Hitachi, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Nobuhiko Ido

Michio Suzuki

Ryoichi Sasaki

Tsutomu Nakamura

Toshiya Oouchi

Tomoaki Tsunoda

Kazuhiko Haru

Kohsuke Shinnai

Hiroyuki Fujitani

Hiroto Uno

Keiko Kuroda

In an ATM switching network, a limitation of traffic in an ATM switching apparatus is relaxed. In an ATM switching network capable of allocating a plurality of communication channels to a terminal unit of one subscriber, when the terminal of this subscriber requests setting of the plural communication channels, a traffic amount of the communication channels proposed to the ATM switching apparatus is declared as a total amount of the respective communication channels. The ATM switching apparatus measures a total traffic amount of the plural communication channels set in response to the request made by the terminal unit, and limits the traffic of the plural set communication channels in such a manner that the measured traffic amount becomes lower than, or equal to the traffic amount declared through the terminal unit. The subscriber terminal unit can increase the traffic of the respective communication channels within such a range that a total traffic amount during transmission does not exceed the proposed traffic amount.

ATM switching network for setting plural communication channels among

In a packet communication network in which a plurality of subscriber's lines are connected with a packet switching unit via a multiplexer and each of terminal units declares the packet rate on call request, a packet rate monitoring circuit is provided between the packet switching unit and the multiplexer. The packet rate monitoring circuit includes a circuit for monitoring the cell arrival rate, a circuit for detecting a packet cell violating the declared value which is transmitted from the terminal, a circuit for adding a mark representative of the violation cell to the violation packet which is detected by the detecting circuit, and a circuit for automatically modifying the declared parameter. The modifying circuit applies the declare parameter which was automatically modified in accordance with utilization condition (the number of multiplexings and the line utilization) of the multiplexer disposed between the subscriber's terminals and the rate monitoring circuit so that the detecting circuit detects the violation packets based upon the modified declared parameter.

Method of and system for monitoring packet rate in packet network

A network management system prepares an optimum configuration table corresponding to a failure of a transit trunk and distributes the same to each TDM, and thereby the optimization of reconfiguration of a high-speed digital network is enabled. User data are transmitted and received in accordance with route information table defined beforehand in each TDM. On the other hand, network management information is sent to all trunks other than a receiving trunk for the managing information when flooding is designated by the network management system. Accordingly, the management information can be sent without fail if any route to the TDM to be supplied with the management information exists. When source-routing is designated, the communications of the managing information can be implemented efficiently, since the route is set by the management information. Moreover, each packet exchanger provides route identifiers defined individually for correspondence to local trunks, and transit route information set in each packet is recorded by using the route identifiers of each packet exchanger. Route information determined in the flooding process is then used in subsequent source-routed communications.

Network control method and apparatus therefor

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Yokohama, Japan

Nobuhiko Ido