I am upgrading my school's computer network to enable telephony on the network. I have upgraded my three switches to Cisco SG-220-50p to give me PoE and better management. I am implementing VLANs (public, staff, students, voice) to segregate traffic, provide QoS, etc. An IT consultant advised me to purchase these L2 switches and that I would not need a router on my network because I have no need for inter-VLAN connectivity.
That consultant has moved on and I am in the process of configuring the network with the aid of another consultant. This one is telling me that I need a router or L3 switch to allow each of the VLANs to access the gateway. So, I am looking at the Cisco SG300-10.
If it matters to this question I also have a Sonicwall NSA-220.
I am looking for advice on which direction is right.
Thanks in advance