Hi there,
A.1. F.E. in a router with LLQ you get a policer which kicks in when the interface is overloaded and there is more voip traffic than supposed to be. Delaying (=queueing) voice doesn´t make sense either. So drop it, if you try to protect your resources for other traffic. In general VoIP traffic should be limited by call admission control.
A.2. Well that cannot be answered in general. Again what do you try to achieve with the policer? Figure out what you try to protect when dropping traffic with a policer ... and how much of the policed traffic you want to enter your network. In the end this is resource planning in the network.
A.3. ;-)
In a switch you usually have a LOT of bandwidth with respect to a VoIP call so no policing needed. Unless you want to protect yourself from viruses and worms that mimic voip.
Hope this helps
Martin
