Abstract: A dynamic technique for routing data packets between entry and destination nodes of a multi-node communication network of arbitrary topology In accordance with this technique, the nodes of the network are connected together by a multitude of links, and a subset of these links form a virtual ring embedded in the network and traversing each node thereof at least once. The nodes route each data packet to a destination node without requiring any data from the data packet other than data identifying the destination node of the data packet. Also, the nodes route each data packet to its destination node such that the distance, along the virtual ring, between the data packet and its destination node always decrease. Data packets in the virtual embedded ring have priority to continue to be routed on the ring. As a result, lossless routing with a single buffer per each input link is provided.

Abstract: A two-phase fairness algorithm for regulating the transmission of data packets in a communication network having a multitude of nodes connected together to form a spanning tree. In a first or broadcast phase of the fairness algorithm, a first control signal is transmitted over the spanning tree from a root node or a root edge of the tree. This first control signal indicates to each node of the tree a first number of data packets that the node is permitted to transmit in a corresponding time interval. Each intermediate node of the tree transmits the first signal to each of its children nodes only when one or more various conditions relating to the transmission of data packets are satisfied. In a second or merge phase of the fairness algorithm, a second control signal is transmitted from the leaves of the tree to the root node or root edge of the tree.

Abstract: A method and apparatus for controlling the transmission of a first class of traffic which is transmitted on a ring network with a second class of traffic. This invention provides for the transmission of a first control signal where both classes of traffic may be transmitted on the ring if current protocols permit. This first control signal will be changed to a second control signal if, after the first control signal is transmitted at least once around the network, the first control signal reaches a station having a backlog of second class traffic. The second control signal is transmitted once around the ring network to indicate to each station that it may not transmit the first class traffic. The first class of traffic is usually asynchronous data, while the second class of traffic is usually synchronous data.

Abstract: A method of discarding unwanted data packets from a communication network of the type having a multitude of nodes connected together to form a circular network. Each node has an address, and each data packet includes a plurality of address subfields to identify addresses of one or more of said nodes. The method comprises the steps of dividing the network into a plurality of segments such that each of the network segments is adjacent at least another of the network segments, assigning each of the network segments one of a plurality of subspace values such that adjacent network segments have different subspace values, and assigning to each address subfield one of the plurality of subspace values.

Abstract: The invention describes a method for transmitting data on a full-duplex buffer insertion ring. Access to the ring by each node is regulated by circulating control message around the ring. The message indicated to each node the maximum number of packets that it may transmit during the interval from the reception of one control message to the forwarding of a subsequent control message. With this invention a station need not be in possession of the control message in order to transmit a packet. A node will also hold a control message if it has not transmitted a predetermined minimum number of packets in its output buffer in a given time interval.

Abstract: A system for serial communications is disclosed comprising an encoder for serially outputting conservative encoded codewords responsive to a parallel data input, and a decoder for outputting, in parallel, decoded data words responsive to the serially transmitted conservative encoded codewords.The codewords are characterized in that the ratio is known between the total number of bits per codeword transmitted and the total number of transitions per codeword.The encoder transforms each m-bit parallel data work into one n-bit codeword, where n is greater than m, such that every codeword has a known number of transitions and such that one of the transitions in the codeword has a predefined position.Thereafter, the encoder converts each n-bit codeword from parallel to serial form for output onto a serial communications channel.A method is taught for conservative encoding as follows.First, identify and define the total set of q different datawords of m-bits each which can be transmitted.