Exactly where in the network stack does the TOS field get used?
I'm trying to get a handle on some quality of service issues and am wondering exactly where in the network stack the Type of Service (TOS) field gets used to order packets by priority.
It is my understanding that the driver layer should not have to concern itself with ordering packets. The packets should already have been prioritized and queued before the driver ever sees them. Is this correct, and if so, where in the stack does this happen?
The other side of the coin is what happens from user applications perspective. How does an application go about marking a particular message with a different priority?