Progression: Field Tech IV - V
Baseband signaling - -is predominant in Ethernet networks.
two ways we can use a flow of energy to carry data - -Analog and digital
Simplex - -A signal may flow in only one direction. A commercial radio station uses
simplex communication, because listeners cannot transmit radio signals back to the
station.
Half-duplex - -Signals may flow in either direction, but not simultaneously. For
example, a two-way radio allows only one user to speak at any one time.
Full-duplex - -Signals may flow in both directions simultaneously. A telephone is the
best example of full-duplex communication. One wire brings a signal from the telephone
company to your home, and a second wire carries a separate signal from your home back
to the telephone company. Thus, you can both hear and speak simultaneously.
Synchronous - -The communicating parties or endpoints use time to organize
communication. In a data network, two communicating computers use each clock "tick" to
detect whether a digital bit is a 1 or 0. For example, as each time interval passes, a
computer checks the network cable to see whether the voltage is high (binary 1) or low
(binary 0). Because the timing determines the meaning of the signal, it is essential that the
endpoints are synchronized to the same clock before sending signals.
Asynchronous - -Bits are not transmitted on any strict timetable. For example, a
computer modem typically uses 8 bits to represent one character or letter. To indicate the
start of each character, the sending modem transmits a "start" bit to alert the receiving end
to the incoming signal. After the final bit of the eighth character is transmitted, the sending
modem transmits a "stop" bit to indicate the end of the character. This process is repeated
for each character the modem transmits. Thus, the receiving modem must stay
synchronized to the signal only for the length of time it takes to transmit 8 bits. If the
sending and receiving clocks are slightly out of synchronization, these short data transfers
will still be successful.
Which of the following is most typical of a broadband network? - -Multiple analog
channels
Data bus size - -The size of the bus refers to the number of data bits a CPU can work
on in a single instruction.
Clock speed - -The clock speed indicates how many instructions per second the
processor can execute. Each "tick" of the clock is called a cycle, thus clock speed is
measured in cycles per second. A single cycle per second is called 1 hertz (Hz), 1,000 Hz is
1 kilohertz (kHz), 1 million Hz is 1 megahertz (MHz), and 1 billion Hz is 1 gigahertz (GHz). A
CPU that runs at 400,000,000 cycles per second is a 400- MHz processor.
, Progression: Field Tech IV - V
storage - -used to describe media that hold data for longer periods, even when the
power goes off.
What components are common to all computer systems? (Check all that apply.) - -
Processor
Memory
Storage
I/O
What does I/O stand for? - -Input / Output
A NIC is a device used for: - -Signaling
A sound card is what general type of computer component? - -Input/output
Distributed applications - -Applications can be distributed on the network based on
their requirements for resources. For example, an application that provides computing-
intensive services can be installed on a computer with very high processing capacity, while
the user's client application runs on a workstation that provides high-end graphic display
capabilities.
Resource sharing - -A server process typically can serve many clients, thus
client/server architecture is a good way to share many types of resources across an
organization.
Applications - -software programs used to perform work
Peer-to-peer networking software - -is included with most popular desktop OSs.
Each individual user configures software settings to allow or disallow the sharing of that
computer's resources by other users. There is no central authority that decides what users
may have access to what resources.
A network OS (NOS) - -also called a client/server OS, provides centralized control of
all network resources. A network administrator can decide what each user may see and do
on the network. By far, the most common NOS packages are Microsoft and UNIX/Linux
servers.
Which of the following is managed by the OS? - -Keyboard input
Screen display
File I/O
Peripheral control
, Progression: Field Tech IV - V
The primary purpose of a device driver is to control hardware under the supervision of the
OS. True or False? - -True
Most LANs - -use star bus topologies.
Personal Area Networks (PAN) - -are small and local. PANs connect by means of
Bluetooth wireless and can connect phones, tablets, mice, keyboards, and more.
Local Area Networks (LAN) - -can range from a few nodes in a home office, to several
hundred nodes in a corporation. However, a LAN is typically confined to a single building.
Campus Area networks (CAN) - -consist of LANs connected across multiple
buildings, using transmission links owned by the company that owns the network.
Metropolitan Area Networks (MAN) - -are formed by connecting LANs in several
locations across a city or small region. The links between LANs are typically leased from
companies that provide telephony and data services.
Wide Area Networks (WAN) - -are essentially the same as MANs, but span longer
distances. A WAN may include sites in the same country or multiple countries.
Global Area Networks (GAN) - -are designed to allow users to have unlimited
uninterrupted network access anywhere around the globe via LAN, wireless, cellular, and
satellite connections.
Which of the following network topologies forms a closed loop? - -Ring topology
Which of the following network topologies connects devices to a shared straight-line
cable? - -Bus topology
Twisted pair - -is the most common type of copper cable used in networks.
There are two major ways to limit noise and crosstalk in a cable design: - -Shielding
Cancellation
Coaxial Ethernet networks must obey the "5/4/3 rule:" - -Up to five segments can be
connected in a series between transmitter and receiver.
Up to four signal-repeating devices (repeaters, hubs, bridges, or switches) may be used to
connect segments.
A maximum of only three segments can contain Ethernet nodes.
Coaxial Cabling Characteristics Bandwidth - -Broadband coaxial systems, such as
Internet access via cable modems, offer high bandwidth because a single cable can carry
multiple baseband channels.
