:   monitor a media stream at a location upstream from an associated set of receivers receiving the media stream;   identifying media packets in the media stream lost upstream of the associated set of the receivers; and   sending out suppression notices to the associated set of receivers that keep the associated set of receivers from sending back lost packet notices.   
   
   
       2 . The apparatus according to  claim 1  wherein the one or more processors monitoring the media stream are not located in a direct media stream path between a media stream server and the receivers and wherein the one or more processors use a repair path separate from the media stream for sending the suppression notices. 
   
   
       3 . The apparatus according to  claim 1  wherein the one or more processors:
 identify either a block outage for a group of lost media packets or identify individual outages for individual lost media packets;   send a block suppression notice for the identified block outage that cause the receivers to suppress all lost packet notices for some period of time; and   send individual suppression notices for the identified individual outages that cause the receivers to only suppress lost packet notices associated with the individual lost media packets.   
   
   
       4 . The apparatus according to  claim 1  wherein the one or more processors:
 receive a backup data stream separate from the media stream that is not sent to the receivers; and   send out packets from the backup data stream to the receivers for repairing or replacing the lost packets from the media stream.   
   
   
       5 . The apparatus according to  claim 4  wherein the backup data stream includes either a second redundant media stream or Forward Error Correction (FEC) packets for correcting the media stream. 
   
   
       6 . The apparatus according to  claim 1  wherein the one or more processors track a number of lost upstream packets lost upstream of a network monitoring location above a particular associated group of receivers and also track a number of lost downstream packets lost downstream of the network monitoring location, the one or more processors then sending different retransmission packets or Forward Error Correction (FEC) packets to the receivers according to a pattern or number of lost upstream packets and a pattern or number of lost downstream packets. 
   
   
       7 . The apparatus according to  claim 1  wherein the one or more processors:
 receive lost packet notices that identify downstream packets lost in a downstream portion of a network;   update a lost packet table to reflect the number of lost packet notices; and   dynamically select different types of correction or retransmission schemes for correcting or replacing the lost downstream packets according to the lost packet table.   
   
   
       8 . The apparatus according to  claim 7  wherein the one or more processors:
 dynamically identify a general number of receivers actively receiving the media stream;   identify when upstream packets in an upstream portion of the network are lost;   send out suppression notices that keep the receivers from sending back lost packet notices for the identified upstream packets;   update the lost packet table to reflect the number of lost packet notices that would have normally been received from the identified general number of receivers if not for the suppression notices; and   dynamically selecting different types of correction or retransmission schemes for correcting or replacing the lost upstream packets and lost downstream packets according to the lost packet table.   
   
   
       9 . The apparatus according to  claim 1  wherein:
 the media stream is transmitted in a Real Time Protocol (RTP) session; and   the one or more processors are associated with a Real Time Control Protocol (RTCP) feedback address for the RTP session and multicast the suppression notices as Real Time Control Protocol (RTCP) messages.   
   
   
       10 . An apparatus, comprising:
 computer processing logic configured to receive a media stream, detect lost packets in the media stream, and send lost packet notifications to a repair point identifying the detected lost packets; and   the computer processing logic further configured to suppress the lost packet notifications that would have been normally been sent when the lost packets are detected responsive to received suppression messages received on a separate repair channel.   
   
   
       11 . The apparatus according to  claim 10  wherein the computer processing logic stops sending the lost packet notifications for any detected lost packets when the suppression messages identify a complete outage of the media stream. 
   
   
       12 . The apparatus according to  claim 10  wherein the computer processing logic stops sending the lost packet notifications only for specific lost packets identified by the suppression messages. 
   
   
       13 . The apparatus according to  10  wherein the computer processing logic uses error correction packets or retransmission packets received from the repair point to recreate or replace the lost packets. 
   
   
       14 . The apparatus according to  claim 10  wherein the computer processing logic establishes a Real Time Protocol (RTP) session with a media server for receiving the media stream, and establishes a separate Real Time Control Protocol (RTCP) session with the repair point for both sending the lost packet notifications and receiving back the suppression messages. 
   
   
       15 . A method, comprising:
 joining a primary multicast group with multiple receivers for receiving a native media stream;   joining a second multicast group that does not include a significant fraction of an associated set of receivers for receiving backup data for the native media stream;   identifying lost packets in the native media stream;   identifying the backup data associated with the identified lost packets; and   multicasting the identified backup data to the receivers in the primary multicast group for repairing the lost packets in the native media stream.   
   
   
       16 . The method according to  claim 15  including:
 identifying a general number of receivers actively receiving the media stream;   receiving lost packet notices from the receivers that identify downstream packets lost in a downstream portion of a network:   updating a lost packet table to reflect the number of lost packet notices received from the receivers;   identifying upstream packets lost in an upstream portion of the network;   sending out suppression notices for the identified lost upstream packets that keep the receivers from sending back lost packet notices;   updating the lost packet table to reflect the number of lost packet notices that would have normally been received from the receivers if the suppression notices were not sent; and   dynamically selecting different types of correction or retransmission schemes for correcting or replacing the lost upstream packets and the lost downstream packets according to the lost packet table.   
   
   
       17 . The method according to  claim 15  including sending out suppression messages that cause the receivers in the primary multicast group to suppress sending lost packet notices for packets lost in the native media stream. 
   
   
       18 . The method according to  claim 17  including multicasting the suppression messages to all of the receivers that are members of the primary multicast group over a repair channel separate from the native media steam. 
   
   
       19 . The method according to  claim 16  including:
 sending complete outage suppression messages when the entire native media stream is disrupted that cause to the receivers to suppress sending any lost packet messages; and   sending specific packet suppression messages that cause the receivers to only suppress sending lost packet messages for identified lost media packets.   
   
   
       20 . The method according to  claim 15  including:
 tracking a number or pattern of packets lost in the native media stream;   sending out Forward Error Correction (FEC) packets to the receivers when the number or pattern of lost packets is more efficiently corrected by the receivers using FEC; and   sending out retransmissions of the lost packets when the number or pattern of lost packets is more efficiently corrected by retransmitting the lost packets.