category 3 cable
{{Short description|Unshielded twisted pair cable used in telephone wiring}}
Category 3 cable, commonly known as {{no wrap|Cat 3}} or station wire, and less commonly known as VG or voice-grade{{cite book | url=https://books.google.com/books?id=iJVFEAAAQBAJ&dq=category+3+cable+frequency&pg=PT142 | isbn=978-1-119-80696-7 | title=CompTIA Network+ Review Guide: Exam N10-008 | date=28 September 2021 | publisher=John Wiley & Sons }} (as, for example, in 100BaseVG), is an unshielded twisted pair (UTP) cable used in telephone wiring. It is part of a family of standards defined jointly by the Electronic Industries Alliance (EIA) and the Telecommunications Industry Association (TIA) and published in TIA/EIA-568-B.[https://grouper.ieee.org/groups/802/3/tutorial/july98/kish_070798.pdf Evolution of Cabling Standards: TIA/EIA, ISO/IEC, CENELEC]{{sps|date=November 2022}}[https://www.ieee802.org/3/minutes/jul99/B2_0799.pdf Standards Update]{{sps|date=November 2022}}
Although designed to reliably carry data up to {{nowrap|10 Mbit/s}},{{cite web |url=http://www.ciscopress.com/articles/article.asp?p=31276 |title=CCNA: Network Media Types |publisher=Cisco Systems |access-date=2017-09-05}} modern data networks run at much higher speeds, and {{no wrap|Cat 5e}} or better cable is generally used for new installations.{{cite book |title=Ethernet: the definitive guide |last=Spurgeon |first=Charles E |date=2000 |publisher=O'Reilly |isbn=9781565929524 |page=125}} Cat 3 cables may have 2, 3, 4, or more pairs.{{Cite web |last=Williams |first=Lawrence |date=2020-03-01 |title=Ethernet Cables Types: Cat 3, 5, 5e, 6, 6a, 7, 8 Wires Explained |url=https://www.guru99.com/ethernet-cables-types.html |access-date=2023-04-09 |website=www.guru99.com |language=en-US}}{{cite book |last1=Woodward |first1=Bill |title=Cabling: The Complete Guide to Copper and Fiber-Optic Networking |date=5 March 2014 |publisher=John Wiley & Sons |isbn=978-1-118-80738-5 |page=219 |url=https://www.google.com/books/edition/Cabling/BjYKAwAAQBAJ?hl=en&gbpv=1&pg=PA219 |access-date=18 November 2024 |language=en}}
Networking
{{no wrap|Cat 3}} was widely used in computer networking in the early 1990s for 10BASE-T Ethernet and, to a much lesser extent, for 100BaseVG Ethernet, Token Ring and 100BASE-T4. The original Power over Ethernet 802.3af specification supports the use of {{no wrap|Cat 3}} cable, but the later 802.3at Type 2 high-power variation does not.IEEE 802.3at-2009, clause 33.1.1c In some use cases and for short distances, Cat 3 may be capable of carrying 100BASE-TX (2 pairs) or even 1000BASE-T (4 pairs). Such use cases include hobbyist retrofitting short home telephone Cat 3 networks for Ethernet.[https://www.reddit.com/r/networking/comments/1w71mh/gigabit_over_cat3_wtf/ Gigabit over Cat3, WTF]{{sps|date=November 2022}}[https://www.youtube.com/watch?v=Bx98ACGSSZs CONVERTING HOME TELEPHONE WIRING TO ETHERNET]{{sps|date=November 2022}}[https://www.youtube.com/watch?v=hvUH-Cqtp6w How to convert your telephone line to an internet line: A complete guide]{{sps|date=November 2022}}
Dedicated 100BASE-T4 networks, supporting {{nowrap|100 Mbit/s}} over Cat 3, appear to have been a rarity as very few network interface controllers and switches were ever released. Some examples include the 3com 3C250-T4 Superstack II HUB 100, IBM 8225 Fast Ethernet Stackable Hub[https://www.ibm.com/common/ssi/cgi-bin/ssialias?appname=skmwww&htmlfid=897%2FENUS196-117&infotype=AN&mhq=IBM%20Network%20Station%208361%20Series%20100&mhsrc=ibmsearch_a&subtype=CA IBM 8225 Fast Ethernet Stackable Hub] and Intel LinkBuilder FMS 100 T4.{{cite web|url=https://techlibrary.hpe.com/docs/products/eos/3Com-End-of-Sale%20dates.pdf|title=3Com Product End of Sale dates|website=Hewlett Packard Enterprise}}{{cite web | url=https://manualzz.com/doc/3244934/intel-express-100base-t4-user-s-manual | title=Intel Express 100BASE-T4 User's Manual | website=Manualzz}} The same applies to network interface controller cards. Bridging 100BASE-T4 with 100BASE-TX required additional network equipment.
Replacement
Starting in the mid-1990s, new structured cabling installations were often built with the higher performing {{no wrap|Cat 5e}} cable required by 100BASE-TX. {{no wrap|Cat 5e}} or {{no wrap|Cat 6}} is now used for all modern structured cabling installations. Many large institutions have policies that any upgrade to a network using {{no wrap|Cat 3}} must involve upgrading to {{no wrap|Cat 5e}}.{{cite web |url=https://kb.wisc.edu/ns/page.php?id=13372 |title=University of Wisconsin – Standards for the Installation of New Data/Voice Jacks |accessdate=2013-09-17}}
See also
References
{{Reflist}}
External links
- [http://discountlowvoltage.blogspot.com/2009/11/how-low-voltage-cable-is-made-cat5e.html How Low Voltage Cable is Made - Cat5e, Cat6, Cat3 and OSP]
{{UTP Cable Standards}}
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