Until recently, we haven't really found a need to subnet or otherwise segment our small office network. We have Catalyst 3560 switches and a CAT 6 infrastructure, but aren't really utilizing it to the fullest. Now that we are wanting to install a VoIP solution, the vendor made it sound imperative that we segment the network with VLANS using QoS to prioritize the voice, understandably.
We have a Juniper SSG-140, which is a seemingly complex and capable router that is now only acting as our firewall and gateway.
We have two Cisco 3560G as our main data switches, an empty 3560 designated for our office phones, and a 24 port 3560 dedicated to the shop phones, all PoE.
Concerns:
1)Connecting/trunking considerations on the switches. We made the mistake of not getting the switches that can be trunked together in the rear, so have been using one patch cable between the two main data switches. We plan to connect the shop switch to the phone switch in the computer room over fiber. How should the rest of the switches be connected together, and how should these ports be programmed?
2)VLAN segmentation for voice prioritization. We don't really see the need to completely isolate the phone network from the data network, as the phones have ports in the back for laptop users, etc. If this isolation is a requirement of VLANS, that is fine. I have no experience with VLANS, but little experience with the Cisco IOS.
3)I read in some other answers that the core switch needs to be converted into the gateway. Is this necessarily true, or should we use the Juniper router as the gateway as we have been, and integrate the voice VLAN into one of its interfaces.
4) DHCP and other concerns. Defining IP ranges on the server.
I can admit I'm very new to the advanced networking/Cisco world, but would like to possibly try and tackle the configuration with some assistance. Keeping it simple would be great to start. I greatly appreciate any help.
