We are looking to converge VOIP and Data traffic onto a single wire so that our client's VOIP phones pass data through to the users computer. We are specing out a new Sonicwall NSA appliance to handle routing functions and layer 2 switches to manage VLANS. Not a huge network, medium sized.

What should I know about converging the networks onto a single wire? Obviously I'll want to prioritize voice traffic, is this handled solely in the Sonicwall with QoS configurations or do the layer 2 switches need to be configured differently? Any other pitfalls I should be aware of, or any good resources for learning more?