2. What is Network
• When two or more computers are connected with
each other in such a way so that they can exchange
information, is called networks and this concept is
called networking.
3. Types Of Network
• LAN or Local Area Network is a computer network (or data
communications network) which is confined in a limited
geographical area such as building or college campus.
• WAN or Wide Area Network spans a large geographic area,
such as a state, province or country.
• MAN or Metropolitan Area Network interconnects users with
computer resources in a geographic area or region larger
than that covered by even a large LAN but smaller than the
area covered by a WAN
5. Bus Topology
• Advantage
– Easy to install.
– Deployment costs are usually low.
– Easy to add systems to network.
– Require less cable length than other
topologies.
• Disadvantage
– Out-of-date technology.
– If cable breaks, whole network is down.
– Can be difficult to troubleshoot.
– Unmanageable in a large network.
7. Ring Topology
• Advantage
– All station on network equal access.
– It has single point of contact.
• Disadvantage
– High cost of implementation
– If any of the computers fails in the ring the
network collapses.
9. Star Topology
• Advantages
– Easy to install.
– Easier to troubleshoot
– Easy to add systems to network.
– Widely used
– Centralized management
• Disadvantages
– Costs are usually higher than with bus or
ring networks.
– If you have only one central device and it
fails, it brings the network down.
11. Tree Topology
• Advantages
– A point to point connection is possible with Tree
Networks.
– All the computers have access to the larger and
their immediate networks.
• Disadvantages
– Since the Tree Topology network is big it is
difficult to configure and can get complicated
after a certain point.
– If the backbone line breaks, the entire segment
goes down
– Difficult to configure
13. Mesh Topology
• Advantages
– It is possible to transmit data from one node to
many nodes at the same time.
• Disadvantages
– Redundancy due to number of network
connection
– Complex structure
– Difficult to identify the problem if network shut
down
16. TCP / IP Protocol
It is a 5 layer protocol. The layers are:
• Application layer
• Transport layer
• Network layer
• Data link layer
• Physical layer
17. • Network Interface(Data Link + Physical Layer) - Specifies
details of how data is physically sent through the network,
including how bits are electrically signaled by hardware
devices that interface directly with a network medium, such
as coaxial cable, optical fiber, or twisted-pair copper wire.
• Network Layer - Packages data into IP packets, which
contain source and destination address information that is
used to forward the packets between hosts and across
networks. Performs routing of IP packets.
18. • Transport Layer - Provides communication session
management between host computers.
• Application Layer - Defines TCP/IP application protocols
and how host programs interface with transport layer services
to use the network like FTP, SMTP.
19. Connectivity Devices
• Repeater
Network repeaters regenerate incoming electrical, wireless
or optical signals.
• Hub
• Can be defined as multi port repeater.
20. • Bridge
A network bridge connects network segments. It
can divide the large segment into smaller ones.
• Switch
It is used to transfer the packet from source to
appropriate output port.
21. • Router
It Connects two or more logical separate networks.
23. Introduction
• The Internet, sometimes called simply "the Net," is a
worldwide system of computer networks - a network of
networks in which users at any one computer can, if they have
permission, get information from any other computer.
• A global network connecting millions of computers. More than
100 countries are linked into exchanges of data, news and
opinions.
• Internet makes use of the internet protocol and the
transmission Control protocol.
24. Introduction
• There are various ways and means to access the internet.
With the advancement in technology people can now access
internet services through their cell phones, play stations and
various gadgets.
• With the development and the wide spread application of
internet electronic mail people from all across the globe come
together and communication has become much easier than
ever before.
25. Internet Application
• Communication
• Information
• Entertainment
• Services
• E-Commerce
26. Services Provided by the Internet
• E-mail
Electronic Mail is a method of sending a message from a
user at a computer to a recipient on another computer.
• Video Conferencing
• FTP (File Transfer Protocol)
This facility is a method of gaining limited access to another
machine in the Internet, and obtaining files from it. You need
full Internet connectivity, to do ftp interactively.
27. • Telnet
Telnet is the Internet facility that allows you to execute
commands on a remote host (another computer, most likely
one to which you do not have physical access) as if you were
logged in locally.
• WWW
The official description describes the World-Wide Web as a
"wide-area *hypermedia* information retrieval initiative aiming
to give universal access to a large universe of documents".
28. • Usenet and Mailing list
If you want to receive periodically information about certain
topics, there are two things you can do. The first possibility is
to read the news groups of the Internet.
If you do not have full Internet connectivity, you can
subscribe to a mailing list. What you have to do is to send
your name to some server, and every day you will receive an
e-mail containing news concerning the topic you have
subscribed to.
29. Commonly Protocol used by Internet
• POP3
– In computing, the Post Office Protocol (POP)
is an application-layer Internet standard
protocol used by local e-mail clients to retrieve
e-mail from a remote server over a TCP/IP
connection. POP and IMAP (Internet Message
Access Protocol) are the two most prevalent
Internet standard protocols for e-mail retrieval.
• Hypertext Transfer Protocol (HTTP) an
application-level protocol for distributed,
collaborative, hypermedia information systems.
30. • SMTP
– Simple Mail Transfer Protocol (SMTP) is an
Internet standard for electronic mail (e-mail)
transmission across Internet Protocol (IP)
networks. SMTP is specified for outgoing mail
transport.
• UDP
• With UDP, computer applications can send
messages, in this case referred to as datagrams,
to other hosts on an Internet Protocol (IP) network
without requiring prior communications to set up
special transmission channels or data paths.
31. WWW – World Wide Web
• The World Wide Web is a system of interlinked hypertext
documents contained on the Internet. With a web browser,
one can view web pages that may contain text, images,
videos, and other multimedia and navigate between them
using hyperlinks.
• There are several applications called Web browsers that
make it easy to access the World Wide Web; Few most
popular being:
o Mozilla Firefox
o Opera
o Netscape Navigator
o Microsoft's Internet Explorer.