All language subtitles for 11. Wireless LAN

In our next section we're going to talk about the violence local area networks.

And let's start with the light wireless local area network overview so why we need wireless networks

into these companies wireless networks are a powerful tool for boosting productivity and encouraging

information sharing with untethered to access to documents e-mails applications and other network resources.

Employers can roam where they need to and have constant access to the tools required to do their jobs.

That is the main reason that explains the need for the wireless networks and let's go ahead with the

advantages of the wireless.

The first advantage anchor is mobility and collaboration.

Employees who use your wireless LAN can roam around your office or two different floors without losing

their connection.

Imagine everyone in a team meeting or in small conferences having access to up to the minute communications

and all documents and applications on your network.

The second advantage is the improved responsiveness.

Customers want quick response to queries and concerns guys and a wireless network can improve customer

service by connecting staff to the information they need.

For example a doctor in a small medical office can access online patient files while moving between

exam rooms or a retail sales person can check on available inventory necessary to write up orders on

the showroom floor.

The third advantage is better access to the information.

Wireless lines allow a business to bring network access to areas that would be difficult to connect

to a wired network.

For example adding wireless access points to a warehouse can make it easier to check and manage inventory.

Providing the company with accurate inventory figures in the real time and the fourth advantage is the

easier network expansion.

Companies that need to add employees or reconfigure offices for a complete will immediately benefit

from the flexibility wireless lines provide desks can be moved and new employees can be added to the

network without the effort and the costs recur to run cables and the wires.

The most common wireless technologies used today are Wi-Fi Bluetooth why Max cellular broadband and

the satellite broadband

let's go with I Tripoli 800 and to that eleven by five standards eight unders and to that eleven refers

to a family of specifications developed by the eye Tripoli for wireless LAN technology.

These specifications.

This standard specifies and all the air interface between a wireless client and a base station or between

two wireless clients.

In this chart you can see the history and the enhancements of the standard.

The first standard is a standard and two that eleven as you can see and the maximum death rate is two

megabits per second just.

But the less than that which is eight under then two that on a C is supporting up to seven gigabit per

second and you can see the bands that the standard are using and the benefits they support and the modulation

type and advanced antenna technologies.

Let's go ahead we then worse again.

This chart explains some differences between wireless local area network and the wired LAN physical

layer component of wireless local area network is radio frequency and the physical Lear component of

the Internet is cable as you know.

Availability of the wireless LAN is everybody in the range of the access point while you need a cable

connection on the internet look we're a network to reach the network and we can face with the signal

interference for wireless local area network but it is inconsequential for the Internet local area network

and let's go ahead with the wireless network interface cards a wireless network interface controller

is a network interface controller which connects through a wireless radio based computer network rather

than a wire network such as Internet.

This card uses an antenna to communicate via microwave radiation and let's go ahead with the wireless.

More than a wireless modem is a device that provides wireless broadband connections such as DSL for

home users over the Wi-Fi.

Most of us use modem in our houses and connect to Internet by using more them or wireless.

Let's go ahead with the business wireless solutions.

When 800 to that eleven networking began all access points were autonomous mode which means that each

AP access point worked as a standalone unit with no knowledge of the or interaction among other access

points autonomous mode was fine in the beginning when wireless networking was often limited to providing

network access in common areas or broad boardrooms and continuous streaming was not a requirement.

Rather than using autonomous access points you can use lightweight access points to if you have a network

component that offers wireless local area network controller services.

In this scenario the access points all have their configuration managed but the wireless controller

you can set a single policy on that wireless controller and that configuration setting can be deployed

to all managed access points reducing the workload of managing hundreds of afternoons access points.

Let's go ahead with the wireless antennas and antenna.

Use the wireless system three fundamental properties gain direction and the polarization and we have

three types of antennas and they're only directional directional and the Yagi directional antennas are

designed to be pointed to or focus in a single direction somewhat like our flashlight only antennas

collect and broadcast signal in a 360 degree pattern similar to how a light bulb throws light in all

directions and the antenna is a directional antenna consisting of multiple parallel elements in a line

and let's go ahead with the.

That's a lie them topology mounts.

We have basically two topology much for wireless network guys and they are ad hoc mode.

And the infrastructure modes let's start with the ad hoc moment in the ad the much to the wise is connect

each other wirelessly without the aid of an infrastructure do as such as a wireless router on or access

point as you can see in here.

We have leapt up one and leapt up two and they're connected wirelessly to each other without an access

point in the infrastructure mod wireless clients interconnect via a wireless rather or access points

such as in wireless local area not in the infrastructure mode.

Wireless clients interconnect via a wireless rather or access points such as in WI Lance in basic SOS

area.

We have just won access points to connect.

As you can see in here we have a laptop one laptop two again and this guys are this time connected to

each other by the help of an access point and in extended service area.

This time we have two or more access points to connect and our laptop one is in here for example and

our laptop too is on the remote.

And as you can see and they are connected to each other by using two or more access points let's go

into the wireless LAN operations and let's go ahead with the Wi-Fi frame format in the Wi-Fi frame.

We have two birds of frame control field.

We have two points of duration field six bytes of destination and source and the rather MAC address

failed two birds of sequential control bid for but I'm sorry six parts of MAC address of the AP and

we have data payloads and the CRC fields let's go ahead with the CSM ACA carrier since multiple access

collision what the evidence is a protocol for carrier transmission it in a under then to that eleven

networks unlike CSM may see the carrier since multiple access collision that Act which deals with transmissions

after a collision has occured CSM ACA acts to prevent collisions before they happen and let's go ahead.

The declined access points connection the first the client sends air these core AP message to discover

the access point in the network then an authentication message is shared between Klein and the access

point.

Then the associate message is shared also between the client and the access point to connect an access

point.

We have five parameters and their SSI.

These security key security in network mode and the channels setting assess the idea is the short for

service set identifier and basically SSA today is the name for a Wi-Fi network.

Security is the security key is the passport that we are using to connect to wireless access point.

We can also set the security and network modes and channels settings to in wireless network guys three

cancer channels are used for communication between sender and wireless receiver devices.

If channel is used so much by clients it can saturate and to decrease the saturation.

We have different types of techniques and they're the s ss which means direct sequence spreads spectrum

FHA says which means free counseling helping spread its spread spectrum and all of them which means

orthogonal accounts in the Asian multiplex.

And that squares with the violence locally that security.

And let's start with the wireless those attacks this part recent Wi-Fi security advances wireless local

area networks remain wary vulnerable for denial of service attacks worldwide.

Traditional those attacks involve overwhelming air hosts with service requests in wireless networks

limited bandwidth and writhing functionality associated with nodes open up new avenues for launching

the those attacks.

Let's go ahead with the rogue access point term a rogue access point is a wireless access point that

has been installed on a secure network without explicit authorization from a local area network administrator.

Rogue access points can allow a hacker to conduct a man in the middle attack flood the network with

useless data creating a denial of service send for us outside advertising attractive features such as

free internet connectivity and provides a conduit for the theft of company information.

Let's go ahead with the men in the middle attack in the men in the middle attack.

Attackers secretly relays and possibly alters the communication between two parties who believe they

are directly communicating with each other.

An attacker with reception range of an unencrypted Wi-Fi wireless access point can insert himself as

a man in the middle.

Let's go ahead.

The wireless local area network configuration to configure a wireless local area network we should choose

the right network modes society channel with channel and a society broadcast or we can choose the security

application and the administration parameters as well as we can see in a year we are choosing a security

mode and we need to enter the password that we need to use while we are connecting to our wireless device.

And also we should use as security modes and ready so where we can define as ready as or rather as port

as well and we can make wireless mac filtering as you can see in here and just allow these guys to enter

our access points.