So it's time to start now.
And let's go ahead with our first section introduction to networks in the section we're going to talk
about basics of network Les whens and the Internet and network tunes and security overview.
All right let's go we're starting now training with an interesting graphic.
This graphic shows us number of the ways is connected to the Internet worldwide.
As you can see
there were eight billions of devices connected to the Internet but it is assumed to be 50 billions.
That is a really crazy number of guys.
And that means we will need much more resources such as bandwidth and stronger devices and more secure
networks.
Let's go ahead with the global community networks.
Nowadays we may often need to meet people from different parts of the world especially global companies
can often hold meetings with employers in different locations.
However it can be very difficult for all employees to come together at the same location for each meeting
both in terms of time and cost.
Cisco has two great solutions for eliminating this time and cost problems.
The first solution is video conference video conferencing is a technology that allows users in different
locations to hold face to face meetings without having to move to a single location together.
This technology is particularly convenient for business users in different cities or even different
countries because it saves time expands and hassle associated with business travel.
The second technology we are going to focus on is telepresence video conferencing technology isn't always
able to do so.
Barriers and facilitate remote collaboration.
Cisco TelePresence recreates the meeting room experience so you can meet face to face with your globally
dispersed teams.
Now in-person meetings can be happen without the hassle of travel so you can be more available and more
effective than ever before.
The Cisco TelePresence experience delivers high quality audio and high definition video already reliable
IP network.
Unlike video conferencing your meetings will look and sound as if all the participants are actually
together in the same room.
Here is the telepresence device as you can see in here.
These guys are maybe in par is.
And these guys are for example in Tokyo.
But what they feel is as you can see they're on the same table.
That's a really great and cool technology.
Now let's talk about the variety of networks according to their size.
Small Home Office networks are networks of several pieces laptops and printers and it means basic requirements
such as surfing on the Internet.
For example medium sized networks usually consist about 15 or 20 pieces laptops and just a few printers.
Maybe if these networks also a network was such as savage or rather can be used which we will see in
more detail later let's go ahead with the large and worldwide network.
Large networks are geographically this through building networks in such networks where powerful network
devices are used to provide communication between the ends.
A simple example of these networks is simply Internet or we can think about a global company such as
Cisco and Cisco uses the large networks to provide communication between different locations such as
Cisco Australia Cisco pond and Cisco China an absolute between different buildings let's take a look
to Klein and server concepts now.
These guys are the Klein's and this guy is the so our clients are the devices such as pieces smartphones
and laptops that request a service from the servers and servers are the devices that provide the requested
service to the clients.
Servers are classified by the service they provide.
For example a web server serves as a web page and files server service computer files and something
like that.
The client established that connection to the server over a local area or wider network such as the
Internet maybe once the server has fulfilled the client's request.
The connection is terminated.
For example let's say that this P.C. want to connect with the Google's web page and let's say that this
is the web server off to Google.
If you want to connect Google's web page your PSC is the client which request the web page and Google's
web server provides you the requested service which is a web page for this situation.
And let's go ahead with the lands winds and the Internet let's first talk about the ways that we can
use in our network.
There are two types of devices and there and devices and the infrastructure devices the network devices
that people are most familiar with are called and devices are hosts.
These devices form the interface between users and the underlying communication network.
Some examples of end devices are computers network burners VOIP phones telepresence employees security
cameras and something like that.
Infrastructure devices are the devices that helps to provide communication between different and devices.
For example you can communicate different pieces by using switch on the same local area network as an
example.
We can do surveys access points routers and firewalls to the infrastructure devices and let's go ahead
with the network media network.
Media refers to the communication channels used to interconnect nodes on a computer network in a network.
We can put communication in two ways and they're wired and wireless in a VOD media.
We use different types of cables such as copper cable or fiber optic cable to provide communication
between different devices wireless network media provides communication between two or more networking
devices that are not connected by a cable.
The most common wireless technologies use radio waves with radio waves.
Distances can be sharp such as a few meters for Bluetooth or as far as millions of kilometres for deep
space radio communications and network infrastructures can where I greatly in terms of size of the area
covered numbers of connected users numbers and types of services available.
Basically we have four types of networks and they are local area network wider network Metropolitan
Area Network and Storage Area work
local area network LAN is a network infrastructure that provides access to users and and devices in
a small geographical area learns the interconnect and devices in a limited the area such as a home school
office building or campus and land is usually administered by a single organization or the individual.
Let's go ahead with the wider network wider in a work van is a network infrastructure that provides
access to other networks over wide geographical area.
This is the difference from the local area network.
Winds are typically managed by service providers or Internet service providers and they interconnect
different local area networks over wide geographical areas such as between these states provinces countries
or something like that.
In the figure you see a van infrastructure and here there is a London office in here.
There is a Dallas office in here.
There is a Washington office and in here there is a barrel and local area work and wider network interconnects
this different local area networks between different countries.
Let's go ahead with Metropolitan Area Network and man is the network infrastructure that spans a physical
area larger than a local area network but smaller than a wider network man's metropolitan area networks
are topically operated by a single entity such as a large organization a storage area network is a network
infrastructure designed to support file servers and provide data storage retrieval and replication.
It involves high end servers multiple disk arrays and Fibre Channel interconnection technology although
there are benefits using locally network or wider network.
Most individuals need to communicate with a resource on another network outside of the local network
within the home campus or organization.
This is done using the Internet.
The Internet is a worldwide collection of interconnected networks cooperating with each other to exchange
information using common standards through telephone wires fiber optic cables wireless transmissions
and satellite lengths.
Internet users can exchange information in a variety of forms but how we can connect to Internet.
We have some options for this.
The first option we're going to check as DSL digital subscriber line technology digital subscriber line
is a family of technologies that are used to transmit digital data over telephone lines in telecommunications
marketing the term DSL is widely understood to mean a DSL the most commonly installed DSL technology
for Internet access DSL service can be delivered simultaneously with what a phone service on the same
telephone line since DSL uses higher frequency bands for data.
Here is how we can connect to Internet by DSL.
Here is your computer to us.
And you collect your computer's network interface card through.
Was named more than this modem device is connected to a little otherwise little equipment named splitter
which splits the telephone and the data frequencies.
The other side of the splitter is connected to your phone and splitter is connected to
the wise name.
The Islam on the ISP side and this.
This is
connected to ISP backbone and this backbone.
Takes you to the Internet simply.
You can also connect to Internet by using cellular or mobile network a cellular network or mobile network
is a communication network where the last link is wireless.
The network is distributed over land areas called cells.
It's served by at least one fixed location transceiver but normally three cell sites or base Transceiver
Stations.
The most popular cellular network in communications are 3G 4G and that's going to be 5G in the future
satellite.
Internet access is the Internet access provider through communication satellites.
Modern consumer grade satellite Internet service is typically provided to individual users through geostationary
satellites that can offer relatively high data speeds up to 50 megabits per second.
And here's how we can connect to Internet by using satellites.
Here is our P.S. And our P.S. is connected to satellite rather.
This time satellite rather is connected to the antenna and these antennas are communicating each other
by using satellite this satellite for its packets through internet site and you can access the Internet
by using this antenna and Nook hop and other internet connection.
Option is Metro Ethernet Metro Internet network is a metropolitan area network that is based on Internet
standards.
It's commonly used to connect subscribers to a larger service network or the Internet.
Businesses can also use metropolitan area Ethernet to connect their own offices to each other and in
the third step.
We'll talk about network trends and security overview the first one we're going to talk about is the
why or the bring your own device.
Bring your own device refers to the policy of permitting employers to bring personally own devices such
as laptops tablets and smartphones to their workplace and to use those devices to access privileged
company information and applications and let's go ahead with the.
Another trend which is online collaboration.
Simply put online collaboration lets a group of people work together in real time over the Internet.
Those engaged in online collaboration can work together on word processor documents PowerPoint present
presentations and even for brainstorming all without needing to be in the same room at the same time
there another trend is cloud computing.
Cloud computing is a delivery of computing services such as servers storage databases networking softwares
or something like that over the Internet which is known as the cloud.
Companies offering these competing services are called cloud providers and topically charge for cloud
computing services based on usage similar to how you are billed for water or electricity at home.
Instead of having to invest heavily in data centers and servers before you know how you are going to
use them you can only pay when you consume competing resources and all the pay for how much you consume
and let's go ahead with the data centers.
A data center is a facility composed of networked computers and storage that businesses business or
other organizations used to organize process store and this emanate large amounts of data.
Data centers are not a single think guys but rather a conglomeration of elements.
At a minimum data centers serve as the principal repositories for all manner of I.T. equipment including
servers storage subsystems networking tweets Rather's and firewalls as well as the cabling and physical
racks used to organize and interconnect the I.T. equipment a data center must also contain an etiquette
infrastructure such as power distribution and supplemental power subsystems including electrical switching
on interoperable power supplies backup generators and so on.
When isolation and datacenter cooling systems such as computer room air conditioners and other kit provisioning
for network carrier connectivity and let's take a look to the smart houses a smart home is a residence
that uses Internet connected devices to enable the remote monitoring and management of appliances and
systems such as lighting and here think smart home technology also known as the home automation provides
homeowner security comfort convenience and energy efficiency by allowing them to control smart devices
often by a smart home application on their smartphone.
For example when you are outside on a hot summer day you can cool your home by running the air conditioner
remotely by using your smartphone
and another trend is Power Line networking power line networking as its name implies uses your existing
electrical power cabling to transmit digital data.
In this case it is used to transfer your networking data.
This can essentially be told of acting like a wire network where your electrical wiring replaces a large
segment of unsightly Internet cable power line.
Networking is a good alternate that can often be used in situations where wiring is difficult and let's
go ahead with the network security threats.
Guys it's a dangerous world out there in the world wide web just as your mother may have told you to
never talk to strangers.
The same advice holds true for the virtual world.
You may know to be wary of viewing strangers your business bank account details.
But can you be sure.
Web site you're looking into is that of your bank and not a folder created by a cyber criminal cyber
criminals.
Use many different methods to lure you into parting with your confidential personal or business information.
As a small company doing this on its own on the Web you need to be aware of these methods so you can
be extra vigilant when online the common network security treats you can face are those attacks wires
worm malware spam phishing and something like that.
We'll discuss deeper about this concept on our later lessons and yes we have security threats but fortunately
we have solutions to to mitigate network security threats.
We can use ACL access control list which is a control mechanism firewalls which is a network security
device and antivirus which is then network security software.
We will also discuss deeper about this concept on our later lessons.