Twisted-Pair Cable/Connector Pin-Outs - HP J4902A Installation And Getting Started Manual

Twisted-Pair Cable/Connector Pin-Outs

The IEEE 802.3ab "Auto MDI/MDI-X" Feature: The 10/100/1000Base-T
ports on the Switch 6108 all have the "Auto MDI/MDI-X" feature that is part of
the IEEE 802.3ab standard. They automatically detect the type of port on any
device connected to the Switch 6108 and then operate as either an MDI or
MDI-X port, whichever is appropriate. If you connect a Switch 6108 twisted-
pair port to another switch or hub, which typically have MDI-X ports, the
Switch 6108 ports operates as an MDI port and connects correctly. If you
connect an end node, such as a server or PC which typically have MDI ports,
to the Switch 6108, the switch port operates as an MDI-X port and connects
correctly.
So, for any connection, a "straight-through" twisted-pair cable can be used —
you no longer have to use "crossover" cables. If you do happen to use a
correctly wired crossover cable, though, the switch will still be able to
automatically detect the MDI/MDI-X operation of the connected device and
will link correctly.
N o t e
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:
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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.
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.
Switch Ports and Network Cables
Twisted-Pair Cable/Connector Pin-Outs
B-5