Category 1 cable, also known as Cat 1, Level 1, or voice-grade copper, is a grade of
unshielded twisted pair
Twisted pair cabling is a type of wiring used for communications in which two conductors of a single circuit are twisted together for the purposes of improving electromagnetic compatibility. Compared to a single conductor or an untwisted ba ...
cabling designed for
telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
communications, and at one time was the most common
on-premises wiring
On-premises wiring (customer premises wiring) is customer-owned telecommunication transmission or distribution lines. The transmission lines may be metallic (copper) or optical fiber, and may be installed within or between buildings.
Premises ...
. The maximum frequency suitable for transmission over Cat 1 cable is 1 MHz,
but Cat 1 is not currently considered adequate for data transmission (though it was at one time used for that purpose on the
Apple Macintosh
The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc., Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and ...
starting in the late 1980s in the form of
Farallon Computing's//NetTopia's PhoneNet, an implementation of Apple's
LocalTalk
LocalTalk is a particular implementation of the physical layer of the AppleTalk networking system from Apple Computer.
LocalTalk specifies a system of shielded twisted pair cabling, plugged into self-terminating transceivers, running at a rate ...
networking hardware standard).
Although not an official category standard established by TIA/EIA, Category 1 has become the de facto name given to Level 1 cables originally defined by
Anixter International
Anixter International Inc. is a company based in Glenview, Illinois
Glenview is an incorporated village located in Cook County, Illinois, United States, approximately 15 miles northwest of the Chicago Loop. Per the 2020 census, the populatio ...
, the distributor. Cat 1 cable was typically used for networks that carry only voice traffic, for example telephones. Official
TIA/EIA-568
ANSI/TIA-568 is a technical standard for commercial building cabling for telecommunications products and services. The title of the standard is ''Commercial Building Telecommunications Cabling Standard'' and is published by the Telecommunications ...
standards have only been established for cables of
Category 3 ratings or above.
References
External links
CCNA: Network Media Types
Signal cables
Local loop
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