Transcript Lesson 10 - rbvweb.net

BTT 101 / 2O1
Lesson 10
Dundas Valley Secondary
Mr. Young
To connect to the Internet from home you need
WAN
Link
Ethernet
Cable
A Computer
A Modem
PC
Laptop
iPhone
etc
DSL
Cable
An ISP
An Internet Service Provider is a company that
offers its customers access to the Internet
through their own LAN.
Customers connect to the ISP through a modem
such as DSL, dial-up or cable .
A Modem is a device that converts (modulate and
demodulate) the Ethernet signal from your
computer into the DSL or cable signal.
The Wired Network
Ethernet is a technology for wired networks.
Plug a Patch cable (or Ethernet cable) into the
Ethernet NIC (Network Interface Card) on your
computer and into the modem
Network
Card
Ethernet
Cable
In networking, a protocol is a set of rules that
govern communication.
Ethernet is a protocol that defines the cabling
and how the signals are sent.
Gigabit Ethernet is the newest version with a
bandwidth of about 1 Gbps.
A patch cable plugs into
an RJ45 plug on the
network card
If you have more than one computer that needs
to be connected to the Internet, then you need
a network device called a router.
The router plugs
into a modem,
which links
to the ISP
Each computer
connects to
the router
with a patch
cable
A router is a network device that forwards
packets from one network (LAN) to another
using IP addresses.
A LAN or Local Area Network is a type of
computer network covering a small physical
area, like a home, office, or small group of
buildings, such as a school.
Ethernet and WiFi are two common
technologies for connecting computers in a LAN.
The computers
in each LAN
plug into a
network switch.
The switch
concentrates
network
connections.
Three LANs connected to a router
and then to the Internet
This means that
it brings network
cables together at a
central point.
Home networks also use wireless technology
or WiFi
The wireless version of Ethernet. WiFi stands for
“Wireless Fidelity” imitating Hi-Fi for “high
fidelity" audio.
The official standard is called IEEE 802.11 with
improvements marked by letters
802.11g is called Wireless-G
802.11n is called Wireless-N
In your home network, you can have both
wired (Ethernet ) and wireless (WiFi) devices
Most desktop computers have an
Ethernet card (NIC)
Most laptops and netbooks have a wireless
network card (and some also have Ethernet)
One type of wireless network card
looks like a USB flash drive
but it just connects the computer
to a wireless network.
Some routers have both Ethernet and WiFi
WiFi
antennae
WAN
port
A Linksys
wireless router
4-port
switch
Information like email and Webpages travel
through your home network (a LAN) and over
the Internet in packets.
A packet is like an electronic envelope that
contains your data.
Packets that are sent over the
Internet are usually
about 1500 bytes .
It takes many packets to send the
average message.
The packet contains the IP Address of both the
destination and the source (the “mailing
address” and the “return address” on a letter).
Source Address 
your address
Destination Address 
where it is going
An Internet Protocol or IP Address is the
address of a computer on a network.
It is a 32-bit binary number.
It is written in decimal numbers to make it easy
to read and write.
It has 4 numbers between 0 and 255 separated
by dots.
For example: 192.168.1.202
Binary:
11000000101010000000000111001010
Every computer on a TCP/IP network must have
an IP address
TCP/IP is the name for the suite (group) of
protocols that govern the Internet
HTTP is one protocol in the TCP/IP suite
HTTP is a protocol that governs Webpages
Many computers get an IP address
automatically from a DHCP server
At home your router “serves” IP addresses to
computers on the LAN
Dynamic Host Configuration Protocol
A networking protocol used by computers on a
network to get an IP Address.
The computer (a DHCP host) sends a request
over the LAN for an IP Address.
A DHCP server (a router or server) assigns a
temporary and unique IP Address to the host.
This is called a Dynamic IP Address.
If the user configures the IP Address
themselves, this is called a Static IP Address.
When several LANs are linked together
this is called a Wide Area Network or WAN
The Internet is a planet wide WAN.
The network backbone is the part of a
network that connects the core points in a
WAN.
It usually has the highest-speed
transmission paths in the network and may
also run the longest distances.
Smaller networks are attached to the
backbone.
Bandwidth is the amount of data sent
over a communication line,
like a network cable.
It is measured in bits per second or bps.
A signal sent over an
Ethernet cable, for
example, has a bandwidth
of 100 Mbps
(megabits per second).
Gigabit Ethernet is 1000
Mbps or 1 Gbps
Bandwidth is easier to understand if you
compare it to water flowing through pipes.
With a bigger pipe more water can
flow per minute.
In electronic communication,
the wires are not bigger
but use different technology
to send data faster
across different
data “pipelines” or
With a bigger “pipeline”
more data can flow
channels.