Module 4 Physical Layer Flashcards
Before any network communications can occur, a _____ to a local network must be established
Physical Connection
The connection could be ___ or ____, depending on the setup of the network
Wired or wireless
A ______ connects a device to the network.
Network Interface Card (NIC)
What are the layers of the OSI model
- Physical
- Data LInk
- Network
- Transport
- Session
- Presentation
- Application
_____ converts the stream of
bits into a format recognizable by
the next device in the network
path
Encoding
_____ method is how the bit
values, “1” and “0” are represented on
the physical medium
Signaling
_____ is the capacity at which a medium can carry data.
Bandwidth
What is the meaning of tbps
Terabits per second
_____ measures the amount of data that can flow from one place to
another in a given amount of time; how many bits can be transmitted in a second.
Digital Bandwidth
Amount of time, including delays, for data to travel from one given point to another
Latency
The measure of the transfer of bits across the media over a given period of time
Throughput
The measure of usable data transferred over a given period of time
Goodput
____ is the most common type of cabling used in networks today. It i
Copper Cabling
the longer the electrical signals have to travel, the weaker they get.
Attenuation
_____ is susceptible to interference from two sources, which can distort and
corrupt the data signals (Electromagnetic Interference (EMI) and Radio Frequency Interference
(RFI) and Crosstalk)
Electrical Signal
____ is the most common networking
media.
UTP
- Terminated with RJ-45 connectors
- Interconnects hosts with intermediary
network devices.
UTP
UTP has _____ of color-coded copper wires
twisted together and encased in a flexible plastic
sheath.
Four Pairs
Each wire in a pair of wires uses
opposite polarity. One wire is negative, the other
wire is positive. They are twisted together and the
magnetic fields effectively cancel each other
and outside EMI/RFI.
Cancellation
What is the color combination to make T568A
White Green, Green, White Orange, Blue, White Blue, Orange, White Brown, Brown
What is the color combination to make T568B
White Orange, Orange, White Green, Blue, White Blue, Green, White Brown, Brown
- Better noise protection than UTP
Shielded Twisted Pair (STP) - More expensive than UTP
- Harder to install than UTP
- Terminated with RJ-45 connectors
- Interconnects hosts with intermediary
network devices
Shielded Twisted Pair
What are the common use of Coaxial Cable
- Wireless Installations
- Cable Internet Installations
Transmits data over longer distances at higher bandwidth than any other
networking media
Fiber Optic Cable
Made of flexible, extremely thin strands of very pure glass
Fiber Optic Cable
- Very small core
- Uses expensive lasers
- Long-distance applications
Single Mode Fiber
- Larger core
- Uses less expensive LEDs
- LEDs transmit at different angles
- Up to 10 Gbps over 550 meters
Multimode Fiber
____ refers to the spreading out of a light pulse over time. Increased dispersion means
increased loss of signal strength.
Dispersion
Used for backbone cabling applications and interconnecting
infrastructure devices
Enterprise Network
Used to provide always-on broadband services to homes
and small businesses
Fiber to Home (FTTH)
Used by service providers to connect countries and cities
Long-Haul Networks
Used to provide reliable high-speed, high-capacity
solutions capable of surviving in harsh undersea environments at up to transoceanic
distances
Submarine Cable Networks
_____ is primarily used as backbone cabling for high-traffic, point-to-point
connections between data distribution facilities and for the interconnection of buildings
in multi-building campuses.
Optical Fiber
What are some limitation of wireless media
- Coverage Area
- Interference
- Security
- Shared Medium
Effective coverage can be significantly impacted by the physical
characteristics of the deployment location.
Coverage Area
Wireless is susceptible to interference and can be disrupted by many
common devices.
Interference
Wireless communication coverage requires no access to a physical strand
of media, so anyone can gain access to the transmission.
Security
WLANs operate in half-duplex, which means only one device can
send or receive at a time. Many users accessing the WLAN simultaneously results in
reduced bandwidth for each user
Shared Medium
Wireless LAN (WLAN) technology
Wi-Fi
Wireless Personal Area network (WPAN) standard
Bluetooth
Uses a point-to-multipoint topology to provide broadband wireless
access
WiMAX
Low data-rate, low power-consumption communications, primarily
for Internet of Things (IoT) applications
Zigbee
Concentrate wireless signals from users and connect to the existing copper-based network infrastructure
Wireless Access Point (AP)
Provide wireless communications capability to
network hosts
Wireless NIC Adapters
