HP (Hewlett-Packard) HP J3177A Switch User Manual


 
A-1
Cables and Connectors
A
Cables and Connectors
This appendix lists cables that have been tested and verified for use with the
HP Switch 208/224. It also includes minimum pin-out information so, if you
wish to use an unlisted cable, you can verify that the cables used in your
installation are correctly wired. Note that each pin-out does not necessarily
match the pin-out for the corresponding HP cable, but cables manufactured
to follow the minimum pin-out will function correctly.
Note Incorrectly wired cabling is the most common cause of problems for LAN
communications. HP recommends that you work with a qualified LAN cable
installer for assistance with your cabling requirements.
Twisted-Pair Cable/Connector Pin-Outs
The RJ-45 ports (10 Mbit/s and 100 Mbit/s, both fixed and transceiver) on the
Switch 208/224 are wired as MDI-X ports. The type of twisted-pair cable you
connect to these ports (either “straight through” or “crossover”) depends on
the type of device at the other end of the cable.
The basic rule is, when connecting same-type ports together (for example
MDI-X-to-MDI-X), use crossover cable; when connecting opposite-type ports
together (for example MDI-X-to-MDI), use straight-through cable.
These additional rules apply:
All twisted-pair wires used must be twisted through the entire length of
the cable. The wiring sequence must conform to AT&T 258A (not USOC).
See “Twisted-Pair Cable Pin Assignments” later in this appendix for a
listing of the signals used on each pin.
For connections to the 10 Mbit/s 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 connections to the 100 Mbit/s ports, use Category 5 only, as supported
by the IEEE 802.3u Type 100Base-TX standard.
YUMABOOK.BK : a_cables.fm5 Page 1 Thursday, February 20, 1997 9:35 AM