Abstract: A source selection system for a communication switch for selecting a primary datasource from a plurality of datasources is provided. The system includes a validation module associated with the plurality of datasources adapted to monitor each datasource of the plurality of datasources for transmission errors in output originating from each datasource and adapted to provide information relating to the transmission errors. The system also includes a source selector associated with the validation module and the plurality of datasources, the source selector adapted to select an output datasource from the plurality of datasources. The system further includes an assessment module associated with the validation module adapted to identify the primary datasource from the plurality of datasources utilizing the information provided by the validation module and adapted to cause the source selector to select the output datasource associated with the primary datasource.

Abstract: Communication traffic policing apparatus and methods are disclosed. Communication traffic restrictions for each communication link in a group of communication links are enforced by allowing transfer of communication traffic associated with respective communication links of the group at transfer rates up to respective per-link transfer rates. In a group enforcement stage, transfer of additional communication traffic associated with a communication link of the group, above the per-link transfer rate for the communication link, is allowed where a combined transfer rate of communication traffic associated with another communication link of the group and the additional communication traffic would not exceed the per-link transfer rate for the other communication link. Thus, one or more individual communication links of a group may be allowed to effectively exceed their per-link transfer rates if one or more other communication links of the group have sufficient spare capacity.

Abstract: A communication switch is provided for customer premise equipment. The switch comprises a communication module which processes communications between elements in the communication switch, a shelf module which has an interface point for the customer premise equipment to the communication module, and a chassis. The shelf module comprises an I/O card providing the interface point, a line processing card, a midplane providing a connections to the I/O card and the line processing card and connections for the midplane to the communication module. The shelf module communicates with the communication module via a communication link. The link may be connected and disconnected without disrupting operation of other shelf modules connected to said communication module.

Abstract: Apparatus and method for implementing virtual path aggregation (VPA) of underlying virtual connections at a switching node of a connection based communications network. A multi-service traffic shaping module (MTSM) at the switch implements algorithms to aggregate the VC and VP connections onto the aggregate VP by representing an aggregate VP as a plurality of circular linked lists or loops and assigning each VC connection to a link or element in the circular linked lists according to traffic descriptors. Weighting factors are used as between loops to dynamically select the next loop to service. Once this loop is chosen, the next VC to be serviced is identified by examining the circular linked list structure.

Abstract: Apparatus for transmitting a data stream between cards connected by a midplane breaks the data stream into a plurality of channels. The apparatus comprises a serializer for each channel. Serialized data is transmitted across the midplane to a deserializer at the destination. Sequential cells are sent in different channels. Cell ordering is preserved by staggering the start of cell transmission in the channels. The invention permits data to be transmitted across a mid plane using a reduced number of data lines. The data stream on each card may be carried in a wide bus at a relatively low clock rate. Apparatus according to the invention may be used to transmit an OC-192 data stream across a pin-limited interface.

Abstract: A source selection system for a communication switch for selecting a primary datasource from a plurality of datasources is provided. The system includes a validation module associated with the plurality of datasources adapted to monitor each datasource of the plurality of datasources for transmission errors in output originating from each datasource and adapted to provide information relating to the transmission errors. The system also includes a source selector associated with the validation module and the plurality of datasources, the source selector adapted to select an output datasource from the plurality of datasources. The system further includes an assessment module associated with the validation module adapted to identify the primary datasource from the plurality of datasources utilizing the information provided by the validation module and adapted to cause the source selector to select the output datasource associated with the primary datasource.

Abstract: A communication switch is provided for customer premise equipment. The switch comprises a communication module which processes communications between elements in the communication switch, a shelf module which has an interface point for the customer premise equipment to the communication module, and a chassis. The shelf module comprises an I/O card providing the interface point, a line processing card, a midplane providing a connections to the I/O card and the line processing card and connections for the midplane to the communication module. The shelf module communicates with the communication module via a communication link. The link may be connected and disconnected without disrupting operation of other shelf modules connected to said communication module.