Method of and system for pre-fetching input cells in ATM switch
    1.
    发明授权
    Method of and system for pre-fetching input cells in ATM switch 失效
    ATM交换机中预取输入单元的方法和系统

    公开(公告)号:US5687324A

    公开(公告)日:1997-11-11

    申请号:US555021

    申请日:1995-11-08

    IPC分类号: H04L12/56 G06F13/00

    摘要: An ATM switch with multicast capability uses a feedback mechanism for resolving contentions. A multicast network reads N cells from an input queue, replicates multicast cells and translates their addresses in accordance with an external look-up table. The processed N cells are stored in a temporary buffer until information regarding the number (F) of cells fed back due to contention in the previous switching cycle is available. A rotator positions N-F cells from the temporary buffer on inputs of an output network so as to assign the cells from the temporary buffer a lower priority than a priority of the feed back cells. The output network selects the cells that can be switched to their destinations and transfers them to output ports. The cells that cannot be switched due to contention are fed back to be presented for the output network consideration in the next switching cycle. At the same time, a pointer of the input queue is decremented by a factor depending on the number of feedback cells, and the number of multicast and unicast cells in the current switching cycle.

    摘要翻译: 具有组播功能的ATM交换机使用反馈机制来解决争用。 组播网络从输入队列中读取N个单元,根据外部查找表复制多播单元并翻译其地址。 处理的N个单元被存储在临时缓冲器中,直到有关由于在前一个切换周期中的争用而被反馈的单元的数量(F)的信息可用。 旋转器将来自临时缓冲器的N-F个单元从输出网络的输入端定位,从而将来自临时缓冲器的单元分配给比反馈单元优先级低的优先级。 输出网络选择可以切换到目的地的单元,并将其传输到输出端口。 反馈由于竞争而不能切换的单元被反馈以在下一个切换周期中呈现用于输出网络的考虑。 同时,输入队列的指针根据反馈单元的数量以及当前切换周期中的组播和单播小区的数量而减少。