Selecting Appropriate Cable Lengths
2-9
Connection Hardware
The performance of installed cable only meets the specifications listed
when your connection hardware level is greater than or equal to the
level of the installed cable. Connector hardware is specified in
SP-2840:
Commercial Building Telecommunications Cabling Standard
(ANSI/TIA/EIA) and EIA/TIA TSB-40.
3Com Trunk Cable
Recommendations
CoreBuilder 5000 Token Ring products have either copper or fiber trunk
(Ring-In/Ring-Out) ports. This section lists trunk cabling requirements
for:
■
■
Copper Trunk Cables
Connect copper trunk ports using Unshielded Twisted Pair (UTP) 3, 4, or
5 and Shielded Twisted Pair (STP). The distances are the same as the
active lobe port distances. (Refer to
for trunk cable lengths.)
However, for the highest integrity, use only STP and UTP 5 for
connecting trunks.
When configuring ports 17 and 18 as trunks, cable adapter 6200ADT-RI
must be connected on port #18.
Fiber Trunk Cables
Ensure that fiber-optic trunk cables are:
■
Multimode
■
Grade-index optical fiber waveguide with nominal 62.5/125
µ
M
core/cladding diameter
Table 2-8
120 ohm Cable Specifications
Characteristics
4 Mbps
16 Mbps
Impedance
120 ohms
120 ohms
Attenuation (dB/100 m)
3.5 dB
6.2 dB
NEXT Attenuation, max
46 dB
38 dB