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Re: A question about priorities





On Tue, 8 Aug 2000, Nikhil Bansal wrote:

> 
> Thanks for the suggestions, I have one more doubt which is troubling me.
> 
> It seems that traffic control comes into play only when traffic is to be
> dequeued to be sent to the output interface. 

true for the egress queueing. There is also ingress policing which happens
on the input.

> Does it also influence how IP layer hands down the  data to the lower layers?
> 

I think this would be the case when the NET_XMIT_* codes start to be used
correctly by the upper layers .... For now the answer is no.

> For example, if I have two UDP sockets one set at a higher priority using
> setsockopt than the other. Then though the packets for the higher priority
> connection are drained first at the interface, if the IP layer hands
> equal amount of data from the socket buffers to the layers below (which it will
> if Traffic control does not affect how sockets are drained), the observed
> throughput for the both the connectons in the long run will be the same,
> (since IP hands equal amount of data from both the connections.)
> 

If you are doing this correctly, then the effect you are describing is
what you should see. 

cheers,
jamal