Traffic shaping system with virtual circuit table time stamps for asynchronous transfer mode networks

摘要

A system for controlling the transmission of cells from a network node over multiple virtual circuit is disclosed. The disclosed system performs traffic shaping for all virtual circuits connected with the network node. The system includes a virtual circuit table with one or more entries. Each virtual circuit table entry corresponds to a virtual circuit established with the network node. Each virtual circuit table further includes one or more Cell Rate Accumulator fields and a Time Stamp field. The system includes a schedule table having one or more entries. Each schedule table entry further includes one or more Cell Rate Accumulator fields and corresponding predetermined value fields. A schedule table loading process determines a virtual circuit on which a packet is to be transmitted, and then calculates a time elapsed since a last previous write of a virtual circuit table entry corresponding with that virtual circuit. The schedule table loading process then adds the time elapsed to the value of the Cell Rate Accumulator fields in that virtual circuit table entry, and stores the result of the addition into the corresponding Cell Rate Accumulator fields of the schedule table entry. The system further includes a process for periodically incrementing the Cell Rate Accumulator fields in the schedule table entry. A scanning process periodically increments the Cell Rate Accumulator fields. A transmitting process transmits a cell on the virtual circuit when the value of the Cell Rate Accumulator fields is greater than or equal to the corresponding predetermined values.