Abstract: Several rotator switch architectures are provided that enhance performance of a basic rotator switch. The rotator switches having double buffered tandem nodes, multiplexing two or more sources onto each tandem node, partitioning the rotator into two or more parallel space switches, two or more rotator planes multiplexing from/to source and destination nodes to provide data path redundancy, priority queueing on source nodes scheduled locally or globally, or redundancy in the schedulers are shown.

Abstract: A method of scheduling in a switch for transferring data by information units is provided where the scheduling decisions are performed from the destination node point of view, considering the demand of all the source nodes to reach this destination node. This algorithm also allows an improvement in performance, from a traffic point of view, of a rotator switch, since the algorithm is much more fair than the known source based scheduling algorithm in sharing the bandwidth amongst the contenting source nodes for a given destination node. Embodiments of the invention, are extended to support class of service, including minimum bandwidth guarantee. Further embodiments are provided that support age-group to further increase the performance of a rotator switch fabric with respect to traffic.

Abstract: Several rotator switch architectures are provided that enhance performance of a basic rotator switch. The rotator switches having double buffered tandem nodes, multiplexing two or more sources onto each tandem node, partitioning the rotator into two or more parallel space switches, two or more rotator planes multiplexing from/to source and destination nodes to provide data path redundancy, priority queueing on source nodes scheduled locally or globally, or redundancy in the schedulers are shown.

Abstract: Several rotator switch architectures are provided that enhance performance of a basic rotator switch. The rotator switches having double buffered tandem nodes, multiplexing two or more sources onto each tandem node, partitioning the rotator into two or more parallel space switches, two or more rotator planes multiplexing front/to source and destination nodes to provide data path redundancy, priority queueing on source nodes scheduled locally or globally, or redundancy in the schedulers are shown.

Abstract: The invention is a novel method and apparatus for controlling the flow of traffic between a host digital terminal (HDT) and a plurality of optical network units (ONUs). Each ONU is connected to the HDT by optical fiber and to a plurality of subscribers by a respective plurality of subscriber drops (typically pre-existing copper twisted pairs). The bandwidth on the fiber, although large, is usually inferior to the total bandwidth that can be transmitted across the subscriber drops. Therefore, both upstream and downstream traffic may become congested at various “choke points” under certain circumstances of usage. Ordinarily, the data is buffered at the choke points, leading to the installation of large queues within each ONU. This solution is not only expensive, but is inadequate since the required queue size is dependent on the maximum transaction size, which has no hard upper bound.

Abstract: Novel traffic management schemes of a telecommunications network using the concept of virtual links is disclosed. As an example, if a switch connects via a high bandwidth link to an access mux that drives lower bandwidth links. The mux is a potential congestion point in the downstream direction (from high to low bandwidth links) because traffic can arrive at a greater rate over the high bandwidth link than it can exit through the lower bandwidth link. If all of the traffic destined for a particular low bandwidth link can be organized into a unique virtual link. This virtual link can be scheduled at a maximum rate not exceeding the bandwidth of the low bandwidth link, thus preventing the mux from ever becoming a congestion point. Therefore, the amount of mux buffering can be reduced to a very small amount (for jitter absorption). One advantage of this scheme in this example is potentially large cost reductions in the high volume access mux at the lesser expense of a more complex low volume switch.

Abstract: An optical transmission system comprises a transmitter and a receiver linked by an optical path having amplifier stations and incorporating a reflectometer for determining the location of an optical fault in the path. Transmitted signals are tapped from the path at an amplifier station and are processed by a correlation technique to detect the relative timing of reflections from a fault and thereby to determine the location of that fault.