Catalyst 5000 family switches support both 4- and 16-Mbps Token Ring networks. This fiber Token Ring module (WS-X5031) has 16 Volition VF-45 socket connectors for Token Ring connections. The 16 ports on the fiber Token Ring module support 62.5 micron multimode fixed fiber connections through ST to Volition VF-45 or SC to Volition VF-45 patch cords.The ports on the Catalyst 5000 family fiber Token Ring module allow you to attach the module to a traditional main ring path coming from either a multistation access unit (MSAU) or a controlled access unit (CAU). You can configure any of the 16 ports to connect to the ring in/out ports of a MSAU or CAU. The module has a loopback function that ensures that there is no break in the attached main ring, even if a port is disabled or the switch is powered off. When you attach a cable from the RI port of a MSAU port to one of the two switch ports, you join the primary and backup in a MAU/CAU main ring system. Connecting the other end of the main ring to the other switch port creates redundant paths because the two switch ports are connected to the same segment.