Cabletron Systems MICROMMAC- User Manual

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. 

The following sections describe common cable problems and 
recommendations for correcting them. 

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 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).

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.