If you’ve already got enterprise-class switching infrastructure you likely already have POE, QOS and 1 Gb speed to each network drop. If that is all true, simply specify handsets that will pass 1 Gb to the desktop. VOIP phones have two ethernet connectors - one for link to the network (the “goes-inta”) and the other for connection to the local workstation (the “goes-outa”). Gig phones will pass 1 Gb to the workstation. They’re more expensive but if you want Gb speed, don’t let the phone implementation create bottlenecks at each desktop. A number of suggestions advocating the use of a small, 4 port gig switch at the desktop are cost effective. Not certain but that may have an impact on the ability of QOS since the 4 port switch appears as a single collision-domain to the infrastructure port. Your throughput would likely suffer but, more importantly, the QOS function might be foiled. QOS can prioritize voice over data and POE will power the handset. Something to consider if this scenario is true - if you have to have dial tone during a power outage, you’ll have to equip your switch racks with UPS backups.
Choice of VOIP vendor is not dependent upon the switch infrastructure. I’ve seen plenty of mixed environments that work flawlessly with, say, Cisco VOIP and Avaya/Nortel infrastructure. Good luck....
With the exception of a couple of users, most data requests to the server were ridiculously below 100mb.
Like many, I have wondered what John1111 is running to the site. Fiber? And what is that they need 1gb at each station.