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
