Cabling and Technology Information
Twisted-Pair Cable/Connector Pin-Outs
Twisted-Pair Cable/Connector Pin-Outs
Auto-MDIX Feature: The 10/100/1000-T ports support the IEEE 802.3ab standard, which includes the “Auto MDI/MDI-X” feature. In the default configuration, “Auto”, the ports on the Switch 3500 all automatically detect the type of port on the connected device and operate as either an MDI or MDI- X port, whichever is appropriate. So for any connection, a straight-through twisted-pair cable can be used -- you no longer have to use crossover cables, although crossover cables can also be used for any of the connections.
If you connect a 3500 switch twisted-pair port to another switch or hub, which typically have MDI-X ports, the 3500 port automatically operates as an MDI port. If you connect it to an end node, such as a server or PC, which typically have MDI ports, the 3500 switch port operates as an MDI-X port. In all cases, you can use standard straight-through cables or crossover cables.
If you happen to use a correctly wired crossover cable, though, the switch will still be able to automatically detect the MDI/MDI-X operation and link correctly to the connected device.
Other Wiring Rules:■All twisted-pair wires used for 10 Mbps, and 100 Mbps operation must be twisted through the entire length of the cable. The wiring sequence must conform to EIA/TIA 568-B (not USOC). See “Pin Assignments” later in this appendix for a listing of the signals used on each pin.
■For 1000Base-T connections, all four pairs of wires in the cable must be available for data transmission. See “Note on 1000BASE-T Cable Require- ments” on page B-1for more information on 1000Base-T cabling.
■For 10 Mbps connections to the ports, you can use Category 3, 4, or 5 unshielded twisted-pair cable, as supported by the IEEE 802.3 Type 10Base-T standard.
■For 100 Mbps connections to the ports, use 100-ohm Category 5 UTP or STP cable only, as supported by the IEEE 802.3u Type 100Base-TX stan- dard.
■For 1000 Mbps connections, 100-ohm Category 5e or better cabling is recommended.
