MEDIA SPECIFICATIONS AND REQUIREMENTS
B-2
B.2 SHIELDED TWISTED PAIR (STP)STP cable categories are listed as follows:
•IBM Type 1 consists of two STP lengths of 22 AWG solid wire for
data. There are three versions of Type 1: Indoor, Outdoor, and Plenum.
It is typically used for the longest cable runs within the walls of
buildings.
•IBM Type 2 is similar to Type 1 data cable, but has four additional
UTP lengths of 22 AWG solid wire carried outside of the shield casing.
There are two versions of Type 2: Plenum and Outdoor. It is typically
used for voice communication and often used to wire cable runs within
the walls of buildings.
•IBM Type 6 consists of two STP lengths of 26 AWG stranded wire for
data. Used in patch panels or to connect devices to/from wall jacks.
Attenuation for Type 6 cable is 150% of Type 1 cable (e.g., 66 m of
Type 6 =100 meters of Type 1).
•IBM Type 9 is similar to Type 1, but uses 26 AWG solid wire.
Attenuation for Type 9 cable is 150% of Type 1 cable (e.g., 66 m of
Type 9 = 100 meters of Type 1).
Impedance and Attentuation
The attenuation values shown Table B-2 include the attenuation of the
cables, connectors, patch panels, and reflection losses due to impedance
mismatches in the segment.
Table B-2. STP Cable Specifications
Type Freq. Impedance Attenuation
1 & 2 4 MHz
16 MHz 150Ω + 15%
150Ω + 15%
<22 dB/km (6.7 db/1000 ft.)
<45 dB/km (13.7 db/1000 ft.)
6 & 9 4 MHz
16 MHz 150Ω + 15%
150Ω + 15%
<33 dB/km (10 db/1000 ft.)
<66 dB/km (20 db/1000 ft.)