NETWORK CONNECTIONS
Page 3 - 9
Table 3-4. Maximum Allowable Attenuation
3.6
IMPEDANCE
The characteristic impedance for UTP cable is 100 ohms
±
15%. For
STP cable, the characteristic impedance is 150 ohms
±
10%.
3.7
CROSSTALK
Is caused by signal coupling between the different cable pairs
contained within a multi-pair cable bundle. In shielded pair cables,
the effects of crosstalk are minimized.
3.8
NOISE
Can be caused by either crosstalk or externally induced impulses.
If noise induced errors are suspected, it may be necessary to re-
route cabling away from potential noise sources (motors,
switching equipment, high current equipment), or to ensure that
the electrical wiring in the area is properly wired and grounded.
WARNING:
It is the responsibility of the person who sells the
system of which the adapter will be a part to ensure that the total
system meets allowed limits of conducted and radiated emissions.
Table 2:
Cable Type
at 4 Mbps
at 16 Mbps
STP (IBM Types 1 and 2
22 dB/Km
45 dB/Km
Voice Grade UTP (IBM Type 3)
56 dB/Km
131 dB/Km
STP (IBM Types 6 and 9)
33 dB/Km
66 dB/Km
