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Category 5 cable

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Category 5 cable that is partiallystrippedand showing its fourtwisted pairs(eight wires)

Category 5 cable(Cat 5) is atwisted paircable forcomputer networks.Since 2001, the variant commonly in use is theCategory 5especification (Cat 5e). The cable standard provides performance of up to 100 MHz and is suitable for most varieties ofEthernet over twisted pairup to2.5GBASE-T[1][2][3][4]but more commonly runs at1000BASE-T(Gigabit Ethernet) speeds. Cat 5 is also used to carry other signals such astelephoneandvideo.

This cable is commonly connected usingpunch-down blocksandmodular connectors.Most Category 5 cables areunshielded,relying on thebalanced linetwisted pair design anddifferential signalingfor noise suppression.

Standards

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Category 5 is currently defined inISO/IEC 11801,IEC 61156andEN 50173,though it was originally defined inANSI/TIA/EIA-568-A(with clarification in TSB-95).[5]These documents specify performance characteristics and test requirements forfrequenciesup to 100 MHz.

The cable is available in both stranded and solid conductor forms. The stranded form is more flexible and withstands more bending without breaking.Patch cablesare stranded. Permanent wiring used instructured cablingis solid. The category and type of cable can be identified by the printing on the jacket.[6]

The Category 5 specification requires conductors to be pure copper. There has been a rise in counterfeit cables, especially of the copper-clad aluminum (CCA) variety.[7]This has exposed the manufacturers and installers of such fake cable to legal liabilities.[8]

Variants and comparisons

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The Category 5e specification improves upon the Category 5 specification by further mitigatingcrosstalk.[9]Thebandwidth(100 MHz) and physical construction are the same between the two,[10]and most Cat 5 cables actually happen to meet Cat 5e specifications even though they are not certified as such.[11]Category 5 was deprecated in 2001 and superseded by the Category 5e specification.[12]

TheCategory 6specification improves upon the Category 5e specification by extending frequency response and further reducing crosstalk. The improved performance of Cat 6 provides 250 MHz bandwidth.[12]Category 6A cable provides 500 MHz bandwidth. Both variants arebackward compatiblewith Category 5 and 5e cables.

Termination

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TIA/EIA-568-B.1-2001T568A Wiring
Pin Pair Wire Color
1 3 1 Pair 3 Wire 1white/green
2 3 2 Pair 3 Wire 2green
3 2 1 Pair 2 Wire 1white/orange
4 1 2 Pair 1 Wire 2blue
5 1 1 Pair 1 Wire 1white/blue
6 2 2 Pair 2 Wire 2orange
7 4 1 Pair 4 Wire 1white/brown
8 4 2 Pair 4 Wire 2brown
TIA/EIA-568-B.1-2001T568B Wiring[13]
Pin Pair Wire Color
1 2 1 Pair 2 Wire 1white/orange
2 2 2 Pair 2 Wire 2orange
3 3 1 Pair 3 Wire 1white/green
4 1 2 Pair 1 Wire 2blue
5 1 1 Pair 1 Wire 1white/blue
6 3 2 Pair 3 Wire 2green
7 4 1 Pair 4 Wire 1white/brown
8 4 2 Pair 4 Wire 2brown
A Cat 5e dual-port wall-mount assembly showing the two wiring schemes: A forT568A,B forT568B
Category 5patch cableinT568Bwiring

Cable types, connector types and cabling topologies are defined byANSI/TIA-568.Category 5 cable is nearly always terminated with8P8C modular connectors(often referred to incorrectly asRJ45connectors[14][15][16]). The cable is terminated in either theT568Ascheme or theT568Bscheme. The two schemes work equally well and may be mixed in an installation so long as the same scheme is used on both ends of each cable.

Applications

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Category 5 cable is used in structured cabling forcomputer networkssuch asEthernet over twisted pair.The cable standard prescribes performance parameters for frequencies up to100 MHzand is suitable for10BASE-T,100BASE-TX(Fast Ethernet),1000BASE-T(Gigabit Ethernet), and2.5GBASE-T.10BASE-Tand100BASE-TXEthernet connections require two wire pairs. 1000BASE-T and faster Ethernet connections require four wire pairs. Through the use ofpower over Ethernet(PoE),powercan be carried over the cable in addition to Ethernet data.

Cat 5 is also used to carry other signals such astelephonyandvideo.[17]In some cases, multiple signals can be carried on a single cable; Cat 5 can carry two conventional telephone lines as well as 100BASE-TX in a single cable.[18][19][20][21][22]TheUSOC/RJ-61wiring standard may be used in multi-line telephone connections. Various schemes exist for transporting both analog and digital video over the cable.HDBaseT(10.2 Gbit/s)is one such scheme.[23]

Characteristics

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The use ofbalanced lineshelps preserve a highsignal-to-noise ratiodespite interference from both external sources and crosstalk from other pairs.

Electrical characteristics for a commercially available Cat 5e UTP cable product
Property Nominal Tolerance Unit ref
Characteristic impedance,1–100MHz 100 ± 15 Ω [24]
Characteristicimpedance@ 100 MHz 100 ± 5 Ω [24]
DC loop resistance ≤ 0.188 Ω/m [24]
Propagation speedrelative to thespeed of light 0.64 1 [24]
Propagation delay 5.30 ns/m [24]
Delay skew< 100 MHz < 0.20 ns/m [24]
Capacitanceat800 Hz 52 pF/m [24]
Max tensile load, during installation 100 N [24]
Wire diameter (24AWG;0.205 mm2)) 0.51 mm [24]
Operating temperature −55 to +60 °C [24]
MaximumDCoperating voltage
(PoEuses max 57 V)[25]		 125 V [26]

Insulation

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Outer insulation is typicallypolyvinyl chloride(PVC)[27]orlow smoke zero halogen(LS0H).[citation needed]

Example materials used as insulation in the cable[28]
Acronym Material
PE Polyethylene
FP Foamed polyethylene
FEP Fluorinated ethylene propylene
FFEP Foamed fluorinated ethylene propylene
AD/PE Air dielectric/polyethylene
LSZH or LS0H Low smoke, zerohalogen
LSFZH or LSF0H Low smoke and fume, zero halogen

Bending radius

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Most Category 5 cables can be bent at any radius exceeding approximately four times the outside diameter of the cable.[29][30]

Maximum cable segment length

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The maximum length for a cable segment is 100 meters (330 ft) per TIA/EIA 568-5-A.[31]If longer runs are required, the use of active hardware such as a repeater or switch is necessary.[32][33]The specifications for 10BASE-T networking specify a 100-meter length between active devices.[34]This allows for 90 meters of solid-core permanent wiring, two connectors and two stranded patch cables of 5 meters, one at each end.[35]

Conductors

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Since 1995, solid-conductor UTP cables for backbone cabling is required to be no thicker than 22American Wire Gauge(AWG) and no thinner than 24 AWG, or 26 AWG for shorter-distance cabling. This standard has been retained with the 2009 revision of ANSI TIA/EIA 568.[36]

Although cable assemblies containing four pairs are common, Category 5 is not limited to four pairs. Backbone applications involve using up to100 pairs.[37]

Individual twist lengths

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The distance per twist is commonly referred to as pitch. Each of the four pairs in a Cat 5 cable has a differing pitch to minimizecrosstalkbetween the pairs. The pitch of the twisted pairs is not specified in the standard.

Environmental ratings

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United States and Canada fire certifications[38]
Class Phrase Description Standards
LSZH Communications low-smoke zero halogen NES‑711, NES‑713, MIL‑C‑24643, UL 1685
CMP Communications plenum Insulated with fluorinated ethylene propylene (FEP) and polyethylene (PE) and jacketed with low-smoke polyvinyl chloride (PVC), due to better flame test ratings. CSAFT6[39]orNFPA262 (UL910)
CMR Communications riser Insulated with high-density polyolefin and jacketed with low-smoke polyvinyl chloride (PVC).

UL1666

CMG Communications general purpose CSA FT4
CM Communications Insulated with high-density polyolefin, but not jacketed with PVC and therefore is the lowest of the three in flame resistance. UL 1685 (UL 1581, Sec. 1160) Vertical-Tray
CMX Communications residential UL 1581, Sec. 1080(VW-1)
CMH CSA FT1

Some cables areUV-ratedorUV-stablemeaning they can be exposed to outdoorUVradiation without significant degradation.[40]

Plenum-rated cables are slower to burn and produce less smoke than cables using a mantle of materials like PVC. Plenum-rated cables may be installed inplenum spaceswhere PVC is not allowed.[41][self-published source?]

Shielded cables (FTP or STP) are useful for environments where proximity toRF equipmentmay introduceelectromagnetic interference,and can also be used whereeavesdroppinglikelihood should be minimized.

References

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  1. ^Cooney, Michael (2016-09-27)."IEEE sets new Ethernet standard that brings 5X the speed without disruptive cable changes".Network World.Retrieved2021-01-19.
  2. ^Anthony, Sebastian (2016-09-29)."Here comes 5Gbps networking over standard cables".Ars Technica.Retrieved2021-01-18.
  3. ^Smith, Ryan."At Last, a 2.5Gbps Consumer Network Switch: QNAP Releases QSW-1105-5T 5-Port Switch".anandtech.Retrieved2021-01-19.
  4. ^"IEEE P802.3bz 2.5/5GBASE-T Task Force".ieee802.org.Retrieved2021-01-19.
  5. ^"Additional Transmission Performance Guidelines for 4-pair 100 v category 5 Cabling"(PDF).Archived fromthe original(PDF)on 2013-10-05.Retrieved2013-05-12.
  6. ^"Ethernet Cable Identification and Use".Donutey. Archived fromthe originalon 2011-07-10.Retrieved2011-04-01.
  7. ^"APPLICATION NOTE Copper Clad Aluminum(CCA) Cables".Fluke Networks. 26 December 2013.Retrieved2021-04-07.
  8. ^"Potential Legal Liabilities for Manufacturers and Installers of Category Communications Cables Made with Copper Clad Aluminum Conductors".Communications Cable and Connectivity Association, Inc. (CCCA).Retrieved2021-04-07.
  9. ^"Understanding Cat - 5 Cables"(PDF).Satelliete & Cable TV. Archived fromthe original(PDF)on 2013-05-15.Retrieved2013-01-05.
  10. ^"Cat5 Spec, cat6 specs, cat7 spec - Definitions, Comparison, Specifications".TEC Datawire. Archived fromthe originalon 2013-07-19.Retrieved2013-01-05.
  11. ^"Comparison between CAT 5, CAT 5e, CAT 6, CAT 7 Cables".Archived fromthe originalon 2020-02-13.
  12. ^ab"Voice and Data Cabling & Wiring Installations".Retrieved2013-05-12.
  13. ^"ANSI/TIA/EIA-568-B.1-2001 Approved: April 12, 2001; Commercial Building Telecommunications Cabling Standard Part 1: General Requirements"(PDF).090917 nag.ru
  14. ^Trulove 2005,pp. 23, 132: ‘Designing LAN Wiring Systems:The 8-pin modular jack is sometimes referred to as an "RJ-45", because the connector/jack components are the same. However, RJ-45 actually applies to a special purpose jack configuration that is not used in LAN or standard telephone wiring. […]Work Area Outlets:Modular jacks are often referred to as "RJ-45" jacks. This is not really the correct moniker, although it is in very common use.’
  15. ^Oliviero, Andrew; Woodward, Bill (July 20, 2009). "Connectors".Cabling: The Complete Guide to Copper and Fiber-Optic Networking(4th ed.).Sybex.p. 294.ISBN978-0-470-47707-6.The RJ (registered jack) prefix is one of the most widely (and incorrectly) used prefixes in the computer industry; nearly everyone, including people working for cabling companies, is guilty of referring to an eight-position modular jack (sometimes called an 8P8C) as an RJ-45.
  16. ^Semenov, Andrey B.; Strizhakov, Stanislav K.; Suncheley, Igor R. (October 3, 2002). "Electrical Cable Connectors".Structured cable systems.Springer.p. 129.ISBN3-540-43000-8.The traditional 8-contact connector, which is called Western Plug, 8PMJ (8-position modular jack), 8P8C (8 position 8 conductor), or somewhat incorrectly RJ-45, is used widely in SCS practice.
  17. ^"Transmitting video over CAT 5 cable".EE Times.2005-06-08.Retrieved2013-12-07.
  18. ^"Hack your House: Run Both Ethernet and Phone Over Existing Cat 5 Cable".Retrieved2016-08-15.
  19. ^"LAN and Telephones".zytrax. October 21, 2015.Since 10base-T or 100base-TX wiring uses 2 pairs (4 wires) and each analog phone connection uses a single pair (2 wires) you can, subject to limitations, run 2 telephone connections and LAN traffic on category 5(e) wiring.
  20. ^"Cable Sharing in Commercial Building Environments: Reducing Cost, Simplifying Cable Management, and Converging Applications onto Twisted-Pair Media".Siemon.Retrieved2014-04-28.
  21. ^"RJ45/RJ11 Network Cable Splitters for Ethernet and Phone Line Sharing".carry one old fashioned analog telephone signal and one 10/100 Mbps Ethernet signal by the same single network cable.
  22. ^"ATS 10/100 Base T Splitter Adapters".Duxcw. Archived fromthe originalon 2015-01-07.Retrieved2014-08-17.
  23. ^HDBaseT Alliance(January 9, 2013)."HDBaseT Alliance Shows the Future of Connected Home Entertainment at CES 2013".Retrieved2017-10-31.
  24. ^abcdefghij"SuperCat OUTDOOR CAT 5e U/UTP"(PDF).Archived fromthe original(PDF)on 2012-03-16.
  25. ^IEEE 802.3at-2009 Table 33-11
  26. ^"Copper Data Cables"(PDF).p. 6. Archived fromthe original(PDF)on 2006-06-25.
  27. ^"Specialized Ethernet Cable"(PDF).CableWholesale. August 2016.
  28. ^"UTP-STP Cable"(PDF).Retrieved2016-08-18.
  29. ^"Selecting coax and twisted-pair cable".Electronic Products. Archived fromthe originalon 2009-02-01.
  30. ^"Category 5".Archived fromthe originalon 2013-06-01.Retrieved2013-05-12.
  31. ^"The Evolution of Copper Cabling Systems from Cat 5 to Cat 5e to Cat 6"(PDF).Panduit.2004-02-27. Archived fromthe original(PDF)on 2013-03-14.Retrieved2013-05-12.
  32. ^"UTP technology"(PDF).Extron Electronics.2001. Archived fromthe original(PDF)on 2013-05-11.Retrieved2013-05-12.
  33. ^"CAT 5e Cable Wiring Schemes".B&B Electronics. Archived fromthe originalon 2012-10-05.
  34. ^"IEEE Std 802.3-2008" (Document). Institute of Electrical and Electronics Engineers. 2008. Table 13-1.
  35. ^"Horizontal Cabling".The Network Encyclopedia.Retrieved2013-05-12.
  36. ^"ANSI/TIA/EIA-568-B.2-2001, Commercial Building Telecommunications Cabling Standard"(PDF).p. 6 ¶4.3.2.
  37. ^As noted in ANSI/TIA/EIA-568-B-2 standard for backbone applications
  38. ^"Technical Information"(PDF).Belden.p. 22.20. Archived fromthe original(PDF)on 2006-10-20.
  39. ^"CSA Flame Test Ratings".Retrieved2013-05-12.
  40. ^CIBSE (2000)."Understanding Building Integrated Photovoltaics - CIBSE TM25 - 5.8 Legislation. The Chartered Institution of Building Services Engineers (CIBSE)".app.knovel.Retrieved2022-03-29.
  41. ^"What are the differences between PVC, riser and plenum-rated cables?".Archived fromthe originalon 2011-07-13.[self-published source]

Further reading

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  • Trulove, James (December 19, 2005),LAN wiring(3rd ed.), McGraw-Hill Professional,ISBN0-07-145975-8
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