Garbage in; garbage out.
But seriously…
It’s a question that cannot be answered. Voice over IP only defines a transmission system down to layer 3 of the OSI model. Layer 2 can be anything. It could be Ethernet, PPP or Token Ring. These layer 2 (link layer) protocols in turn have different options for layer 1 (physical layer), and this effects the cabling requirements.
For example, IF you use Ethernet (and you don’t have to), you could use CAT 5 cables or coaxial. As long as they both meet Ethernet’s requirements, they’ll work for VoIP.
So, you see, your question cannot be answered.
just remember to stick with green cables, and learn how to spell WIRING ;-)…
…and remember that us Europeans have a different sense of humour to you Americans.