Cabletron Systems EMC39-12 Network Card User Manual


 
EMC39-12 User’s Guide Page A-1
APPENDIX A
CABLE REQUIREMENTS
This appendix provides cable requirements for each of the EMC39-12
ports.
A.1 10BASE-T TWISTED PAIR REQUIREMENTS
When you connect a 10BASE-T twisted pair segment to the EMC39-12,
the device at the other end of the twisted pair segment must meet IEEE
802.3 10BASE-T specifications. Your 10BASE-T twisted pair segment
must meet the following requirements.
Segment Length
The IEEE 802.3 10BASE-T standard requires that 10BASE-T devices
must be able to transmit from 0 to at least 100 meters (328 feet) per
segment of 24-gauge unshielded twisted pair (UTP) cable.
Insertion Loss
The maximum insertion loss allowed for a 10BASE-T segment is 11.5 db
at all frequencies between 5.0 and 10.0 MHz. This includes the
attenuation of the cable, connectors, and patch panel.
Impedance
10BASE-T specifies cable impedance between 85 and 110 ohms.
A.2 SINGLE MODE FIBER OPTIC NETWORK
When connecting a single mode fiber optic link segment to a hub, ensure
the network meets the following requirements:
Cable Type
Fiber optic link segments should consist of 8/125 to 12/125 µm single
mode fiber optic cabling. You can also use 62.5/125 µm multimode cable
however, multimode cable allows for greater optical loss, and limits the
possible distance to 2 km.
emc39bk Page 1 Monday, February 12, 1996 4:21 PM