Method for optimizing data transfer in a data network

Abstract

The present invention relates to a method for optimizing data flow in a data network. Data that is to be transferred across the network at a constant bitrate is handled differently by a Transmission Control Protocol (TCP) layer compared to other data. A TCP congestion control process is adapted to recognize whether data packets from an application are to be transferred across the data network at a constant bitrate. The constant bitrate channel may be recognized by a Quality of Service identifier or a TCP port number. If the data packets do belong to the constant bitrate channel, the TCP congestion control limits the congestion window for these data packets. The congestion window for data packets other than those in the constant bitrate channel is allowed to increase, as usual, until data packets are lost, at which point the congestion window is reduced to a maximum segment size. The congestion window for constant bitrate packets, however, is increased until it reaches a maximum value. The limiting value of the congestion window is the constant bitrate multiplied by the round trip delay time between sending a packet and receiving its acknowledgement. The modifications to the TCP process may provide for the transmission of constant bitrate data over the data network that does not experience a timeout.