The Catalyst 2900 series XL switches are workgroup Ethernet switches that supply autosensing 10BaseT or 100BaseT connections on all ports. These switches can be deployed as backbone switches aggregating 100BaseT traffic from other switches and hubs or in mixed configurations connecting hubs switches servers and desktops. 10/100 Ports Catalyst 2900 series 10/100 ports are internally switched to all other switch ports and use RJ-45 connectors and Category 5 cabling. They can operate at either 10 or 100 Mbps in full or half duplex. For autonegotiation with other devices the ports are IEEE 802.3u-compliant. When connected to another device a port senses the speed and duplex settings of the attached device and advertises its own capabilities. If the connected device also supports autonegotiation the Catalyst 2900 series port negotiates the best connection and configures itself accordingly. Ports can also be explicitly set to operate in any combination of half duplex full duplex 10 Mbps or 100 Mbps.