6 Replies Latest reply: Jul 8, 2011 4:07 AM by DEEPAK ARORA RSS

    Shared Round Robin Question

    Michael Law

      I'm curious....as to why we need to classify and schedule frames being received on the switch on the ingress port. For every other topic regarding QoS, the issue always settles with the fact that congestion occurs when the cumulative input exceeds the available output. Queues fill and "congestion" has occurred. How can an ingress port be congestion?


      I understand that there is a scheduler that "moves" the frame from the ingress buffer to the switching fabric. Priority queuing allows those latency sensitive frames to move through quicker. But, if all the traffic coming down the wire is serial, and the ingress buffer is designed to handle that load, again...where is the congestion.


      My thoughts were that if congestion were to occur, it would happen after the frame is passed through the switching fabric to the egress buffer.