The EIA/TIA-568 wiring standard recognizes four (4) cable types and two (2)
telecommunications outlets. These standards are implemented in two specific
configurations at UCSB. Listed below are summaries of the relevant
cable standards and their implementation in the UCSB wiring standard. For
simplicity, references to measurement standards are indicated by ". . ."
and not detailed.
From EIA/TIA-568 reference page 10, Section 4.4 (Global Engineering Documents).
There are four types of cables that are recognized in the horizontal wiring
system. These cables include:
The cable consists of 24 AWG thermoplastic insulated
conductors formed into four individually twisted pairs and enclosed by a
thermoplastic jacket.
Note 1: Four-pair, 22 AWG cables which meet the transmission requirements of
this section may also be used.
Note 2: Four-pair, shielded twisted pair cables which meet the transmission
requirements of this section may also be used. The mechanical and physical
specifications are a subject for future study.
Note 3: For some LAN applications a higher grade medium may be required.
Insulated Conductor
The diameter over the insulation shall be 1.22 mm (0.048 in) max.
Pair Assembly
The pair twists of any pair shall not be exactly the same as any other pair.
The pair twist lengths shall be selected by the manufacturer to assure
compliance with the crosstalk requirements of this standard.
Color Codes
Pair 1 White-Blue (W-BL)* Blue (BL)"
Pair 2 White-Orange (W-O)* Orange (O)"
Pair 3 White-Green (W-G)* Green (G)"
Pair 4 White-Brown (W-BR)* Brown (BR)"
* (Wire insulation is white and a colored marking is added)
" (A white marking is optional)
Cable Diameter
The diameter of the completed cable shall be less than 6.35mm (0.25 in)
Breaking Strength
The ultimate breaking strength of the completed cable . . . 90 lb minimum.
Note: The maximum pulling tension should not exceed 25 lb to avoid
stretching.
Bending Radius
The cable tested . . . shall withstand a bend radius of 25.4 mm (1 in) at a
temperature of -20 C without jacket or insulation cracking
Transmission Requirements
DC Resistance
The resistance of any conductor, measured . . . , shall not exceed 28.6
ohms per 305 m (1000 ft) at or corrected to a temperature of 20 C.
DC Resistance Unbalance
The resistance unbalance between the two conductors of any pair shall not
exceed 5% when measured at or corrected to a temperature of 20 C in . . . .
Mutual Capacitance
The mutual capacitance of any pair at 1 kHz, measured . . . , shall not
exceed 20 nF per 305 M (1000 ft) at or corrected . . . .
TSB Enhanced Definition for Mutual Capacitance
The mutual capacitance of any pair at 1 kHz and measured at or corrected at
a temperature of 20C, shall not exceed 17 nF per 305 m (1000 ft) for category 4
and category 5 cables.
Capacitance Unbalance: Pair to Ground
The capacitance unbalance to ground at 1 kHz of any pair, measured . . . ,
shall not exceed 1000 pF per 305 m (1000 ft) at or corrected . . . .
Attenuation
The attenuation of any pair, measured or corrected . . . , shall not exceed
the following values:
Frequency Max Attenuation
(MHz) (db/1000')
0.064 2.8
0.256 4.0
0.512 5.6
0.772 6.8
1.0 7.8
4.0 17
8.0 26
10.0 30
16.0 40
TSB Enhanced Definition for Maximum Attenuation
The maximum attenuation of any pair shall be less than the values given in
the following table in the frequency range for 0.772 MHz to the highest
referenced frequency.
Maximum Attenuation dB per 1000 ft @ 20C
Frequency Category 3 Category 4 Category 5
MHz
0.064 2.8 2.3 2.2
0.256 4.0 3.4 3.2
0.512 5.6 4.6 4.5
0.772 6.8 5.7 5.5
1.0 7.8 6.5 6.3
4.0 17 13 13
8.0 26 19 18
10.0 30 22 20
16.0 40 27 25
20.0 - 31 28
25.0 - - 32
31.25 - - 36
62.5 - - 52
100 - - 67
Characteristic Impedance
The characteristics impedance, when measured according to . . . , shall
meet the following requirements:
Frequency (MHz) Characteristic Impedance (ohms)
0.064 125 +/- 15%
0.128 115 +/- 15%
0.256 110 +/- 15%
0.772 102 +/- 15%
1.0 - 16.0 100 +/- 15%
TSB Enhanced Definition for Characteristic Impedance
Both category 4 and category 5 cables shall have a characteristics impedance
of 100 Ohms +/- 15% in the frequency range from 1 MHz up to the highest
referenced frequency.
NOTE: The method of measuring "characteristic impedance" is
currently under study by the industry. As a result of structural
non-uniformities, the measured input impedance for an electrically long length
of cable will fluctuate as a function of frequency. This fluctuation is related
to the Structural Return Loss (SRL) for a cable that is terminated in its own
characteristic. Generally, the Enhanced Unshielded Twisted Pair (EUTP) cables in
categories 4 and 5 provide improved SRL performance.
Near-End Crosstalk (NEXT)
The NEXT coupling loss between any two pairs within a cable, tested
in . . . , shall be equal to or greater than the following values:
Frequency (MHz) NEXT Loss Worst Pair ( db @ 1000 ft)
0.15 54
0.772 43
1.0 41
4.0 32
8.0 28
10.0 26
16.0 23
TSB Enhanced Definition for NEXT Loss
The NEXT value at 0.772 MHz shall be 43 dB for category 3 cable, 58 dB for
category 4 cable and 64 dB for category 5 cable.
The following table gives values of worst pair NEXT Loss at specific
frequencies in the band of interest.
Frequency Category 3 Category 4 Category 5
MHz
0.150 54 68 74
0.772 43 58 64
1.000 41 56 62
4.000 32 47 53
8.000 28 42 48
10.000 26 41 47
16.000 23 38 44
20.000 - 36 42
25.000 - - 41
31.250 - - 40
62.500 - - 35
100.000 - - 32
NOTES: The NEXT Loss of patch cable shall be equivalent to the NEXT loss of
equal length of horizontal cable over the range of frequencies specified for any
given cable category. The NEXT Loss for connectors should be better than the
NEXT values for any given cable category specified above.
Measurement Precaution
The transmission measurements of mutual capacitance, capacitance unbalance,
characteristic impedance, attenuation, and NEXT shall be performed on cable
samples removed from the reel or packages. The test sample shall be
stretched along a non-conduction surface or supported in aerial spans such that
there is a minimum 1.0 in separation between any convolutions.
Note 1: On reel measurement is prohibited because parameters in Mutual Capacitance
and Attenuation can be up to 10% higher for cables measured on spools.
Note 2: When installed on a ground plant, metallic conduit, or other
conducting surface, the parameters of Mutual Capacitance and Attenuation may be higher
and the parameters of Attenuation may be lower.
The cable shall meet the requirements of EIA Interim
Standard Omnibus Specification, NQ-EIQ/IS-43 (Ref B1.9) and the following
detail specifications:
Specification and Cable Type Intended Application
(1) NQ-EIA/IS-43AB (Ref B1.11) Not for use in plenum areas
(2) NQ-EIA/IS-43AC (Ref B1.12) Not for use in plenum areas
May be used between floors
(3) NQ-EIA/IS-43AD (Ref B1.13) Not for use in plenum areas
May be used between floors
(4) NQ-EIA/IS-43AE (Ref B1.14) For use in non-plenum areas
(5) NQ-EIA/IS-43AF (Ref B1.15) Not for use in plenum areas
May be used between floors
(6) NQ-EIA/IS-43AG (Ref B1.16) For jumper and patch cord
applications only
UCSB Implementation Notes
UCSB Communications Services has used the IBM Type-2 cable specification
for workstation communications. This cable consists of four unshielded twisted
pairs as defined in the EIA-568 standard, but also includes two shielded twisted
pairs and a stranded shield surrounding all cable pairs.
This cable was first used in 1975 well before the introduction of
standards in unshielded twisted pair processing. Because the university
continues to demonstrate the need for higher speeds over twisted pair, and
manufacturer research continues in the implementation of 100 Megabit speeds over
copper (CDDI) in both unshielded and shielded cables, the use of Type-2
combination cable is continued.
The cable shall meet the specifications defined in IEEE
802.3 (10BASE2) (Ref B1.4).
UCSB Implementation Notes
The coaxial cable defined in the IEEE 802.3 is widely used on the
university campus. However, it is expected that future use of this cable will
be reduced and eventually eliminated. New building or major re-modeling will
NOT provide for this cable, but will instead provide the unshielded and shielded
twisted pair listed above.
There are three parts to the specification for fiber optic cable:
Optical Fiber Specifications
The fiber shall be multimode, graded-index optical fiber waveguide with
nominal 62.5/125um core/cladding diameter. The fiber shall comply with
ANSI/EIA/TIA-492AAAA (Ref B1.18).
Cable Transmission Performance Specifications
Each cabled fiber shall meet the graded performance specifications below:
Wavelength Maximum Attenuation Minimum Information
(nm) (dB/km) Transmission Capacity
(MHz-km)
850 3.75 160
1300 1.50 500
Attenuation shall be measured in accordance with EIA fiber optic test
procedures EIA/TIA-455-46, -61, or -53 (Ref B.1.39). Information transmission
capacity shall be measured in accordance with the following EIA/TIA-455-51 or
-30 (Ref B1.39). The cable shall be measured at 25 degrees C. +/- 5 degrees C.
Physical Cable Specifications
The mechanical and environmental specifications for indoor fiber optic cable
shall be in accordance with ANSI/ICEA S-83-596 (Ref B1.40).
Telecommunications Outlet Specification
100-ohm UTP Cable
Each four-pair cable shall be terminated in an eight-position modular jack
in the work area. The 100-ohm UTP telecommunications outlet shall meet the
requirements described in EIA/TIA-570 (Ref. B1.2) and EIA/TIA-TSB-31 (Ref
B1.37).
UCSB Implementation Notes
UCSB Communications Services terminates the four unshielded twisted
pairs on two (2) jacks - one RJ-11 for voice and one RJ-45 for data (10BaseT).
This is done to streamline the attachment of modular cables for voice and data
devices without the use of eight-wire Y cables to access two sets of two pairs.
150 Ohm STP Cable
The telecommunications connector used for terminating the 150-ohm STP cable
shall be that specified by ANSI/IEEE 802.5 (Ref B1.5)v for the media interface
connector. This connector shall be hermaphroditic in design so that identical
units will mate when oriented 180 degrees with respect to each other.
UCSB Implementation Notes
The two shielded twisted pairs (STP) contained in the Type-2 cable
sheath are terminated on a separate RJ-45 connector. The specification as
written calls for a hermaphroditic connector such as the IBM Token-Ring
connector. IBM now supports token-ring using the RJ-type connector.
DCC
