Abstract: A packet network node and method of operating a packet network node are disclosed. Conventional packet network nodes react to congestion in the packet network by dropping packets in a manner which is perceived by users to be indiscriminate. In embodiments of the present invention, communication sources precede communications with a start packet which contains a communication identifier also carried within subsequent packets of the communication. The packet network node makes an entry in a vulnerable communications table (6.4) on receipt of such a start packet. After an amount of time, and often before the cessation of a communication, such entries are removed from the vulnerable communications table. On the onset of congestion, the packet network node disclosed herein deletes packets in communications identified in the vulnerable communications table.

Abstract: In a broadband switching system for the switching of asynchronously transferred cells of data, a dynamic bandwidth controller (DBC) controls the application of data cells at an input port of the system, the data cells being supplied by a number of transmitting end-stations. The DBC detects incoming cells, identifies the source of the cells, provides buffering for the cells, and controls the output of the cells to the system switches according to a current cell rate (CR) assigned to the cells from the respective source. The system also includes a connection admission (CAC) module which determines bandwidth available in the system. The DBC and CAC operate together to maintain a permanent virtual path of a predetermined minimum bandwidth through the system and allocate additional bandwidth on demand up to a maximum. The additional bandwidth allocated to the path can be automatically removed or reduced of it is not used by the source.

Abstract: A packet network node and method of operating a packet network node are disclosed. Conventional packet network nodes react to congestion in the packet network by dropping packets in a manner which is perceived by users to be indiscriminate. In embodiments of the present invention, communication sources precede communications with a start packet which contains a communication identifier also carried within subsequent packets of the communication. The packet network node makes an entry in a vulnerable communications table (6.4) on receipt of such a start packet. After an amount of time, and often before the cessation of a communication, such entries are removed from the vulnerable communications table. On the onset of congestion, the packet network node disclosed herein deletes packets in communications identified in the vulnerable communications table.

Abstract: In a broadband switching system for the switching of asynchronously transferred cells of data, a dynamic bandwidth controller (DBC) controls the application of data cells to an input port of the system. The data cells are supplied by a number of transmitting end-systems. When an end-system begins transmitting data cells, the DBC detects the presence of incoming cells and requests bandwidth from a connection admission control (CAC) forming part of the system. The switching system stores a table associating a number of signal sources connected to the input port with respective predetermined maximum transmission times and maximum transmission rates for the sources. When arrival of cells at the input port from one of the source is detected, the DBC and CAC operate together to allocate sufficient bandwidth in the switching system to allow the respective message size to be transmitted within the respective maximum transmission time. A guaranteed minimum rate of transmission is also guaranteed for the source.

Abstract: In a broadband switching system for the switching of asynchronously transferred cells of data, a dynamic bandwidth controller (DBC) controls the application of data cells to an input port of the system. Data cells are supplied by a number of transmitting end-systems. When an end-system begins transmitting data cells, the DBC detects the presence of incoming cells and requests bandwidth from a connection admission control (CAC) forming part of the system. The switching system stores a table associating a number of signal sources connected to the ingress with respective predetermined transmission bandwidths and, preferably also, maximum delay times. When arrival of cells from one of the sources at the input port is detected, the DBC sends a request signal for the relevant predetermined bandwidth to the CAC and delays transmission of the cells until at least the predetermined bandwidth is allocated.