Week 1 The Physical Layer Flashcards
The most common type of cabling used for connecting computing devices is known as what & why is it called that? & what do they do?
The most common type of cabling used for connecting computing devices is known as twisted pair.
It’s called a twisted pair cable because it features pairs of copper wires that are twisted together.
These pairs act as a single conduit for information, and their twisted nature helps protect against electromagnetic interference and crosstalk from neighboring pairs.
What is the concept that information can flow in both directions across the cable.
Duplex communication is the concept that information can flow in both directions across the cable.
What kind of communication is a phone call considered?
A phone call is considered as “duplex communication” since both parties can listen and speak.
The way networking cables ensure that duplex communication is possible is by what?
by reserving one or two pairs for communicating in one direction.
They then use the other one or two pairs for communicating in the other direction.
What is it known as when devices on either side of a networking link can both communicate with each other at the exact same time?
full duplex is known as when devices on either side of a networking link can both communicate with each other at the exact same time.
What does Half-duplex mean?
it means while communication is possible in each direction, only one device can be communicating at a time.
What are the communications protocols that determine how much data can be sent over a twisted pair cable, how quickly that data can be sent, and how long a network cable can be before the data quality begins to degrade.?
“Ethernet over twisted pair technologies” are the communications protocols that determine how much data can be sent over a twisted pair cable, how quickly that data can be sent, and how long a network cable can be before the data quality begins to degrade.
it doesn’t matter whether you’re streaming your favorite song, emailing your boss, or using an ATM, what you’re really doing is what?
what you’re really doing is sending ones and zeros across the physical layer of the many different networks between you and the server you’re interacting with.
A standard copper network cable, once connected to devices on both ends, will carry a what?
it will carry a constant electrical charge.
Ones and zeros are sent across those network cables through a process called what?
through a process called modulation
what is a way of varying the voltage of the charge moving across the cable?
modulation
When used for computer networks, this kind of modulation is more specifically known as what?
line-coding
line-coding allows devices on either end of a link to do what?
to understand that an electrical charge in a certain state is a zero, and in another state is a one.
What is Ethernet over twisted pair technologies?
it is the communications protocols that determine how much data can be sent over a twisted pair cable, how quickly that data can be sent, and how long a network cable can be before the data quality begins to degrade.
