Abstract: A communication terminal (1) on a transmission side comprises means (1-10) for detecting congestion, means (1-7) for detecting a sign of congestion with reference to an ideal congestion window size and a current congestion window size, means for estimating a ratio of priority traffic with respect to traffic within a network, and means (1-8) for dynamically changing a threshold value for detection of the sign of congestion in response to the estimated ratio. When the congestion or the sign of congestion is detected, a congestion window size is changed into the idea congestion window size.

Abstract: In a communication system for transmitting and receiving data between a plurality of terminals via a network through a session relay for relaying communication between the terminals, each of the terminals or the session relay measures a one-way or a round-trip delay time in the network, determines a threshold delay time at which network congestion is judged. With reference to a delay time upon detection of packet loss and the threshold delay time, estimation is made about the possibility that the packet loss results from congestion. A congestion window is changed with reference to the possibility upon detection of the packet loss.

Abstract: A method and apparatus for congestion control of a Transmission Control Protocol (TCP) connection. A TCP source monitors received acknowledgments (ACKs) and uses header information associated with the ACKs to determine an amount of data delivered at a TCP receiver. The amount of delivered data, divided by the time requited to deliver the data, gives a measure of instant data rate. The instant data rate is input to a filtering and averaging process to generate an estimate of the end-to-end bandwidth share or data rate of the connection. For the entire duration of the connection, the TCP source updates its estimate of the end-to-end bandwidth share every time an ACK is received. The estimate of the end-to-end bandwidth share is used the reset a congestion window and a slow start threshold whenever packet loss is indicated such as whenever a timeout expires or whenever three (3) duplicate ACKs are received.

Abstract: Methods and apparatuses for improved data transmission control protocols. Acknowledgment streams are used by a sender process to generate various estimates of eligible transmission rates that are fair to other processes competing for bandwidth across a common network. In addition, the acknowledgment streams are used in conjunction with various other standard transmission control protocol metrics to adapt a filter for use on the rate estimates. Additional improvements in throughput may no be had by measuring the overall capacity of the computer network using packet pair dispersion measurements and adaptive network probing. In addition, the methods may be adapted for both packet transmission and video streaming applications.

Abstract: In a communication system for transmitting and receiving data between a plurality of terminals via a network through a session relay for relaying communication between the terminals, each of the terminals or the session relay measures a one-way or a round-trip delay time in the network, determines a threshold delay time at which network congestion is judged. With reference to a delay time upon detection of packet loss and the threshold delay time, estimation is made about the possibility that the packet loss results from congestion. A congestion window is changed with reference to the possibility upon detection of the packet loss.

Abstract: A communication terminal (1) on a transmission side comprises means (1-10) for detecting congestion, means (1-7) for detecting a sign of congestion with reference to an ideal congestion window size and a current congestion window size, means for estimating a ratio of priority traffic with respect to traffic within a network, and means (1-6) for dynamically changing a threshold value for detection of the sign of congestion in response to the estimated ratio. When the congestion or the sign of congestion is detected, a congestion window size is changed into the idea congestion window size.

Abstract: A method and apparatus for congestion control of a Transmission Control Protocol (TCP) connection. A TCP source monitors received acknowledgments (ACKs) and uses header information associated with the ACKs to determine an amount of data delivered at a TCP receiver. The amount of delivered data, divided by the time requited to deliver the data, gives a measure of instant data rate. The instant data rate is input to a filtering and averaging process to generate an estimate of the end-to-end bandwidth share or data rate of the connection. For the entire duration of the connection, the TCP source updates its estimate of the end-to-end bandwidth share every time an ACK is received. The estimate of the end-to-end bandwidth share is used the reset a congestion window and a slow start threshold whenever packet loss is indicated such as whenever a timeout expires or whenever three (3) duplicate ACKs are received.

Abstract: Fault tolerant topology for passive optical networks essentially based on a "tree configuration" with branch points or nodes (16, 17) made up of passive optical splitters, in which each node (16, 17) of a specific level is connected to the same number of nodes (16, 17) of the level immediately below by two or more branches (Rd, Rs) and a supplementary connection (S1, S2 . . . ) is provided between each pair of nodes of the same level (FIG. 1).