OBJ 5.2 X Flashcards
Throughput
Actual measure of how much data is successfully transferred from the source to a destination
Shielded and unshielded
Shielded Twisted Pair (STP)
▪ Wires are twisted in pairs and surrounded in a metallic shielding to
minimize EMI
▪ Outer shielding minimizes EMI, but makes STP cost more than UTP
Unshielded Twisted Pair (UTP)
▪ Number of twists determines how much EMI can be blocked
● CAT 6 has more twists per inch than CAT 5
▪ UTP is cheaper than STP
▪ Media of choice in most LANs
Plenum and riser-rated
Plenum - Used when running cables horizontally in a building across a particular
level
Riser - Used to run network cables vertically between floors in a building in a cable riser or elevator shaft
Rollover cable/console cable
A type of null-modem cable that is used to connect a computer terminal to a router’s console port
Crossover cable
A type of null-modem cable that is used to connect a computer terminal to a router’s console port
Power over Ethernet
o Passes electric power over twisted pair Ethernet cable to
powered devices
o PoE provides 15.4 to 60 watts of power using two twisted
pairs, and between 60-100 watts of power using all four
Attenuation
Reduction of signal strength between the transmission and receipt of the signal
Interference
▪ Occurs when multiple wireless networks communicate on the same
channel using the same frequency
▪ Use channels 1, 6, and 11 in the 2.4 GHz spectrum
▪ Ensure a 10-15% overlap between access points for sufficient coverage
Decibel (dB) loss
Measures the amount of signal deterioration we are experiencing on a given connection
Incorrect pinout
By default, the patch panel should use the TIA-568B pinout, with
pins 1 through 8 being connected as:
o White/Orange – Orange – White/Green – Blue – White/Blue – Green – White/Brown – Brown
Bad ports
If you suspect a bad port on a switch or router, you should connect a loopback plug to the port on that device and run a test using specialized software
Open/short
Open- There is nothing on the other end of the connection or there’s a break in the wires between the source and the destination
Short- Indicates there are two wires are connected together somewhere
in the connection
Duplexing issues
▪ When one device thinks the connection is full duplex and the other thinks it is half duplex
▪ Ensure both devices are configured to auto negotiate the connection
properly
Transmit and receive (TX/RX) reversed
Ethernet Pinout
Pins 1 to 3 (Tx+ to Rx+)
Pins 2 to 6 (Tx- to Rx-)
Cable crimper
▪ Used to attach the connector to the end of the cable
▪ support both RJ-45 and RJ-11 connectors
▪ If you are working with coaxial cables, then you will need a cable crimper that supports an RG-6 or RG-59 connector
Punchdown tool
▪ Used to terminate wires on a punch-down block without stripping off the insulation
▪ Used with 66 block or 110 block, network jacks, and patch panels
Tone generator
Allows technicians to generate a tone at one end of a connection and use the probe to audibly detect the wire pair connected to the tone
generator
Loopback adapter
Connects transmit pins (or fibers) to receive pins (or fiber) to test a network interface
Optical time-domain reflectometer (OTDR)
Used for fiber optic cables
Multimeter
▪ Checks the voltage or the amperage or the resistance of a copper cable
▪ Used to verify if a cable is broken or not
▪ Used to check coaxial cables to ensure there is no cuts or breaks in the middle of a patch cable, or test power sources or power cords
Cable tester
▪ Verifies continuity for each wire in the cable to ensure there are no breaks
▪ Verifies the pinouts of the connectors
▪ Different testers for different cable types
Wire map
▪ Like a cable tester, but it works specifically for twisted pair ethernet cables
▪ It can diagnose any issues with that cable
Tap
A simple device that connects directly to the cabling infrastructure to split or copy packets for use in analysis, security, or general network management.
Fusion splicers
A machine that is used to permanently join two fibers together
Spectrum analyzers
a device that measures and displays signal amplitude (strength) as it varies by frequency within its frequency range
(spectrum
Snips/cutters
▪ Used to simply cut a piece of cable off a larger spool or run of cable
▪ Looks a lot like a pair of scissors, but uses stronger blades to cut twisted copper cables, coaxial, cables, or even larger cable bundles
Cable stripper
Strips the end of the cable to prepare it the attachment of a RJ-45 or other type of connector
Fiber light meter
A device that provides a continuous wave of stable source of energy for attenuation measurements
