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Q151713: Description of Twisted-Pair Category Types

Article: Q151713
Product(s): Windows for Workgroups and Windows NT Networking Issues
Version(s): MS-DOS:3.0; WINDOWS:3.11,95; winnt:3.5,3.51; :2.2c,3.11,3.11a,3.11b
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 08-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Workstation versions 3.5, 3.51 
- Microsoft Windows NT Server versions 3.5, 3.51 
- Microsoft LAN Manager, version 2.2c 
- Microsoft Windows for Workgroups version 3.11 
- Microsoft TCP/IP-32 for Windows for Workgroups, versions 3.11, 3.11a, 3.11b 
- Microsoft Windows 95 
- Microsoft Network Client for MS-DOS version 3.0 
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SUMMARY
=======

This article describes twisted-pair cabling and its role in the Electronic
Industries Association/Telecommunications Industries Association (EIA/TIA)568
Commercial Building Wiring Standard specification.

MORE INFORMATION
================

Twisted-pair consists of copper core wires surrounded by an insulator. Two wires
are twisted together to form a pair, and the pair forms the circuit that can
transmit data. A cable is a bundle of one or more twisted pairs surrounded by
another insulator and twisted together. Unshielded twisted-pair (UTP) is common
in a telephone network. Shielded twisted-pair (STP) provides protection against
external crosstalk by using braided metal shielding. The twisting prevents
interference problems, but must be maintained all the way to the connection
points.

Categories of Twisted-Pair
--------------------------

The EIA/TIA 568 specification standardizes the installation of wiring. It applies
to all UTP wiring schemes that work with Ethernet 10Base-T, token-ring, Private
Branch Exchange (PBX), Integrated Services Digital Network (ISDN), and Twisted
Pair-Physical Media Dependent (TP-PMD) networks. EIA/TIA 568 defines the
following cable categories:

Category 1: Unshielded twisted-pair (UTP) cable that is suited for voice but not
data. Most telephone cable installed before 1983 is Category 1 cable. Not widely
used anymore.

Category 2: UTP cable certified for data transmissions up to 4 Mbits/second.
Similar to IBM Cabling System Type 3 and is commonly installed as modern
telephone cable. This cable has four twisted pairs.

Category 3: UTP that supports 10-Mbits/sec transmission rates and is required for
token-ring (4 Mbits/sec) and 10-Mbits/sec Ethernet 10Base-T. The cable must have
four pairs and three twists per foot.

Category 4: UTP certified for 16 Mbits/sec transmission rates and is the lowest
grade acceptable for 16 Mbits/sec token-ring. The cable has four pairs.

Category 5: Defines 100-ohm, four-wire twisted-pair UTP copper cable that can
transmit data at 100 Mbits/sec to support technologies such as Fast Ethernet and
Asynchronous Transfer Mode (ATM), if installed according to specifications. The
cable is low-capacitance and exhibits low crosstalk. However, all components
must be Category 5 compliant; therefore, older modular connectors and jacks are
not suitable for Category 5 installations.

REFERENCES
==========

Sheldon, Tom. "LAN Times Encyclopedia of Networking." Berkeley: Osborne
McGraw-Hill, 1994.

Additional query words: cat1 cat2 cat3 cat4 cat5

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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search kbAudDeveloper kbWin95search kbZNotKeyword kbTCPIPSearch kbLanManSearch kbWFWSearch kbZNotKeyword3 kbNetworkClientSearch kbWFW311 kbLanMan220c kbNetworkClient300DOS kbTCPIP311 kbTCPIP311a kbTCPIP311b
Version           : MS-DOS:3.0; WINDOWS:3.11,95; winnt:3.5,3.51; :2.2c,3.11,3.11a,3.11b

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