Physical media
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Coaxial
Twisted pair
Fiber optic
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Coaxial Cable
2
Coaxial Cable Types - Bus
Application
Thickness
Connector
Type
RG-8
RG-58
Thick Ethernet
(500 meters)
10Base-5
0.405 inch
Thin Ethernet
(185 meters)
10Base-2
0.195 inch
N
BNC with a
T-fitting
3
Other
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Plenum – space between floors
Plenum type cable – demanded by the National Fire
Protection Association that cables run within the
plenum have been tested and guaranteed as save,
that is, thye must be
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Fire retardant and create little or no smoke and poisonous
gas when burned
RG-59 for TV, RG-6 for TV and cable modems
RG-62 for ARCnet - obsolete
4
Twisted-Pair Cable
5
UTP Cable Grades
EIA/TIA Grade
Applications
Cat2
For voice, obsolete
Category 3 (16 MHz)
Voice-grade telephone networks, 10-Mbps
Ethernet, 4-Mbps Token Ring, 100Base-T4
Fast Ethernet, and 100Base-VG-AnyLAN
Category 4 (20 MHz)
16-Mbps Token Ring
Category 5
100Base-TX Fast Ethernet, Synchronous
Optical Network (SONET), and Optical Carrier
(OC3) Asynchronous Transfer Mode (ATM)
Category 5e and 6
1000Base-T (Gigabit Ethernet)
Category 6 (250 MHz)
Become standard in 2002, backbone
6
Connect s
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RJ-11 for phone and DSL (Digital Subscriber
Link)
RJ-45 for LAN, use a crimper to connect the
wires to the connect first
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Fiber Optic Cable
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The Cores
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Can be glass for greater distance, or
Plastic to reduce cost
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Single Mode vs. Multimode Fiber
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Single mode, single-mode optical fiber (SMF) is an
optical fiber designed to carry only a single ray of
light (mode)
Multimode fiber optic cable has a large diametral
core that allows multiple modes of light to
propagate
http://en.wikipedia.org/wiki/Multi-mode_optical_fiber
http://www.multicominc.com/active/manufacturer/multicom
/Fiber%20Optics/singlemode-multimode.html
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Multimode Fiber
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Fiber Optic Cable Types
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Singlemode (SMF): Used for wide area networks
(WANs) and other long cable runs, glass core, light
source is transmitted from end to end and pulsed
to communicate, can go up to 40 km
Multimode (MMF): Used for local area networks
(LANs) and short cable runs, light is reflected by
cladding, core can be either glass or plastic, 1/50
the speed of SMF, 3000 ft distance
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Pros and Cons of fiber
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Fiber Optic Connectors (SC, ST)
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Fiber Optic Connectors – ST and SC
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See page 64 (N10 – 00 5 edition) for
examples of ST and SC connectors
Fiber cables always need a pair – one for
each direction (sending and receiving)
Figure 3.8 a MT-RJ
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Serial Cables
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RS-232
USB (Universal Serial Bus) can connect up to
127 devices
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Properties of cables
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Transmission speed – unit Mbps
Distance UTP – 100 meters
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Attenuation – the degradation of signal due to
medium “burns” energy
Duplex
Noise Immunity
Frequency
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Cat 5e can go 1Gbps for short distance
Cat 6, build for 1Gbps
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Wiring Standards
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568A straight –through cable
568B Crossover cable
Rolled cable
Hardware loopback
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568A straight –through cable
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568B Crossover cable
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Rollover – mostly CISCO
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Loopback
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Wiring Distributions
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Vertical
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Between floors
Horizontal
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Within the same floor
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Patch Panels -- inactive
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Demarc
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Demarcation – last point of responsibility
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