摘要:
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.
摘要:
A method of reducing overhead for datagrams that are transmitted to or received from a serial link that reduces overhead to no more than four bytes. The datagram includes at least a Protocol Data Unit (PDU) field, a Start-of-PDU Header (SPH) field, and a SPH Control (SCH) field. The SPH and SCH fields consist of two bytes. The datagram may additionally include End-of-PDU Header (EPH) and EPH Control (ECH) fields. A method may also involve substitution of flags for subsequent headers that are identical to previous headers.
摘要:
A configurable chassis guidance system and method are described. The system may be practiced as a chassis and/or a module or an element thereof (e.g., a mating guide). The system and method allow reconfiguration of multiple modules of various module widths without the need for removal or reinstallation of module guides mounted on the chassis. As an example, a single-width module may be removed and replaced by a double-width module or quadruple-width module without removing module guides used to engage the single-width module. As another example, a double-width module or quadruple-width module may be removed and replaced by a single-width module without removing module guides used to engage the double-width module or quadruple-width module. The system and method may be practiced so as not to impair compatibility of modules with card edge module guides that engage an edge of a circuit board of a module.
摘要:
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.
摘要:
An egress traffic management system for a data communication system is disclosed. The egress traffic management system makes use of a hierarchical queue ID header paradigm that enables data packets to be directed for egress traffic management to either one of a plurality of assignable queues in a main egress queue module or to one of a plurality of distributed queue modules via a common queue of the main egress queue module. This behavior enables egress traffic management functionality and scale to be varied independently and in a cost-effective manner to meet evolving requirements of a data communications system.
摘要:
Distributed communication traffic control systems and methods are disclosed. An amount of communication traffic received from a traffic management device and stored in a communication traffic queue at a communication device is monitored. Based on the amount of communication traffic stored in the communication traffic queue, a determination is made, at the communication device, as to whether a traffic management action is to be performed. If a traffic management action is to be performed, the traffic management device is controlled to perform the determined traffic management action. The traffic management device may receive an indication of the determined traffic management action from a distributed traffic controller in the communication device, for example, and perform the traffic management action responsive to the indication.
摘要:
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.
摘要:
Embodiments of the invention provide flow control of incoming data packets to data processing resources via a controller that can receive and react to advanced backpressure messages. These advanced backpressure messages are used to rate limit the data packets based one or more of the following factors: traffic class, traffic priority, destination port. The controller can also generate a traffic preference message to an upstream source of the data packets to inform the upstream unit of the most appropriate type of data that should be transmitted downstream at that time, thereby improving the likelihood of the transmitted data being processed in a proper and timely manner by the downstream data processing resources. Embodiments of the invention can improve the performance of a communications system during periods of congestion by ensuring that high-priority traffic has precedence over traffic of lower priority while maximizing utilization of the ingress data path bandwidth.
摘要:
A method for communicating backpressure messaging over a serial encoded link is disclosed. Embodiments of the invention enable advanced backpressure signaling to be retrofitted into legacy systems to achieve performance improvements and support new or enhanced services. Specifically, such signaling enables per-context and per-priority backpressure signaling information to be conveyed by a backpressure message; thereby enabling flow control to be performed in accordance with a priority or context associated with a traffic flow, or flows, carried over the serial link.
摘要:
Embodiments of the invention provide flow control of incoming data packets to data processing resources via a controller that can receive and react to advanced backpressure messages. These advanced backpressure messages are used to rate limit the data packets based one or more of the following factors: traffic class, traffic priority, destination port. The controller can also generate a traffic preference message to an upstream source of the data packets to inform the upstream unit of the most appropriate type of data that should be transmitted downstream at that time, thereby improving the likelihood of the transmitted data being processed in a proper and timely manner by the downstream data processing resources. Embodiments of the invention can improve the performance of a communications system during periods of congestion by ensuring that high-priority traffic has precedence over traffic of lower priority while maximizing utilization of the ingress data path bandwidth.