This R&D guide has a lot of examples that you can look at.
So as an example, in a campus environment, we may have what's called conditionally trusted endpoints.
So as an example, a switch would trust the markings that it receives on a port when it sees a phone
through CDP.
Phones are trusted, but PCs are not.
So you'll only trust the markings that you receive when you see a phone connected to the switch port.
So with regards to trust, again, the switch will trust the marking from a phone, but not the marking
from a PC.
So the trust boundary ends at the phone.
The switch will say, I see that you're a phone, so I'll trust your costs.
But a PC costs will not be trusted.
So if a phone marks its traffic with a costs of five for the voice and signaling set to three, that
will be accepted by the switch and it may change those values to a DHCP of 46 and a DHCP of 24.
If a PC sets its costs to five, the phone will automatically reset it to zero and the switch will also
not trust the traffic received by PC.
The Ace R&D guide covers many switch models and many options with regards to trusting certain traffic
types, but not trusting other traffic types.
So as an example here, the switch is trusting the cost value that it receives from a phone.
It uses what are called class maps.
A class map is a way to create groups or classes of traffic.
So in this example, the order was VoIP.
RTP Trust is matching traffic with a DHCP of 46.
That's voice traffic.
The VoIP control trust class is matching DSPs of 24 and 26 now based on those values.
Something can be done with the traffic and in this example, various queuing options are set.
So traffic is prioritized on queues on the switch based on the traffic type that's received.
There are different ways to queue traffic on a switch.
The hardware of switches will dictate how you can queue the traffic, so the number of queues supported
as an example is dependent on hardware.
But essentially the idea is that you can try some traffic types over other traffic types by using a
queue in the same way that first class passengers are priced over economy class passengers.