HP ProCurve 2650

B-5
Switch Ports and Network Cables
Twisted-Pair Cable/Connector Pin-Outs
Switch Ports and Network
Cables
Twisted-Pair Cable/Connector Pin-Outs
The HP Auto-MDIX Feature: In the default configuration, “Auto”, the
fixed 10/100Base-TX ports on the Switch 2650 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. (The 10/100/
1000-T ports support the IEEE 802.3ab standard, which includes the “Auto
MDI/MDI-X” feature, which operates the same way.)
If you connect a Switch 2650 twisted-pair port to another switch or hub, which
typically have MDI-X ports, the Switch 2650 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 Switch 2650 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.
Note Using Fixed Configurations. If the port configuration is changed to any of
the fixed configurations though, for example 100 Mbps/full duplex, the port
operates as MDI-X only and the correct cable type must be used: for connec-
tions to MDI ports, such as end nodes, use a “straight-through” cable; for
connections to MDI-X ports, such as on hubs and other switches, use a
“crossover” cable.
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 “Twisted-Pair Cable 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. Please see “Note on 1000Base-T Cable
Requirements” on page B-1 for more information on 1000Base-T
cabling.