(2012/10/24 12:29), Rodrick Brown wrote:
"With coded TCP, blocks of packets are clumped together and then transformed into algebraic equations that describe the packets. If part of the message is lost, the receiver can solve the equation to derive the missing data.
Don't do that.
MIT found that campus WiFi (2% packet loss) jumped from 1Mbps to 16Mbps. On a fast-moving train (5% packet loss), the connection speed jumped from 0.5Mbps to 13.5Mbps."
If everyone start using TCP with FEC to tolerate 20% of packet loss with 30% FEC overhead, it will make congestion more severe that more than 20% of packets will be dropped and effective speed share of each TCP will be decreased by 30%. The proper approach against lossy liks is to have link local retransmissions or FEC. Masataka Ohta