7Connect to the Switch Ports
This section describes how to connect to the fixed switch ports and to the 10-Gigabit Ethernet module slots.
Connect to 10/100/1000 Ports
The 10/100/1000 Ethernet ports use standard RJ-45 connectors with Ethernet pinouts. The maximum cable length is 328 feet (100 meters). The 100BASE-TX and 1000BASE-T traffic requires Category 5, Category 5e, or Category 6 UTP cable. The 10BASE-T traffic can use Category 3 or Category 4 cable.
The autonegotiation feature is enabled by default on the switch. At this setting, the switch ports configure themselves to operate at the speed of attached devices. If the attached device does not support autonegotiation, you can explicitly set the switch port speed and the duplex parameters. To maximize performance, either let the ports autonegotiate both speed and duplex, or set the port speed and duplex parameters on both ends of the connection.
For simplified cabling, the automatic medium-dependent interface crossover (auto-MDIX) feature is enabled by default on the switch. With auto-MDIX enabled, the switch detects the required cable type for copper Ethernet connections and configures the interface accordingly. Therefore, you can use either a crossover or a straight-through cable for connections to a switch 10/100/1000 Ethernet port, regardless of the type of device on the other end of the connection.
See the switch software configuration guide or the switch command reference on Cisco.com for more information about enabling or disabling autonegotiation and auto-MDIX.
Connect to 10/100/1000 PoE Ports
The 10/100/1000 PoE ports have the same default settings and cabling requirements that are described in the previous section.
The PoE ports provide PoE support for devices compliant with IEEE 802.3af and also provide Cisco pre-standard PoE support for Cisco IP Phones and Cisco Aironet Access Points.
Each port can deliver up to 15.4 W of PoE. With the 1150-W power supply module, the Catalyst 3750E-48PS switch can deliver 15.4 W on all 48 ports. With the 750-W power supply module, the switches can deliver 15.4 W of PoE on any 24 of the 48 ports, or any combination of the ports can deliver an average of 7.7 W of PoE at the same time, up to a maximum switch power output of 370 W. On a per-port basis, you can control whether or not a PoE port automatically provides power when an IP phone or an access point is connected.
See the hardware installation guide on Cisco.com for more information about the switch power supply options.
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