Abstract:
A method and apparatus of reorganizing cells received over data communication lines at a receive node is provided. The cells have an initial order identified by monotonically increasing sequence identifiers. The receive node has buffers associated with respective ones of the communication lines. Each of the buffers has an output position. A cell having a smallest sequence identifier is detected from one or more cells at the output positions of the buffers. It is determined if the smallest sequence identifier is sequentially consecutive to a specified sequence identifier. If the smallest sequence identifier is sequentially consecutive to the specified sequence identifier, the cell having the smallest sequence identifier is dequeued from an output position of one of the buffers and the specified sequence identifier is redefined as the smallest sequence identifier.
Abstract:
A method of minimizing SID difference of simultaneously transmitted cells in two or more data communication lines is provided. A data transmission speed of each of the two or more data communication lines is identified. A fullness threshold of at least one buffer of two or more buffers in a transmit node is configured in relation to a size of a data cell for transmission. The two or more buffers correspond to respective ones of the two or more data communication lines. The at least one buffer communicates with a given one of the two or more data communication lines having a data transmission speed slower than another of the two or more data communication lines. One or more data cells for transmission are assigned to the two or more buffers of the two or more data communication lines at the transmit node. The one or more data cells are transmitted from the transmit node to a receive node in accordance with the data transmission speeds of the two or more data communication lines. The fullness threshold of the at least one buffer controls assignment of data cells to the at least one buffer during data cell transmission on the given data communication line and minimizes SID difference of simultaneously transmitted cells in the two or more data communication lines.
Abstract:
Methods and apparatus for synchronizing a first clock of a transmit node and a second clock of a receive node in a packet network are provided. Receive time stamps are generated for transferred packets at a receive node in-accordance with the second clock. Propagation delay variation is filtered from receive time stamp intervals through a filter in accordance with a frequency of the second clock. The filtered receive time stamp intervals and transmit time stamp intervals of the transferred packets are input into a phase locked loop to generate a new frequency for the second clock. The filter and the second clock are updated in accordance with the new frequency for synchronization with the first clock of the transfer node.
Abstract:
In one embodiment, an apparatus for coordinating merging of packets for one or more virtual circuits (VGs). Each packet of a VC comprising a sequence of cells terminates with an end of packet (EOP) cell. The apparatus comprises one or more buffers, a buffer controller, and a merge processor. Each buffer is configured to receive cells of an associated VC and a threshold value based on traffic of the VC. When a number of cells of a packet in a buffer exceeds the corresponding dynamic threshold value, a corresponding flag of the buffer is set. The buffer controller is configured to drop all cells of the current packet in response to a set flag of a corresponding buffer. The merge processor services each buffer in accordance with a scheduling method to transfer one or more packets from each buffer to an output packet stream.
Abstract:
A multi-stage scheduler that provides improved bandwidth utilization in the presence of processor intensive traffic is disclosed. Incoming traffic is separated into multiple traffic flows. Data blocks of the traffic flows are scheduled for access to a processor resource using a first scheduling algorithm, and processed by the processor resource as scheduled by the first scheduling algorithm. The processed data blocks of the traffic flows are scheduled for access to a bandwidth resource using a second scheduling algorithm, and provided to the bandwidth resource as scheduled by the second scheduling algorithm. The multi-stage scheduler in an illustrative embodiment may be implemented in a network processor integrated circuit or other processing device of a communication system.
Abstract:
Methods and communication networks having a plurality of connection-oriented switches in which administrative weights are assigned based on link call blocking probabilities. Three assignment schemes include, first, a solution that can be built in the switch software of sufficiently similar switches to enable the switches to determine administrative weights for their links. The second and third schemes employ administrative weight management stations. The second scheme uses an administrative weight management station that operates to enhance total network revenue or throughput in a communication network in which all of the switches implement a certain type of accounting management information databases (MIB). The third scheme uses an administrative weight management station that computes administrative weights for switches that do not have the capability for the second scheme, but which employ appropriate MIBs.
Abstract:
An integrated circuit device for use in a line card of a network node of a digital networking system is provided. The integrated circuit device is capable of intercepting one or more control messages from at least one CPE device. The one or more control messages correspond to at least an operational status of at least one TE device associated with the at least one CPE device. The integrated circuit device is also capable of transmitting one or more rate control messages to a network processor of the network node to adapt bandwidth utilization and provide adapted data traffic flow to at least one CPE device in relation to the operational status of the at least one TE device.
Abstract:
Methods and apparatus for synchronizing a first clock of a transmit node and a second clock of a receive node in a packet network are provided. Receive time stamps are generated for transferred packets at a receive node in-accordance with the second clock. Propagation delay variation is filtered from receive time stamp intervals through a filter in accordance with a frequency of the second clock. The filtered receive time stamp intervals and transmit time stamp intervals of the transferred packets are input into a phase locked loop to generate a new frequency for the second clock. The filter and the second clock are updated in accordance with the new frequency for synchronization with the first clock of the transfer node.
Abstract:
A method of minimizing SID difference of simultaneously transmitted cells in two or more data communication lines is provided. A data transmission speed of each of the two or more data communication lines is identified. A fullness threshold of at least one buffer of two or more buffers in a transmit node is configured in relation to a size of a data cell for transmission. The two or more buffers correspond to respective ones of the two or more data communication lines. The at least one buffer communicates with a given one of the two or more data communication lines having a data transmission speed slower than another of the two or more data communication lines. One or more data cells for transmission are assigned to the two or more buffers of the two or more data communication lines at the transmit node. The one or more data cells are transmitted from the transmit node to a receive node in accordance with the data transmission speeds of the two or more data communication lines. The fullness threshold of the at least one buffer controls assignment of data cells to the at least one buffer during data cell transmission on the given data communication line and minimizes SID difference of simultaneously transmitted cells in the two or more data communication lines.
Abstract:
A method and apparatus of reorganizing cells received over data communication lines at a receive node is provided. The cells have an initial order identified by monotonically increasing sequence identifiers. The receive node has buffers associated with respective ones of the communication lines. Each of the buffers has an output position. A cell having a smallest sequence identifier is detected from one or more cells at the output positions of the buffers. It is determined if the smallest sequence identifier is sequentially consecutive to a specified sequence identifier. If the smallest sequence identifier is sequentially consecutive to the specified sequence identifier, the cell having the smallest sequence identifier is dequeued from an output position of one of the buffers and the specified sequence identifier is redefined as the smallest sequence identifier.