Abstract: A repeater such as an Internet router device used in a communication network such as the Internet. The delay time from a device of a sender to a device of a receiver is secured. A communication system, a control circuit, a connecting means, and a computer program are also disclosed. The sending time intervals between sending to a transmission network are calculated from a target value of the transfer rate of a packet to be relayed (S202), a target value of the delay time is determined on the basis of the delay time to be secured (S205), and a reference value of the storage capacity used as a criterion for deciding discard of a packet is calculated from the delay time target value and the sending time intervals (S206). Packets are sent out at the calculated sending time intervals, and discard of a packet is judged according to a predetermined method when a packet having a storage capacity above the storage capacity reference value is received.

Abstract: An output port circuit is provided for a router apparatus which routes and transmits a received packet. Each flow is constituted by continuous packets and belongs to a bandwidth-guaranteed class or a best-effort class. A controller controls storage and reading of a packet into and from a storage unit. Upon allocating a basic volume that is a criterion of a memory size stored in the storage unit to each flow to which the packet to be transmitted belongs, the controller manages the basic volume of each flow of the packet belonging to the bandwidth-guaranteed class by individually allocating the basic volume by the memory size required by each flow, and manages the basic volume of each flow of the packets belonging to the best-effort class by collectively allocating the memory size obtained by subtracting a sum of respective basic volumes allocated to the bandwidth-guaranteed class from an entire memory size.

Abstract: An output port circuit is provided for a router apparatus which routes and transmits a received packet. Each flow is constituted by continuous packets and belongs to a bandwidth-guaranteed class or a best-effort class. A controller controls storage and reading of a packet into and from a storage unit. Upon allocating a basic volume that is a criterion of a memory size stored in the storage unit to each flow to which the packet to be transmitted belongs, the controller manages the basic volume of each flow of the packet belonging to the bandwidth-guaranteed class by individually allocating the basic volume by the memory size required by each flow, and manages the basic volume of each flow of the packets belonging to the best-effort class by collectively allocating the memory size obtained by subtracting a sum of respective basic volumes allocated to the bandwidth-guaranteed class from an entire memory size.

Abstract: A self-routing switching system including a route setting unit (10) which receives transmission information and identification information given from incoming lines and forms, from the identification information, control information for setting a path to one outgoing line to which the transmission information is to be transferred, and a self-routing speech path (20) which can form a plurality of paths and which selects the most suitable one therefrom by the control information and autonomously guides the transmission information to the destination outgoing line.

Abstract: An optical space switch is formed in such a manner that switch elements having two inputs and two outputs are arranged in an n.times.n matrix form and optical signals from n input highways are switched to n output highways. The switch elements are connected in such a manner that the optical signals are always passed through the same number of switch elements, from the input highways to the output highways.

Abstract: A switching system having a tone trunk which stores, in the digital memory thereof, a predetermined digital tone signal in the form of digital codes for supplying the corresponding analog tone signal to telephone sets of subscribers. The digital codes have been coded in such a way that the analog tone signal is accompanied by a quantizing noise having a characteristic of white noise.

Abstract: A switching system having a capability for telecommunication conferences, including therein, at least, a speech path memory, a mixing circuit, and a feedback circuit. The speech path memory is operative to store therein voice data signals provided from subscribers holding a conference. The mixing circuit is operative to mix two voice data signals. The feedback circuit is operative to feed the thus mixed voice data signals back to the speech path memory to accumulate therein each set of the mixed voice data signals for the subscriber's subscriber except each own voice data signal, whereby the subscribers receive respective accumulated voice data signals.