Cabletron Systems MicroMMAC 24T MICROMMAC- - Manual (Page 27)

REQUIREMENTS/SPECIFICATIONS
2-8
Fiber Optic Budget
The fiber optic delay budget, which determines the fiber optic cable’s
maximum length, should be calculated and taken into consideration in the
network design stage. Fiber optic delay budget is determined by summing
the optical signal loss due to fiber optic cable attenuation, in-line splices,
and fiber optic connectors.
2.2 CABLE RECOMMENDATIONS/TROUBLESHOOTING
The following sections describe common cable problems and
recommendations for correcting them.
Crosstalk
Crosstalk is interference caused by signal coupling between different cable
pairs contained within a multi-pair cable bundle. Multi-pair cables should
not be used for UTP lobe cabling. UTP lobe cabling should be dedicated
to carrying Token Ring traffic. Avoid mixing Token Ring signals with other
applications (voice, etc.) within the same cable.
Noise
Noise can be caused by crosstalk or externally imposed impulses. If
noise-induced errors are suspected, ensure that the electrical wiring in the
area is properly wired and grounded and/or try re-routing cabling away
from potential noise sources (motors, switching equipment, fluorescent
lighting, high amperage equipment).
Temperature
The attenuation of PVC-insulated cable varies significantly with
temperature. Check the cable manufacturer’s specifications. Plenum-rated
cables are strongly recommended in areas where temperatures exceed
40˚C. Under such conditions, plenum-rated cables ensure that cable
attenuation remains within specifications.