Monday, May 22, 2017

CN: Topic 6 Server

List all the different types of specialist server you can think of or find via the internet and books (e.g. mail server). Briefly describe each one

Application Servers
An application server is a type of server designed to install, operate and host applications and associated services for end users, IT services and organizations. It facilitates the hosting and delivery of high-end consumer or business applications, which are used by multiple and simultaneously connected local or remote users.
Communication Servers
A communications server is a computing system platform that is used for various network communication applications and allows vendors to add multiple values at different levels of architecture.

Domain controllers/directory Servers
A domain controller (DC) is a server that responds to security authentication requests within a Windows Server domain. It is a server on a Microsoft Windows or Windows NT network that is responsible for allowing host access to Windows domain resources.

Fax Servers
A fax server is a system capable of receiving incoming faxes, sending faxes and distributing faxes over a computer network. Software applications for most operating systems are also available to make a computer in a network act as a fax server. The incoming fax messages can be stored in any printable file format such as graphics or word processing. A fax server helps in reducing the number of dedicated fax lines needed in an environment or organization.

File Servers
In the client/server model, a file server is a computer responsible for the central storage and management of data files so that other computers on the same network can access the files. A file server allows users to share information over a network without having to physically transfer files by floppy diskette or some other external storage device. Any computer can be configured to be a host and act as a file server. In its simplest form, a file server may be an ordinary PC that handles requests for files and sends them over the network. In a more sophisticated network, a file server might be a dedicated network-attached storage (NAS) device that also serves as a remote hard disk drive for other computers, allowing anyone on the network to store files on it as if to their own hard drive.

Print Servers
A print server is a computer that can process print-related jobs on a network of computers. Print servers are connected to a computer network in order to serve the need for printing jobs in a network that may contain more than one printer. A print server usually allows users in a computer network to perform a printing job without having to move files to the computer connected directly to the printer.Also known as printer server or network printer, (although the latter is actually one of the properties of the print server).

Mail Servers
An email server, or simply mail server, is an application or computer in a network whose sole purpose is to act as a virtual post office. The server stores incoming mail for distribution to local users and sends out outgoing messages. This uses a client-server application model to send and receive messages using Simple Mail Transfer Protocol (SMTP).

Web Servers
A Web server is a system that delivers content or services to end users over the Internet. A Web server consists of a physical server, server operating system (OS) and software used to facilitate HTTP communication.
A Web server is also known as an Internet server.


Reference:

Techopedia.com. (2017). What is an Application Server? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/432/application-server [Accessed 23 May 2017].


Techopedia.com. (2017). What is a Communications Server? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/18429/communications-server [Accessed 23 May 2017].


Techopedia.com. (2017). What is a Domain Controller? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/4193/domain-controller [Accessed 23 May 2017].


Techopedia.com. (2017). What is a Fax Server? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/15227/fax-server [Accessed 23 May 2017].


Techopedia.com. (2017). What is a Print Server (PSERVER)? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/3619/print-server-pserver [Accessed 23 May 2017].


Techopedia.com. (2017). What is an Email Server (MTA)? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/1660/email-server [Accessed 23 May 2017].


Techopedia.com. (2017). What is a Web Server? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/4928/web-server [Accessed 23 May 2017].


SearchNetworking. (2017). What is file server? - Definition from WhatIs.com. [online] Available at: http://searchnetworking.techtarget.com/definition/file-server [Accessed 23 May 2017].

Thursday, May 4, 2017

CN Topic 3: Wireless Network

Explained wireless network and Wifi identify the advantages of wireless network.

Wireless networks are computer networks that are not connected by cables of any kind.

Wi-Fi is the name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections.

Advantages of a Wireless Network


  •  Users can move around freely within the area of the network with their laptops, handheld devices etc and get an internet connection.
  • Users are also able to share files and other resources with other devices that are connected to the network without having to be cabled to a port.
  • Not having to lay lots of cables and put them through walls etc. can be a 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.
  • If you are a business such as a cafĂ©, having a wireless network that is accessible to customers can bring you extra business. Customers generally love wireless networks because they are convenient.
  • Wireless networks can sometimes handle a larger amount of users because they are not limited by a specific number of connection ports.
  • Instant transfer of information to social media is made much easier. For instance, taking a photograph and uploading it to Facebook can generally be done much quicker with wireless technology.

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

Smartphone - its is used to surf internet
Laptops - it is used to surf internet
Computers - it is used to surf internet
Printers - its is connected with another device


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.

The 802.11g specification is a standard for wireless local area networks (WLANs) that offers transmission over relatively short distances at up to 54 megabits per second (Mbps).

802.11n is a specification for wireless LAN (WLAN) communications. 802.11n, an addition to the 802.11 family of standards, will increase wireless local area network(WLAN) speed, improve reliability and extend the range of wireless transmissions.

Differences 802.11g and 802.11n
802.11a:
    • Operates in the 2.4GHz radio spectrum.
    • Speed: Up to 54Mbps
    • Range: 100 feet
    • Prone to interference (it shares airspace with cell phones, Bluetooth, security radios, and other devices).
802.11a:
    • Operates in the 2.4 or 5GHz radio spectrum
    • Speed: Up to 700Mbs
    • Range: 50 feet
    • Because 802.11b and 802.11g use the same radio technologies and portions of the spectrum, they are compatible with one another. But because the 802.11n standard has yet to be ratified by WECA, it may not be completely compatible with 802.11b and 802.11g.

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

·        Modulation Spectrum Technique:  The technique of spectrum modulation which wads used in the early technology of WiFi has very low security that anyone can use your network and hack your code of activity.
Solution: The solution which scientist suggest for this problem is that we can use latest model or technology of modulation spectrum to protect the WiFi fro such problem.

·        Change Default Passwords: Some hackers also hack your default password that was assign by manufacturers. Hackers used all the default passwords and hack your WiFi network.
Solution: When you use the WiFi system you should change the default password as soon as possible and set a new password of your choice.

·        Wireless Equivalent Privacy (WEP): Some people also suggest for using Wireless Equivalent Privacy WEP to have a secure working on WiFi network. Sometimes it is very insecure to use WEP technology because it is very easy to break the encryption of WEP.
Solution: This security problem of WiFi can be reduced by upgrading the wireless encryption to Virtual Private Network (VPN).

·        Crackers: One of the major problems of WiFi security are crackers.
Solutions:  We can prevent the crackers by using the no. of methods of recovery of WiFi security such as placement of access points in the desired area, as WiFi is the combination of both wireless and the wired devices so, by dividing the both portions in the different segments we can avoid such problem of crackers.

·        Service Set Identifier (SSID):
Another major security problem of WiFi security is breaking of service set identifier SSID. It is very easy and convenient to break the service set identifier SSID by anyone with the help of any kind of sniffing tool.
Solution: This problem of WiFi can be overcome by using the encryption technology such as RADIUS etc. By applying encryption of data we can protect our SSID.

Find at least 4 wireless networking protocols and explained each examples.

Bluetooth is a telecommunications industry specification that describes how mobile phones, computers and personal digital assistants (PDAs) can be easily interconnected using a short-range wireless connection. 
Ultra wideband (also known as UWB or digital pulse wireless) is a wireless technology for transmitting large amounts of digital data over a wide spectrum of frequency bands with very low power for a short distance (up to 230 feet) and carrying signals through doors and other obstacles that tend to reflect signals at more limited bandwidths and a higher power.
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. Designed to provide a WLAN with a level of security and privacy comparable to what is usually expected of a wired LAN, Wired Equivalent Privacy (WEP) is a security protocol, specified in the IEEE Wi-Fi standard, 802.11. Another security standard for users of computers equipped with Wi-Fi wireless connection is Wi-Fi Protected Access (WPA). It is an improvement on, and is expected to replace, the original Wi-Fi security standard, WEP.
802.11 is an evolving family of specifications for WLANs developed by a working group of the Institute of Electrical and Electronics Engineers (IEEE). There are several specifications in the family, and new ones are occasionally added.

Reference:

Techopedia.com. (2017). What is Wireless Network? - Definition from Techopedia. [online] Available at: https://www.techopedia.com/definition/26186/wireless-network [Accessed 2 May 2017].


Webopedia.com. (2017). What is Wi-Fi (Wireless Networking)? Webopedia Definition. [online] Available at: http://www.webopedia.com/TERM/W/Wi_Fi.html [Accessed 2 May 2017].


TurboFuture. (2017). Wireless Network vs Wired Network: Advantages and Disadvantages. [online] Available at: https://turbofuture.com/computers/Wireless-Network-vs-Wired-Network-Advantages-and-Disadvantages [Accessed 5 May 2017].


SearchMobileComputing. (2017). What is 802.11g? - Definition from WhatIs.com. [online] Available at: http://searchmobilecomputing.techtarget.com/definition/80211g [Accessed 5 May 2017].


SearchMobileComputing. (2017). What is 802.11n? - Definition from WhatIs.com. [online] Available at: http://searchmobilecomputing.techtarget.com/definition/80211n [Accessed 5 May 2017].


Att.com. (2017). Differences between 802.11a, 802.11b, 802.11g and 802.11n. [online] Available at: https://www.att.com/support_static_files/KB/KB3895.html [Accessed 5 May 2017].


SearchNetworking. (2017). Wireless protocols learning guide. [online] Available at: http://searchnetworking.techtarget.com/tutorial/Wireless-protocols-learning-guide [Accessed 5 May 2017].




Topic 7: Wireles Network Hardware

Wireless Router is a device in a wireless local area network ( WLAN ) that determines the next network point to which a  packet  should be...