1.3 Summarize the types of cables and connectors and explain which is the appropriate type for a solution.

Question 1

Twisted pair copper cabling

Answer 1

• Balanced pair operation
  – Two wires with equal and opposite signals
  – Transmit+, Transmit- / Receive+, Receive-
• The twist keeps a single wire constantly moving away
  from the interference
  – The opposite signals are compared on the other end
• Pairs in the same cable have different twist rates

Question 2

Coaxial cables

Answer 2

• Two or more forms share a common axis
• RG-6 used in television/digital cable
  – And high-speed Internet over cable
• RG-59 used as patch cables
  – Not designed for long distances

Question 3

Twinaxial cables

Answer 3

• Two inner conductors (Twins)
• Common on 10 Gigabit Ethernet SFP+ cables
  – Full duplex, five meters, low cost, low latency compared to twisted pair

Question 4

Unshielded and shielded cable

Answer 4

• UTP (Unshielded Twisted Pair)
  – No additional shielding
  – The most common twisted pair cabling
• STP (Shielded Twisted Pair)
  – Additional shielding protects against interference
  – Shield each pair and/or the overall cable
  – Requires the cable to be grounded
• Abbreviations
  – U = Unshielded, S = Braided shielding, F = Foil shielding
• (Overall cable) / (individual pairs)TP
  – Braided shielding around the entire cable
  and foil around the pairs is S/FTP
  – Foil around the cable and no shielding around
  the pairs is F/UTP

Question 5

Structured cabling standards: International ISO/IEC 11801

Answer 5

cabling standards
– Defines classes of networking standards

Question 6

Structured cabling standards: Telecommunications Industry Association (TIA)

Answer 6

– Standards, market analysis, trade shows,
government affairs, etc.
– ANSI/TIA-568:
Commercial Building Telecommunications
Cabling Standard
* Commonly referenced for pin and
pair assignments of eight-conductor
100-ohm balanced twisted pair cabling
– T568A and T568B

Question 7

T568A and T568B termination

Answer 7

• Pin assignments in EIA/TIA-568-B - Eight conductor 100-ohm balanced twisted-pair cabling
• 568A and 568B are different pin assignments for 8P8C connectors
  – Specification assigns the 568A pin-out to horizontal cabling - Many organizations have traditionally used 568B
• You can’t terminate one side of the cable with 568A and the other with 568B
  – You’ll run into confusion and technical problems

Question 8

Fiber communication

Answer 8

• Transmission by light
  – The visible spectrum
• No RF signal
  – Very difficult to monitor or tap
• Signal slow to degrade
  – Transmission over long distances
• Immune to radio interference
  – There’s no RF

Question 9

UPC vs. APC

Answer 9

• Controlling light-Laws of physics apply
• Return loss-Light reflected back to the source
• UPC (Ultra-polished connectors)
  – Ferrule end-face radius polished at a zero degree angle
  – High return loss
• APC (Angle-polished connectors)
  – Ferrule end-face radius polished at an eight degree angle
  – Lower return loss, generally higher insertion loss than UPC

Question 10

Media Converter

Answer 10

• OSI Layer 1
  – Physical layer signal conversion
• Extend a copper wire over a long distance
  – Convert it to fiber, and back again
• You have fiber
  – The switch only has copper ports
• Almost always powered
  – Especially fiber to copper

Question 11

Transceiver

Answer 11

• Transmitter and receiver
  – Usually in a single component
• Provides a modular interface
  – Add the transceiver
  that matches your network

Question 12

SFP and SFP+

Answer 12

• Small Form-factor Pluggable (SFP)
  – Commonly used to provide 1 Gbit/s fiber
  – 1 Gbit/s RJ45 SFPs also available
• Enhanced Small Form-factor Pluggable (SFP+)
  – Exactly the same size as SFPs
  – Supports data rates up to 16 Gbit/s
  Common with 10 Gigabit Ethernet

Question 13

QSFP

Answer 13

• Quad Small Form-factor Pluggable
  – 4-channel SFP = Four 1 Gbit/s = 4 Gbit/s
  – QSFP+ is four-channel SFP+ =
  Four 10 Gbit/sec = 40 Gbit/sec
• Combine four SFPs into a single transceiver
  – Cost savings in fiber and equipment
• Bi-Directional (BiDi) QSFP and QSFP+
• Additional efficiency over a single fiber run

Question 14

Duplex communication

Answer 14

• Two fibers
  – Transmit and receive

Question 15

Bi-Directional (BiDi) transceivers

Answer 15

• Traffic in both directions with a single fiber
  – Use two different wavelengths
• Reduce the number of fiber runs by half

Question 16

Copper patch panel

Answer 16

• Punch-down block on one side, RJ45 connector on the other
• Move a connection around - Different switch interfaces
• The run to the desk doesn’t move

Question 17

66 block

Answer 17

• A patch panel for analog voice
  – And some digital links
• Left side is patched to the right
  – Easy to follow the path
• Wire and a punch-down tool
  – No additional connectors required
• Generally replaced by 110 blocks
  – Still seen in many installations

Question 18

Fiber distribution panel

Answer 18

• Permanent fiber installation - Patch panel at both ends
• Fiber bend radius - Breaks when bent too tightly
• Often includes a service loop
  – Extra fiber for future changes

Question 19

110 block

Answer 19

• Wire-to-wire patch panel
  – No intermediate interface required
• Replaces the 66 block
  – Patch Category 5 and Category 6 cables
• Wires are “punched” into the block
  – Connecting block is on top
• Additional wires punched into connecting block
  – Patch the top to the bottom

Question 20

Krone block

Answer 20

• An alternative to the 110 block
  – Common in Europe
• Options available for many purposes
  – Analog and digital communication
  – Different models can support
  higher frequencies

Question 21

BIX (Building Industry Cross-connect)

Answer 21

• Created in the 1970s by Northern Telecom
  – A common block type
• Updated through the years
  – GigaBIX performance is better than the
  Category 6 cable standard

Question 22

Eathernet Standards: Ethernet

Answer 22

• The most popular networking technology in the world
  – Standard, common, nearly universal
• Many different types of Ethernet
  – Speeds, cabling, connectors, equipment
• Modern Ethernet uses twisted pair copper or fiber
• BASE (baseband)
  – Single frequency using the entire medium
  – Broadband uses many frequencies, sharing the medium

Question 23

10 and 100 megabit Ethernet

Answer 23

• 10BASE-T (twisted pair)
  – Two pair, Category 3 cable minimum
  – 100 meter maximum distance
• 100BASE-TX
  – “Fast Ethernet”
  – Category 5 or better twisted pair copper - two pair
  – 100 meters maximum length

Question 24

1000BASE-T

Answer 24

• Gigabit Ethernet over Category 5
  – 4-pair balanced twisted-pair
• Category 5
  – Category 5 is deprecated, so we use Cat 5e today
  – A shift to using all four pair
  – 100 meter maximum distance

Question 25

10GBASE-T

Answer 25

• 10 Gig Ethernet over copper
  – 4-pair balanced twisted-pair
• Frequency use of 500 MHz
  – Well above the 125 MHz for gigabit Ethernet
• Category 6
  – Unshielded: 55 meters, Shielded: 100 meters
• Category 6A (augmented)
  – Unshielded or shielded: 100 meters

Question 26

40GBASE-T

Answer 26

• 40 gigabit per second Ethernet
  – 4-pair balanced twisted-pair
• Category 8 cable - Up to 30 meters

Question 27

100 megabit Ethernet over fiber

Answer 27

• 100BASE-FX
  – Pair of multimode fiber - Same fiber as FDDI
  – Laser components
  – 400 meters (half-duplex), 2 kilometers (full-duplex)
• 100BASE-SX
  – A less-expensive version of
  100 megabit Ethernet over fiber
  – LED optics, 300 meters maximum distance

Question 28

Gigabit Ethernet over fiber

Answer 28

• 1000BASE-SX
  – Gigabit Ethernet using NIR (near infrared) light
  – Usually over multi-mode fiber
  – 220 meters to 500 meters,
  depending on fiber type
• 1000BASE-LX
  – Gigabit Ethernet using long wavelength laser
  – Multi-mode fiber to 550 meters
  – Single-mode fiber to 5 kilometers

Question 29

10 Gigabit Ethernet over fiber

Answer 29

• 10GBASE-SR – Short Range
  – Multimode fiber
  – 26 to 400 meters, depending on the fiber
• 10GBASE-LR – Long range
  – Single-mode fiber
  – 10 kilometers maximum range

Question 30

WDM

Answer 30

• Wavelength-Division Multiplexing
  – Bidirectional communication over a single strand of fiber
• Use different wavelengths for each carrier
  – Different “colors”
• CWDM (Coarse Wavelength-Division Multiplexing)
  – 10GBASE-LX4 uses four 3.125 Gbit/sec carriers
  at four different wavelengths
• DWDM (Dense Wavelength-Division Multiplexing)
  – Multiplex multiple OC carriers into a single fiber
  Add 160 signals, increase to 1.6 Tbit/s