Module 4 Flashcards
Devices on a wireless network must be connected to a……
wireless access point (AP) or wireless router
3 components of an access point:
The wireless antennas
Several Ethernet switchports
An internet port
Ethernet NICs are used for a…
wired connection
wireless local area network (WLAN) NICs are used for
wireless connections
Provides the means to transport the bits that make up a data link layer frame across the network media.
The OSI Physical Layer
The physical layer encodes the frames and creates the _____, _______. or _______ signals that represent the bits in each frame.
electrical
optical
radio wave
The ____________ retrieves these individual signals from the media, restores them to their bit representations, and passes the bits up to the data link layer as a complete frame.
Destination node physical layer
True or false? The physical layer is only concerned with wired network connections.
False
True or false? When a frame is encoded by the physical layer, all bits are sent over the media at the same time.
False
The physical layer of the receiving device passes bits up to what higher level layer?
Data Link Layer
PDU acronym?
Define.
Protocol Data Unit.
A specific block of information transferred over a network.
What PDU is received by the physical layer for encoding and transmission?
Frame.
ISO acronym.
International Organization for Standardization
TIA/EIA acronym.
Telecommunications Industry Association/Electronic Industries Association
ITU acronym.
International Telecommunication Union
ANSI acronym.
American National Standards Institute
IEEE acronym.
Institute of Electrical and Electronics Engineers
FCC acronym.
Federal Communication Commission
ETSI acronym.
European Telecommunications Standards Institute
The TCP/IP standards are implemented in software and governed by the……..
IETF (Internet Engineering Task Force)
IETF acronym.
Internet Engineering Task Force.
The physical layer standards are implemented in hardware and are governed by many organizations including… (5)
ISO EIA/TIA ITU-T ANSI IEEE
The physical layer standards address three functional areas:
Physical Components.
Encoding.
Signaling.
A method of converting a stream of data bits into a predefined “code”
Encoding or Line Encoding.
Groupings of bits used to provide a predictable pattern that can be recognized by both the sender and the receiver.
Codes
The way that bits are represented is called the….
Signaling Method.
Data transfer is usually discussed in terms of…
Bandwidth.
The capacity at which a medium can carry data.
Bandwidth.
Measures the amount of data that can flow from one place to another in a given amount of time.
Digital Bandwidth.
Two factors that determine the practical bandwidth of a network:
The properties of the physical media.
The technologies chosen for signaling and detecting network signals.
The fundamental unit of bandwidth.
bps (Bits per second)
Three terms used to measure the quality of bandwidth…
Latency.
Throughput.
Goodput.
The 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.
Three factors that influence throughput:
The amount of traffic.
The type of traffic.
The latency created by the number of network devices encountered between source and destination.
The measure of usable data transferred over a given period of time.
Goodput.
Throughput minus traffic overhead for establishing sessions, acknowledgments, encapsulation, and re-transmitted bits.
Goodput.
_______ is always lower than throughput, which is generally lower than the bandwidth.
Goodput.
Which media uses patterns of microwaves to represent bits?
Wireless.
Which media uses patterns of light to represent bits?
Fiber-Optic.
Which media uses electrical pulses to represent bits?
Copper.
Which of these is the name for the capacity of a medium to carry data?
Bandwidth.
Which of these is a measure of the transfer of bits across the media?
Throughput.
Signals that can distort and corrupt the data signals being carried by copper media.
Electromagnetic Interference (EMI).
Radio Frequency Interference (RFI).
A disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an adjacent wire.
Crosstalk.
To counter the negative effects of EMI and RFI, some types of copper cables are wrapped in __________ and require proper grounding connections.
Metallic Shielding.
The susceptibility of copper cables to electronic noise can also be limited using these recommendations… (3)
Selecting the cable type or category most suited to a given networking environment.
Designing a cable infrastructure to avoid known and potential sources of interference in the building structure.
Using cabling techniques that include the proper handling and termination of the cables.
Three main types of copper media used in networking…
Unshielded Twisted-Paid (UTP) cable.
Shielded Twisted-Pair (STP) Cable.
Coaxial Cable.
The most common networking media.
Unshielded twisted-pair (UTP)
3 key characteristics of UTP cable.
The outer jacket protects the copper wires from physical damage.
Twisted-pairs protect the signal from interference.
Color-coded plastic insulation electrically isolates wires from each other and identifies each pair.
Cables that combine the techniques of shielding to counter EMI and RFI, and wire twisting to counter crosstalk.
STP. Shielded Twisted-Pair.
This cable is used in Wireless installations and Cable internet installations.
Coaxial Cable.
Cable that has two conductors that share the same axis.
Coaxial Cable.
4 key features of coaxial cable…
Outer jacket.
Braided copper shielding.
Plastic insulation.
Copper conductor.
Which attaches antennas to wireless devices? It can also be bundled with fiber-optic cabling for two-way data transmission.
coaxial.
Which counters EMI and RFI by using shielding techniques and special connectors?
STP
Which of the following is the most common network media?
UTP
Which of the following terminates with BNC, N type and F type connectors?
Coaxial
What is it called when two wires are placed close together, and their magnetic fields are the exact opposite of each other?
Cancellation
The most common type of networking cable. It is commonly used to interconnect a host to a switch and a switch to a router.
Ethernet Straight-through.
A cable used to interconnect similar devices.
Ethernet Crossover.
Connects a workstation serial port to a router console port, using an adapter.
Rollover
Which fiber-optic cable types can help data travel approximately 500 meters?
multimode
Which fiber-optic cable types use light emitting diodes (LEDs) as a data light source transmitter?
multimode
Which fiber-optic cable types use lasers in a single stream as a data light source transmitter?
single-mode
Which fiber-optic cable types is used to connect long-distance telephony and cable TV applications?
single-mode
Which fiber-optic cable types can travel approximately 100 km?
single-mode
Which fiber-optic cable types is used within a campus network?
multimode
Fiber-optic cables are broadly classified into two types:
Single-mode fiber (SMF)
Multimode fiber (MMF)
Cable that transmits data over longer distances and at higher bandwidths than any other networking media.
Optical Fiber.
Fiber optic cable that consists of a very small core and uses expensive laser technology to send a single ray of light
Single-Mode Fiber (SMF)
Fiber optic cable that consists of a larger core and uses LED emitters to send light pulses.
Multimode Fiber (MMF)
These concentrate the wireless signals from users and connect to the existing copper-based network infrastructure, such as Ethernet.
Wireless Access Point (AP)
These provide wireless communication capability to network hosts.
Wireless NIC adapters.
True or false. Wireless is not well suited for enterprise networks.
False.
True or false. Wireless LANs operate in full-duplex allowing all devices to send or receive data at the same time so the number of users does not impact performance.
False.
Which wireless standards is best suited for industrial and IoT environments?
Zigbee
Which wireless standards is used for Personal Area Networks (PANs) and allows devices to communicate over distances of 1 to 100 meters?
Bluetooth.
A network administrator is troubleshooting connectivity issues on a server. Using a tester, the administrator notices that the signals generated by the server NIC are distorted and not usable. In which layer of the OSI model is the error categorized?
Physical Layer.
What type of cable is used to connect a workstation serial port to a Cisco router console port?
rollover.
Why are two strands of fiber used for a single fiber optic connection?
They allow for full-duplex connectivity.
Which procedure is used to reduce the effect of crosstalk in copper cables?
Twisting opposing circuit wire pairs together.
What is one advantage of using fiber optic cabling rather than copper cabling?
It is able to carry signals much farther than copper cabling.
Connection recommended if the end-user device needs mobility when connecting to the network.
Wireless Connection.
Which type of UTP cable is used to connect a PC to a switch port?
straight-through
What is the definition of bandwidth?
The amount of data that can flow from one place to another in a given amount of time.
What converts bits into a predefined code in order to provide a predictable pattern to help distinguish data bits from control bits.
Frame Encoding.
Cancellation is a characteristic of which type of what?
UTP cabling.
What is the purpose of the OSI physical layer?
Transmitting bits across the local media.
The distortion of the transmitted messages from signals carried in adjacent wires describes what?
Crosstalk.
The measure of the bits transferred across the media over a given period of time describe what?
Throughput.
Which standards organization oversees development of wireless LAN standards?
IEEE
