Wednesday, May 3, 2017

COMPUTER NETWORK | TOPIC 3 | WIRELESS NETWORK



1.      Explain wireless network and Wi-Fi. Identify the advantages of wireless network.

Wireless networks - use radio waves to connect devices such as laptops to the internet, the business network and applications. When laptops are connected to Wi-Fi hot spots in public places, the connection is established to that business’s wireless network.
           
            ADVANTAGES OF WIRELESS NETWORKS
·         Users can move around freely within the area of the network with their hand held devices.
·         Users are able to share files and other resources with other devices that are connected to the network without having to be cabled to port.
·         Not having to lay lots of cables and put them through walls etc can be considerable advantage in terms of time and expense. It also makes it easier to add extra devices to the network, as no new cabling is needed.
·         Having a wireless network in a business can attract more customers  as they love wireless networks because of convenience.
·         Instant transfer of information to social media is made much easier.

Wi-Fi – a facility allowing computers, smartphones, or other devices to connect to the Internet to communicate with one another wirelessly within a particular area.


2.      List all of the wireless devices in your home and college. Briefly explain the purpose of each device.

·         Laptop – typing or watching can be done anywhere around the house
·         Mobile phones – Communication is easier as compared to landlines, more people are able to contact different people at the same time.
·         Printer – It can be accessed through Wi-Fi so we do not have bring the file that we need to print close to the printer.
·         Router – It is used to connect different devices to the internet at the same time.
·         IPad – Similar to the use of laptop but much more portable.

3.      Research the IEEE 802.11g and 802.11n standards. Explain the key points of each standard including the data rates & make comparison between the two standards.


802.11g
802.11n
Explanation
   Is backward compatible with wireless B devices. Odds are that you do not have a device that only supports Wireless B, but if you do then this is a benefit. As you can see, the man benefit of a Wireless G router over a Wireless B router is speed.
      Wireless networking standard created to improve network throughput (maximum speed and transmission capabilities) over the two prior standards

     Uses technologies including OFDM and MIMO to enable it to provide high speed data transfer at 600Mbps peak
Transfer rate
54mbps
600-900 mbps
Frequency
2.4GHz
2.4GHz / 5GHz
Wireless Channel Width
20MHz
40MHz
Usage
·    Only few computers at home
·    Usage is for checking E-mail and reading news or blogs

·    Several Computers at home using high-bandwidth sites like YouTube at the same time
·    Downloading a lot of large files
·    When online gaming
range
·    50 feet
·    175 feet



4.      Explain the different wireless network security risks and give the possible solution un order to avoid these risks.

·         DENIAL OF SERVICE – a valid user is denied the services offered by the network as the network resources are occupied by the attacker who continually bombards a targeted AP (Access Point) or network with bogus requests, premature successful connection messages, failure messages, and/or other commands.
Ø  DATA PROTECTION WHILE TRANSMISSION – This is done as mentioned before by encrypting the transmitted data. Even though being a challenge, it’s essential, by translating the data into a language which only intended user understands.
Ø  GRANTING ACCESS TO AUTHORIZED USERS – Give unique login IDs and passwords for authentication.

·         MAN-IN-THE-MIDDLE ATTACK – it is executed when a hacker logs into a computer which he uses to access the wireless card which can be used to sniff the network traffic.
Ø  WPA AND WPA2 – These standards are certified by the Wi-Fi Alliance providing enterprise solutions. It provides mutual authentication for verifying individual users.

·         MAC SPOOFING – here, the network cracker listens to the network traffic and is able to know the MAC address of that computer which has an access to the network, some software’s allow the cracker to pretend it has the desired MAC address and it can fool the network by granting access to it.
Ø  RF SHIELDING – Some schemes can be used to prevent wireless network signals from propagating outside the network premises. This can be very helpful against eavesdropping and it makes it difficult to receive the signals from the hackers.

·         JAMMING ATTACKS – This type of attacks can be executed in a Wi-Fi network to disrupt its communication. The attacker floods the Wi-Fi spectrum with powerful signals on the same frequency, which interferes with the communication between the AP and its users.
Ø  VPN – it can provide security to the users using mobile devices and want to access the network. The data tunnels through two or more points on a network using encryption so it is protected when being transmitted over unsecured networks such as the public internet


5.      Find at least FOUR (4) wireless networking protocols and explain each protocols

·         WAP – (Wireless Application Protocol) is a specification for a set of communication protocols to standardize the way that wireless devices can be used for Internet access.
·         NFC – (Near Field Communication) used for very close communication. When you wave your phone over a card reader to pay for groceries.
·         WEP – (Wired Equivalent Protocol) a security protocol specified in the IEEE Wi-Fi standard
·         WPA – (Wi-Fi Protected Access) the improvement of WEP and possibly to replace it.
·         Bluetooth – is a global 2.4 GHz personal area network for short-range wireless communication. Device-to-device file transfers, wireless speakers, and wireless headsets are often enabled with Bluetooth
·         ZigBee – is a 2.4 GHz mesh LAN protocol.
·         Z-Wave – is a sub-GHz mesh network protocol, and is proprietary stack. It is often used for security systems, home automation and lighting controls.

REFERENCE




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