Fiber links from ERC run to a switch in the main wiring closet in each of 24 buildings (SAC is treated as one unit). Those are connected in turn to smaller, 48-port switches in secondary wiring closets within the building (typically one on each floor). The individual hosts plug into those ports.
The links between the buildings and the links between the main building switches and the smaller switches operate at 1 Gbps, and use optical fiber. Most of the links to the hosts are 100 Mbps, though a few are still 10 Mbps. They use twisted pairs of copper wires.
Note that we have a router inside the firewall on our campus. That router separates our campus LAN into several virtual LANs, primarily for security. For example, the computers in student labs are on one virtual LAN and the administrative computers with sensitive registration information are on another one.
Our networking staff is responsible for everything up to the CSU router. CSU staff is responsible for that router and the connection running from the campus LAN to the backbone network.
