Hi Chris,
There are different ways to set up hosted VoIP. You can connect the computer and phone to the same Ethernet jack by running through the computer. You then need power for the phone. So, you have to buy $30 to $40 power converters for the phones and you have extra cables, etc. It really isn't the best way to go.
This is why I ALWAYS say, ALWAYS, when you buy a switch, buy a PoE switch. This doesn't cost that much extra, and the phones which connect via the switch automatically get power via the switch. So, you aren't dependent on the extra hardware at the computer. And, if you have a separate Ethernet jack (see Sandeep's eight per office -- most won't need that much), you don't become dependent on the computer.
So, now they connect to the switch. Set up a VLAN, so your VoIP is on a separate network. A good switch will have QOS. You need something to control the amount of bandwidth since it is being shared. You don't really care if your receptionist is having a slow Facebook connection, but you want your packets consistent for your phones. So, it is like a governor to make sure you have enough speed.
Remember, with VoIP, upload speed is just as important as download speed for good quality. With a good hosting company, they will check packets throughfare. They won't tolerate dropping more than a few packets.
Our company didn't like the quality so they said, screw TWC. We will give you free DSL. Got a 1 Mbs dedicated DSL. Plus if TWC goes down, we can switch.
Bottom line. If serious about VoIP, get a quality managed PoE switch with vLAN capabilities.
