Transcript ITS_7_Intro to Networking

Introduction To
Networking
Requirements for Internet connection
Connections can be seen as 2 components:
The physical connection: transfers signals
between a PC and a remote device on the
Internet by connecting an expansion card such
as a modem or a NIC from a PC to a network,
most often via an Ethernet cable.
The logical connection: uses protocols. A
protocol is a formal description of a set of rules
and conventions that govern how components
on a network communicate. Ex: TCP/IP
A network card (NIC) is an expansion card that is
inserted into a computer to allow it to connect to the
network. It can also be an integrated component
The NIC communicates with the network through a
serial connection and within the computer through
parallel connections.
You may need to install a NIC when:
•adding a NIC to a PC that does not already have
one.
•replacing a bad or damaged NIC.
•when upgrading from a 10 Mb to a 10/100 Mb or
even a Gigabit NIC.
NIC or Lan Adapter
You will select a NIC based on:
 Type of protocol (Ethernet, Token Ring, or FDDI)
your network is running;
 Type of Media (UTP, Coax, Fiber) your network
is wired with;
 Type of System Bus (PCI, PCI Express, USB)
used in your PC.
High-speed and dial-up connectivity
• In the 1970s, modems provided connectivity for
dumb terminals to a centrally based computer
• The connection rate was very slow, about 30
characters/second.
• In the 1980s, the transfer of large files and
graphics became desirable.
• In the 1990s modems were running at 9600 bps
and reached the current standard of 56 kbps by
1998.
• By 2000, high speed services moved from the
corporate environment to the consumer market,
and DSL and cable modems are "always on" high
speed services that provide near instant access.
TCP/IP description and configuration
TCP/IP is a set of protocols or rules developed
to allow cooperating computers to share
resources across a network.
To enable TCP/IP on the workstation, it must be
configured using the operating system tools
Testing connectivity with ping
Ping is a utility used to verify Internet connectivity.
Ping works by sending multiple IP packets to a
specified destination. Each packet sent is a
request for a reply.
Ping 127.0.0.1 : verifies the operation of the TCP/IP
stack and transmit/receive function within the
NIC, and never enter the network. We call this a
loopback.
Testing connectivity with ping
• If you ping the IP address of host computer, you
verify the TCP/IP address configuration for the
local host and connectivity to the host.
• Pinging the default-gateway IP address ensures
you can reach the router port, which is the edge of
your LAN network, and the gateway to the rest of
the network beyond your LAN.
• Pinging the remote destination IP address sends
the ICMP ping packets through the network to the
distant end, verifying a complete network
connectivity.
Web browser and plug-ins
A Web browser acts on behalf of a user by:
– contacting a Web server
– requesting information
– receiving information
– displaying the results on a screen
The first popular browser was Netscape Navigator
Web Browsers include:
 Google Chrome
 Internet Explorer
 Mozilla Firefox
 Opera
 Safari
Web Browsers - interpret hypertext markup
language (HTML) – the language used to code
Web page content.
Hyperlinks - computer program commands that
point to other places
Plug-ins - application programs that run
proprietary files that Web browsers are unable to
interpret:
Flash - plays multimedia files
Quicktime – plays video files, which was created
by Apple
Real Player – plays audio files
and other possible web applications.