The 4000 series of managed switches offers Gigabit capability, fiber options and a variety of port-count combinations. The series operates on the same firmware platform as the previously released 3000 series for Fast Ethernet. The switches have up to four fiberoptic ports for establishing star and tree topologies, as well as connecting subnetworks to higher-level networks. They combine IEEE functions and extended ring redundancy for switchover times of 15 ms, with several hundred switches in the ring. The network manager can customize access to the switch’s Web page by user role to address job-function or security-level requirements.