Ever wonder what the difference is in all
of the cable types. Well, we have compiled a number of articles and
information about all of the different types of cables you will encounter
in most SOHO (Small Office home Office) environments as well as some
larger installations. Please look through the following information
to find out what you need to know to hook up all of your devices.
Computer
Networking Cable
Today, computers are linked into a network using 4-pair
unshielded twisted pair cable called 10Base T. An older method, 10Base
2, used coax cables daisy-chained form room to room and is being phased
out.
When you use 10BaseT, cables are home run from each computer
back to the server where a hub is required to connect all the cables
together. Inexpensive hubs for up to 8 computers can be purchased for
about $150.
The type of cable to use for 10 Base T is critical. Category
5 cable or better is required. Cat 5 cable is rated for up to 100Mbps
data transfer speed which is the data transfer speed of Fast-Ethernet
network cards. A new cable, Cat 5e is rated for 1000Mbps data transfer
rate, which is the new Gigabit Ethernet speed.
To be completely prepared for future standards use Cat
5e or higher, if you think you can live with current technology use
Cat 5 cable. Wire your cables well away from AC wire and fluorescent
lights.
10BASE-2 (Thin net)
An 802.3 standard for LAN. 10 megabit/second over distances up to 185
meters (607 ft.) on thin coaxial cable. The specifications allow 30
or fewer MAUs per cable segment spaced at no less than 0.5 meter (1.64
ft.). Both ends of the segment must be terminated with a 50 ohm terminator.
Earth grounding of the segment shield must take place at only one point
on the cable
10BASE-5 (Thick net) An 802.3
standard for LAN. 10 megabit/second over distances up to 500 meters
(1640 ft.) on thick coaxial cable. The specifications allow 100 or fewer
MAU attachments, spaced at multiples of 2.5 meters (8.2 ft.) measured
accurately from the cable end (50 ohm terminator included). At any instant
the signal can be in one of three states: transmitting a 0 bit (-0.85v),
transmitting a 1 bit (0.85v) or idle (0 volts)
10BASE-FL (Fiber link) An 802.3
standard for LAN. 10 megabit/second over distances up to 2000 meters
(6560 ft.) on multimode duplex fiber optic cable (duplex refers to cable
pairs) in a point-to-point link which directly attaches two MAUs.
10BASE-T (Twisted pair) An 802.3
standard for LAN. 10 megabit/second over distances up to 100 meters
(328 ft.) Cat 3 cable (or better) should be used. The most common connector
used is RJ-45. 10Base-T uses only two pair in the cable. See the cable
page on this site
100BASE-Fx (Fast Ethernet Fiber)
An 802.3 standard for LAN. 100 megabit/second over distances up to 2000
meters (6560 ft.) on multi-mode fiber, otherwise similar to 10BASE-FL.
100BASE-Tx (Fast Ethernet) An
802.3u/D2 standard for 100 megabit/second. Packets are identical to
802.3 packets (with bit-times 1/10 the time), but the nature of CSMA/CD
requires that the overall radius of the net be limited to 1/10 the size
of 10Mbps Ethernet. Single-hub networks allow up to 325 meters (e.g.
225 meters of fiber for one link and 100 meters of twisted pair for
any other link). Extension of the net beyond this would require a switch
or router. 100Base-Tx uses only two pair in the cable. See The Ethernet
Straight Thru patch cord.
100VG-AnyLAN (Voice Grade at any
LAN) An 802.12 standard for 100 megabit/second. This standard eliminates
packets collisions and permits more efficient use of network bandwidth.
It does this by using the DPA scheme instead of the CSMA/CD scheme used
in 10BASE-T and 100BASE-Tx. It also requires users to install new network
adapter cards, hubs and switches. Although the name AnyLAN is given
because it can transfer either Ethernet and Token Ring frames, both
may not be used on the same segment; they must be physically segregated
on separate segments by a device such as a router.
1000BASE-CX (Gigabit Ethernet)
An IEEE 802.3z standard for 1 Gigabit/second up to 25 meter. 1000BASE-CX
is a standard intended for use in a switching closet or computer room
as a short jumper. Uses a special balanced 150-ohm cable, called twinax
cable.
1000BASE-LX (Gigabit Ethernet Long-wavelength)
An IEEE 802.3z standard for 1 Gigabit/second up to 3000 meter. Uses
Singlemode Fiber and requires SC connectors for terminating the fiber-optic
cable.
1000BASE-SX (Gigabit Ethernet Short-wavelength)
An IEEE 802.3z standard for 1 Gigabit/second. Uses Multimode Fiber 50
µm core (max 300 m) or 62,5 µm core (max 500 m) and requires SC connectors
for terminating the fiber-optic cable.
1000BASE-T (Gigabit Ethernet)
An IEEE 802.3ab standard for 1 Gigabit/second up to 100 meter using
the Cat 5 cable standard. The data will be transported over four pairs
simultaneously from both ends of each pair. Each pair carries a 250
Mb/s full duplex data stream (approved by the IEEE-SA Standards Board
on 26-jun-1999).
Category
Specifications
EIA/TIA Category Specification provide for the following cable transmission
speeds with specifications (Note prior to Jan94 UL and Anixter developed
a LEVEL system which has been dropped or harmonized with the CATEGORY
system)
Category 1 = No performance criteria
Category 2 = Rated to 1 MHz (used for telephone wiring)
Category 3 = Rated to 16 MHz (used for Ethernet 10Base-T)
Category 4 = Rated to 20 MHz (used for Token-Ring, 10Base-T)
Category 5 = Rated to 100 MHz (used for 100Base-T, 10Base-T)
Category 5e = Same as Category 5, except that it is made to somewhat more stringent standards. Category 5 E is recommended for all new installations, and was designed for transmission speeds of up to 1 gigabit per second (Gigabit Ethernet over Copper).
Category 6 =
Same as Category 5e, except that it is made to somewhat more stringent standards.
Wiring Schemes (Please refer here for the source of this information)
568A & 568B Wiring Schemes
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| 568A Standard |
This standard was published in July of 1991. The purpose of EIA/TIA 568A, was to create a multiproduct, multivendor, standard for connectivity. Prior to the adoption of this standard, many "proprietary" cabling systems existed. The 568 "standard" is not to be confused with 568A or 568B wiring schemes, which are themselves, part of the "568A standard". |
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| 568A & 568B Wiring Schemes |
Referring to a jack or a patch panel's wiring connection, refer to either the 568A, or 568B wiring scheme, which dictates the pin assignments to the pairs of cat 5E cable. The 568A has an advantage over the other. It is when one end of a segment is connected to a modular device, and the other end to a punch block. In which case, the 568A has the advantage of having a more natural progression of pairs at the punch block side. |
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For those who are not familiar with telephony, tip (T) refers to the positive (+) side, and ring (R) refers to the negative side of the circuit. The white/blue pair (the first pair in the cable) consists of two wires that are twisted together. They are the white/blue (tip) and the blue/white (ring). The white/blue wire is predominately white with a blue stripe. The blue/white is the inverse, predominately blue with a white stripe.
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568A Wiring
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| Pair # |
Wire |
Pin # |
| 1 - White/Blue |
White/Blue |
5 |
| Blue/White |
4 |
| 2 - White/Orange |
White/Orange |
3 |
| Orange White |
6 |
| 3 - White/Green |
White/Green |
1 |
| Green/White |
2 |
| 4 - White/Brown |
White/Brown |
7 |
| Brown/White |
8 |
|
|
|
|
568B Wiring
|
|
|
| Pair # |
Wire |
Pin # |
| 1) White/Blue |
White/Blue |
5 |
| Blue/White |
4 |
| 2) White/Orange |
White/Orange |
1 |
| Orange White |
2 |
| 3) White/Green |
White/Green |
3 |
| Green/White |
6 |
| 4) White/Brown |
White/Brown |
7 |
| Brown/White |
8 |
|
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There is a great deal of cabling information available from theLANshack site . |
The Crossover
Cable
This cable is used for connecting two computers
together without the use of a hub in between them. The output of one
device is connected directly to the input of the other device. Please
note that the pins used in the cable are 1, 2, 3 and 6. The other pins
are not used in Ethernet crossover cables.
The Straight-Thru
Cable
This cable is used for connecting your
computer or other network device to a switch or hub. Please note
that the pins used in the cable are 1, 2, 3 and 6. The other pins are
not used in Ethernet straight-thru cables.
Typical
Wiring in an office environment
Wiring Layout ......Wiring Closet.............. ....User
Work Area.... [HUB]<=====>[PANEL]+=====+[BLOCK]+==============+[WALL]<=====>[STATION]
Where ...
HUB = concentrator
PANEL = RJ-45 Modular Patch Panel
BLOCK = Telco Splice Block (Typically 25-pair)
Crossconnect: NorTel BIX1A, AT&T 110 and similar crossconnect blocks
accommodate 4-pair, 25-pair or larger cables on the same mount. The
same type of mount can be used for the voice field as well as data.
Telephone-only (66) blocks are seldom used except for low-speed data
circuits such as are used for IBM 3270 terminals. The newer types
of crossconnect mentioned above cost about the same and accommodates
growth much better. (The standard AT&T 110 and its BIX equivalent
are rated at Cat 5).
LOBE CABLE = Cable run from user wall plate to wiring closet
WALL = User area wall face plate
STATION = User workstation network adapter
=====> = RJ-45 connector
=====+ = Punch down termination (also called an insulation- displacement/displacing
connector, or IDC).
Crossconnect Field Colors
The color of label used on a crossconnect field identifies the
field's function. The cabling administration standard (CSA T-528
& EIA-606) lists the colors and functions as:
Blue Horizontal voice cables
Brown Interbuilding backbone
Gray Second-level backbone
Green Network connections & auxiliary circuits
Orange Demarcation point, telephone cable from Central Office
Purple First-level backbone
Red Key-type telephone systems
Silver or White Horizontal data cables, computer & PBX equipment
Yellow Auxiliary, maintenance & security alarms
UTP (Unshielded
Twisted Pair) Cable Applications
UTP cable is found extensively in the so-called local loop of the
telephone company. The local loop is that wiring that connects your
house to the telephone companies local ``switch'' building. This cable
is typically under 18,000 feet in length and suffices for transmission
of telephone signals. New kinds of special digital modems for ISDN
and xDSL data services can sometimes (depending upon the length and
nearby interfering sources) be used to move data at higher speeds
than a telephone signal based modem. For example 128 Kbps (ISDN, bi-directional)
to 1.544 Mbps (HDSL in one direction) can be achieved using (now)
relatively low cost and very sophisticated special connection devices.
Rates as high as 52 Mbps (VDSL in one direction) can be obtained if
the length of the local loop is below 3,280 feet.
The telephone companies also make extensive use of UTP for movement
of digitized groups of voice signals between their switching stations.
The T1 signal unidirectionally carries groups of 24 voice channels
in a 1.544 Mbps digital format over 6000 ft. distances between regenerators
circuits.
UTP is also found in the walls (in spaces called plenums) throughout
most buildings. It is used to complete the local loop from the building
entrance to the telephone wall plates in the rooms. UTP has found
extensive use as a cheap medium for the distribution of medium speed
computer network data connectivity.
Ethernet data is routinely transmitted in a signaling system known
as 10Base-T Ethernet in which UTP cable is used for distances up to
100 m (328 feet).
UTP can be made with a variety of materials, sizes of conductors
and numbers of pairs inside a single cable. A particularly high quality
UTP is called UTP-5. This cable type has been used to support 100
Mbps Ethernet transmissions over distances of 100 m
STP (Shielded
Twisted Pair) Cable Applications
STP is used extensively by the telephone company for moving large
groups (96) of digitized telephone conversations over distances of
6000 feet between ``repeaters'' that receive and re-transmit the cable
for the next such hop, to span the distance of several miles between
telephone company switching stations. The so-called T2 connection
involves digital data transmission at speeds of 6.312 Mbps. High quality
STP has been applied by the telephone companies for transmission rates
as high as 8.448 Mbps in Europe.
Coaxial Cable
Applications
As seen before, coaxial cable is used where ever there exists a need
for long distance, low attenuation and low noise transmission of information.
Probably everyone is familiar with the use of coaxial cable for the
transmission of a hundred TV channels into the home via CATV coaxial
cable, since, 70% of all homes in the USA have CATV service and now
even more cable is being used to bring Ethernet networking to the home
network user. .
These cables provide bandwidth of nearly 1 GHz (that is 1000 MHz)
into the home. These same cables are capable of transmitting many Gbps
of information into those same homes. In fact, the research and test
deployment of CATV based Internet delivery systems is currently a growth
industry.
In many businesses today coaxial cable is the major delivery system
for 10 and 100 Mbps Ethernet computer network data signals, for hop
distances of 500 m (1640 ft) and 185 m (607 ft) respectively for the
larger and smaller diameter cables (RG-8 and RG-58) that are in common
use.
The telephone companies also resort to coaxial cable to bridge larger
distances with higher rate digital connections. One example is the use
of coaxial cable to transmit 140 Mbps data signals between telephone
switch buildings with a hop distance of up to 2 km (6,562 ft).
Fiber
Optic Cable
Multimode (MM) Fiber
Step index or graded index fiber. In North America the most common
size is 62.5/125; in Europe, 50/125 is often used. These numbers
represent the diameter of the core (62.5) and diameter of the cladding
(125) in microns. Multimode fiber is typically used in applications
such as local area networks, at distances less than 2 km.
Single Mode (SM) Fiber
Single mode fiber has a very small core. Typical values are 5-10
microns. Single mode fiber has a much higher capacity and allows
longer distances than multimode fiber. Typically used for wide area
networks such as telephone company switch to switch connections
and cable TV (CATV).
Loose Buffer
The fiber is contained in a plastic tube for protection. To give
better waterproofing protection to the fiber, the space between
the tubes is sometimes gel-filled. Typical applications are outside
installations. One drawback of loose buffer construction is a larger
bending radius. Gel-filled cable requires the installer to spend
time cleaning and drying the individual cables, and cleaning up
the site afterwards.
Tight Buffer
Buffer layers of plastic and yarn material are applied over the
fiber. Results in a smaller cable diameter with a smaller bending
radius. Typical applications are patch cords and local area network
connections. At least one mfr. produces this type of cable for inside/outside
use.
Ribbon Cable
Typically 12 coated fibers are bonded together to form a ribbon.
There are higher density ribbons (x100) which have the advantage
of being mass-terminated into array connectors. A disadvantage is
that they are often harder, and require special tools to terminate
and splice.
Fiber Connectors
There are a lot of different types of connectors, but the ones
commonly found in LAN/MAN/WAN installations are:
FSD - Fixed Shroud Device, such as the FDDI MIC dual-fiber connector.
SC - A push-pull connector. The international standard. The SC
connectors are recommended in SP-2840A. The SC connector has the
advantage (over ST) of being duplexed into a single connector
clip with both transmit/receive fibers. SMA - Threaded connector,
not much used anymore because of losses that change with each
disconnection and reconnection.
ST - Keyed, bayonet-style connector, very commonly used.
Fiber Optic Test Equipment Continuity tester:
Used to identify a fiber, and detect a break. One type resembles
a f/o connector attached to a flashlight. Fault locator: used to
determine exact location of a break. Works by shining a very bright
visible light into the strand. At the break, this light is visible
through the cable jacket. Tone Generator and Tracer: used to identify
a cable midspan or to locate a strand at its far end. Similar in
purpose to the tone testers used on copper cable. The tone generator
imposes a steady or warbling audio tone on light passing down the
cable. The tracer detects and recovers the tone from light lost
through the cable jacket as a result of bending the cable slightly.
Optical Source and Power Meter: used to measure the end-to-end loss
through a f/o strand, or system of cable, connectors and patch cables.
Measurements are more accurate than an OTDR. Optical Time Domain
Reflectometer (OTDR): used to measure the length of a cable, and
detect any flaws in it. Can also be used to measure end-to-end loss,
although less accurately than a power meter.
Fiber Talk set
Allows using a pair of f/o strands as a telephone line.
Fiber Optic Testing, standards: see EIA-455-171 (FOTP-171), EIA
526-14.
ISDN Cable
ISDN U-loop
ISDN Basic Rate Interface (BRI) is provided by a carrier from a
central office (CO) switch to the customer premise with a two wire
U-loop RJ-45 connector on the center pins 4-5.
RJ45 Plug
=========
1 N/C
2 N/C
3 N/C
4 U-loop network connection
5 U-loop network connection
6 N/C
7 N/C
8 N/C
ISDN Network Termination (NT)
The Network Termination is a Power Supply and NT1. In North America
this functionality can be provided in the terminal equipment (i.e.
ISDN digital modem) or separate as follows
RJ45 Plug for U+PS2
===================
1 N/C
2 N/C
3 N/C
4 U-loop network connection
5 U-loop network connection
6 N/C
7 -48 VDC
8 -48 VDC Return
The ISDN cables can be silver satin patch cables (the kind that
make 10Base-T Ethernet installers cringe). The S/T bus can also
be silver satin but most installers use CAT 3 or CAT 5 with one
drop per terminal equipment. It is true that only 4-wires are needed
on the S/T bus but see below for optional power needs
ISDN S/T Bus (Point-to-Point)
One logical terminal is on the S/T bus which can be 1km long.
21.4 ISDN S/T Bus (Short Passive) Up to eight terminals on the S/T
bus which can be within 100 to 200m.
ISDN S/T Bus (Extended Passive)
Up to eight terminals on the S/T bus which can be up to 500m.
ISDN S/T Bus (NT1 Star)
Up to eight terminals on the S/T bus which are wired from a central
NT1 and can be up to 1km in length each.
ISDN S/T Bus Pinout
The S/T bus connects the NT1 with the terminal equipment.Note,
if power is not required an RJ11 (6-pin) plug could be used. Some
NT1 devices have a switch to turn off power if it is not required
by the terminal equipment. For safety reasons the power should not
be put on the S/T bus if it is not required. Typically, ISDN PC
cards do not require power from the S/T bus, but ISDN telephones
do require power from the S/T bus. Check your vendor equipment specifications
carefully.
RJ45 Plug for ISDN S/T bus
==========================
1 N/C
2 N/C
3 White/Green ..... Receive +
4 Blue ............ Transmit+
5 White/Blue ...... Transmit-
6 Green ........... Receive -
7 White/Brown ..... -48VDC (option)
8 Brown ........... -48VDC Return (option)
ISDN Cabling Guidelines
The North American ISDN Users Forum (NIUF) has produced a document
titled _ISDN Wiring and Powering Guidelines_ NIUF #433-94 which
describes residence and small business ISDN cabling. .
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