Shielded Twisted Pair (STP)
Table
IBM | Operational |
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Impedance |
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Type | Frequency | 1000 m | (1000 ft) | ||
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1 & 2 | 4 MHz | ≤ 150Ω ±15% | ≤ 22 dB | (≤ 6.7 dB) | |
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| 16 MHz | ≤ 150Ω ±15% | ≤ 45 dB | (≤ 13.7 dB) | |
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6 & 9 | 4 MHz | ≤ 150Ω ±15% | ≤ 33 dB | (≤ 10.0 dB) | |
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| 16 MHz | ≤ 150Ω ±15% | ≤ 66 dB | (≤ 20.0 dB) | |
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IBM Type 6 consists of two STP of 26 AWG stranded wire for data. Because of its high attenuation, Type 6 is used only in patch panels or to connect devices to/from wall jacks. Attenuation for Type 6 cable is 3/2 x Type 1 cable (attenuation for 66 m of Type 6 = attenuation for 100 m of Type 1).
IBM Type 9 is similar to Type 1, but uses 26 AWG solid wire. Like Type 6, because of its high attenuation, Type 9 is used only in patch panels or to connect devices to/from wall jacks. Attenuation for Type 9 cable is 3/2 x Type 1 cable (66 m of Type 9 = 100 m of Type 1).
NOTE |
IBM Types 6 & 9 are to be used only for lobe connections from station to wall jack and patch panels.
B.2.2 STP Lobe Lengths
The maximum lobe length attainable under ideal conditions, is shown in Table
B.2.3 Mixed STP Cable Types
If cable types are to be mixed in the LAN, compensations must be made for the different cable attenuations. For example, Type 6 & 9 cables can be run for only 2/3 the distance of Type 1: 100 meters of Type 1 ≈ 66 meters of Types 6 or 9)
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