A Specifications and Cabling Requirements
54
Cabling Requirements
The cable, quality, distance, and connectors must comply with the Electronic Industries
Association/Telecommunications Industries Association (EIA/TIA) 568 Commercial Building
Wiring Standard and the Technical Services Bulletin TSB38 standards.
Twisted-Pair Cable
Twisted-pair cable consists of copper wires surrounded by an insulator. Two wires are
twisted together (the twisting prevents interference problems) to form a pair, and the pair
forms a circuit that can transmit data. A cable is a bundle of one or more twisted pairs
surrounded by an insulator.
Unshielded twisted pair (UTP) is the most commonly used type of twisted-pair cable.
Shielded twisted pair (STP) provides protection against crosstalk. Twisted-pair cable is now
commonly used in Ethernet, Fast Ethernet, and other network topologies.
The EIA/TIA defines five categories of unshielded twisted-pair cable.
Environment
Operating temperature 32˚ to 158˚ F (0˚ to 70˚ C)
Storage temperature –22˚ to 194˚ F (–30˚ to 90˚ C)
Operating humidity 10 to 90% noncondensing
Storage humidity 10 to 90% noncondensing
Altitude –984 ft to 9,840 ft (–300 to 3,000 m)
Standards Conformance
■ IEEE 803.3x flow control
■ Microsoft PC98
■ PCI 2.1
■ DMI 2.0 s
Category Use
1 Traditional telephone cable.
2 Data transmission up to 4 MHz.
3 Voice and data transmission up to 25 MHz. The cable typically has four pairs of wires.
Category 3 is the most common type of installed cable found in older corporate
wiring schemes.
4 Voice and data transmission up to 33 MHz. The cable normally has four pairs of wire.
This grade of UTP is not common.
5 Voice and data transmission up to 125 MHz. The cable normally has four pairs of
copper wire and three twists per foot. Category 5 UTP is the most popular cable used
in new installations today.
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