We're bringing a location over into our corporate environment and they're going to be using Avaya phones. The user workstations will be connected into the phone and the phone will be connected into a Dell switch. The Dell is uplinked to the 3750 on port g4/0/26. I've changed the native vlan on the Dell to 95 and I set the native on the 3750 to 95. The phones come over VLAN 10. Everything works as expected to this point.
I now need to set up QoS on the 3750. Can I just create class-maps that match the subnet and ports to assign EF for the phone subnet, or do I need to do something with L2 CoS also? This will actually be the first time that I've set up a L2 QoS config.
I assume you're running at least 100MB so I doubt you'll need to prioritize. If you're looking something quick and dirty, you can use AutoQoS.
mls qos trust means that the port will trust the markings that come through on the packet. It's useful for when the phone marks the traffic. Here's an example (from a 4500) on setting the priority~
auto qos voip trust
bandwidth percent 33
shape percent 33
service-policy output autoqos-voip-policy
The QoS Campus SRND is excellent and covers LAN QoS and covers everything in depth.