Port congestion notification in a switch
    4.
    发明申请
    Port congestion notification in a switch 审中-公开
    交换机中的端口拥塞通知

    公开(公告)号:US20050088969A1

    公开(公告)日:2005-04-28

    申请号:US10873329

    申请日:2004-06-21

    摘要: A congestion notification mechanism provides a congestion status for all destinations in a switch at each ingress port. Data is stored in a memory subsystem queue associated with the destination port at the ingress side of the crossbar. A cell credit manager tracks the amount of data in this memory subsystem for each destination. If the count for any destination exceeds a threshold, the credit manager sends an XOFF signal to the XOFF masks. A lookup table in the XOFF masks maintains the status for every switch destination based on the XOFF signals. An XON history register receives the XOFF signals to allow queuing procedures that do not allow a status change to XON during certain states. Flow control signals directly from the memory subsystem are allowed to flow to each XOFF mask, where they are combined with the lookup table status to provide a congestion status for every destination.

    摘要翻译: 拥塞通知机制为每个入口处的交换机中的所有目的地提供拥塞状态。 数据存储在与交叉开关入口侧的目标端口相关联的存储器子系统队列中。 小区信用管理器跟踪每个目的地的该存储器子系统中的数据量。 如果任何目的地的计数超过阈值,则信用管理器向XOFF掩码发送XOFF信号。 XOFF掩码中的查找表基于XOFF信号维护每个交换机目的地的状态。 XON历史寄存器接收XOFF信号,以允许在某些状态下不允许状态更改为XON的排队过程。 来自存储器子系统的流量控制信号被允许流向每个XOFF掩码,其中它们与查找表状态组合以提供每个目的地的拥塞状态。