Networking Guide : Physical Media - Twisted Pair Cable Categories
Picture: Shielded Twisted Pair (STP)
STP (Shielded Twisted Pair) is a cable containing several twisted
pairs that has individual shields, an outer shield, and an
insulator. STP is more reliable than UTP. However STP
is less known because it is used only in situation where there is
complex cabling such as in factory building.
Picture: Screened Twisted Pair (ScTP)
ScTP (Screened Twisted Pair) is similar with STP but each twisted
pair has no individual shield.
Twisted pair cable is graded based on the number of twists per inch, its cable structure and
traffic carrying capacity into several categories, as follows:
| Category |
Type |
Bandwidth |
Typical applications |
| Cat 1 |
UTP |
< 1 MHz |
telephone |
| Cat 2 |
UTP |
1 MHz |
telephone |
| Cat 3 |
UTP, ScTP, STP |
16 MHz |
telephone, 10BaseT, 4 Mbps Token Ring |
| Cat 4 |
UTP, ScTP, STP |
20 MHz |
16 Mbps Token Ring, 10BaseT |
| Cat 5 |
UTP, ScTP, STP |
100 MHz |
10BaseT, 100BaseT |
| Cat 5e |
UTP, ScTP, STP |
350 MHz |
100BaseT, 1000BaseT |
| Cat 6 |
UTP, ScTP, STP |
550 MHz |
1000BaseT, ATM |
| Cat 7 |
ScTP, STP |
600 MHz |
10 Gbps network |
Table: Twisted Pair categories and their applications
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