So the phone once again is sending a layer to marking to the switch using edited at one Q.
The markings in binary are in the range 0 0 0.
All the way to triple 1.
So in binary it looks like this in decimal they'll have values like this and I'll add five here because
that's one used by voice.
So an editor at 1 q header has a field called a priority field for so called cos it's three bits and
size values on this range on the same way when you get to a traffic light and it's red you stop or when
it's green you go.
These markings in of themselves don't mean anything.
It's the interpretation of the marking that counts.
We've all agreed that a red light means stop and a green light means go in the same way the convention
is that voice is marked with a cost value of five.
That's true in Cisco environments.
If you have phones from other vendors they may use a cost of six.
So you need to ensure that your phones and your switches and your routers are configured to agree.
What do these values mean.
So the idea with marketing is we marking packets to indicate it to another device how important that
data is.
So when the packets are sent from Sichuan to switch to as an example switch to can read the packets
and see that they're marked with a cost of five and then prioritize them accordingly.
So prioritize tries them as important voice traffic.
Now one of the problems with editor the one key layer to markings is it requires editing at one Q trunk
puts a link such as this between a switch and a router maybe using a rod at port on a switch which means
that edit to the one Q trucking is not used.
If you send traffic across a serial link as an example or when edited to add one Q tagging is not used.
You may as an example be using BPP or HDL see on a serial link.
So layer two markings such as editor 1 q aren't.
End to end and therefore you may want to use a layer 3 marking.