I am trying to understand the QOS toolsets and applying them in different scenarios.
Scenario 1: There are multiple inputs into a switch for eg: 8 x 100Mb ports and only 1 x 1Gb uplink port out of that switch
1. Is there be any benefit in using QOS? The reason I am confused is because there is still 200Mb of unused bandwidth on the uplink there is no congestion and from reading other posts it says that QOS is only applied if there is congestion.
2. If there is no QOS than can it be that if 1 of the 100Mb input interfaces has a constant rate of traffic than would other traffic from the other 100Mb ports be subject to wait times or delay of any sort on the 1Gb uplink. What tool if any would be helpful in such a scenario?
Scenario 2: There are multiple inputs into a switch for eg: 12 x 100Mb ports and only 1 x 1Gb uplink port ouf of the switch
1. In this case I assume we would have to use QOS however which tool in the QOS toolset would be used. I am thinking only shaping. Is that correct? Would shaping result in any drop packets and would there be any other considersations?
2. is there a difference between shaping and congestion avoidance like WRED etc and queuing and how would congestion avoidance and queuing?
3. Why is it that ports have lesser receive queues and more transmit queues and why is queuing only configured in the transmit direction but not in the receive direction?
4. Shouldn't a packet be placed in a queue as soon as you receive it on the port and also to prioritize it across the backplane?