Wednesday, 7 October 2015

P5 - Describe typical services provided by networks.

In this blog, I will describe typical services provided by networks and purpose of each. I will be talking about following services:
·         Directory services
·         Telecommunication services.
·         File services.
·         Application services


DIRECTORY SERVICES:
Directory services are network services which helps store, organise and identify resources i.e. email address and provide access to users. Servers are authorised by a domain to manage larger networks. On a larger network, when multiple computers are needed to be identified, administrators use domain control i.e. username, password, authentication management, etc. to control user’s login/account in the system of this organisation. In short, directory services identifies all resources i.e. email, peripheral devices, etc. allows user to access these resources.


Account Management:
ccount Management is a service that allows user to manage the account, network connectivity, etc. It allows the user to edit, add and even alter network. This service allows user to manage the account without restrictions on functions. Account management is where network monitors all the connectivity through the network. Account management allows user to access all the resources in the computer and manage all the functions. It stores and keeps all the network account and files and documents that other added users have installed. Without this service, a user wouldn’t be able to make any changes in the account if any changes are required.

Authentication Management:
Authentication Management is a process of identifying user, when they enter their username and password to logion to network system. It acts like firewall, which prevents your computer from any unauthorised access.  Authentication management will require user to have username and password so that no other user can access their network account. It keeps your network secure. The main role of Authentication Management is to add, delete and amend policies. As well as grant or revoke permission to users, applications, etc.


DNS:
DNS stands for Domain Name Server. It translates domain name of the website (written in letters) to an IP address (arranged with number and separated with decimals). For example: www.example.com translated to the address 192.0.32.10 (IPv4). The DNS stores all the domain name in one big database and draw them to correct IP address. I the correct IP address is not found, it would request the correct IP address. It allows access to any websites. Without DNS, the internet wouldn’t function properly (It will shut down quickly). Some domain names would need to be requested such as .org, .gov, etc. It monitors web and connectivity and checks any mistrustful activity.


TELECOMMUNICATION SERVICES:
Telecommunication services are provided by telecommunication provider. This is where the telephone is built inside the network and communication takes place in the computer network. Telecommunication services are technologies that helps to communicate over wide-ranging distances. This means people can talk to their family and friends over long distances. Examples: mobiles, telephones, radio, television, etc. The widespread form of communication is use of voice over internet protocol or VoIP. Data is transmitted in telecommunication circuit by an electric signal known as carrier. Telecommunication and broadcasting are supervised by ITU (international Telecommunication Union). 



Email Communication:
mail stands for Electronic Mail. This communication service is provided freely by different companies i.e. Microsoft, yahoo, Google, etc. Emails are fast and easy means of communication nowadays. People use email in their day to day life. Some use it for chatting, some for assignments, some for business purpose, etc. Email are very beneficial as they allow you to attach files (pictures, documents, etc.) along with the message you want to send. Email has different fields in it. For example: ‘To’ field allows you to write an email address of the recipient, who you want to send an email to. The ‘CC’ (Carbon Copy) field allows you to put other recipients who you want to send and receive the email to. The ‘BCC’ (Blind Carbon Copy) allows you to put other recipients, who you want to send the same email to, however this wouldn’t be notified by anyone else that they are receiving this email too. Mail Server is also known as MTA (Mail Transfer Agent), which is an application receives and sends email from and to different users respectively. Every email that is sent or received is passed through mail servers. Without mail servers, you wouldn’t be able to send emails to the person who has same email address domain as you. For example: If you have Gmail account, you will be able to send email to another email address domains (yahoo, Hotmail, etc.) but not Gmail. Mail servers has two categories: Outgoing and incoming mail servers. Outgoing servers are known as SMTP (Simple Mail Transfer Protocol) and incoming servers are known as POP3 (Post Office Protocol).



IRC (Internet Relay Chatting) Communication:
This is quite an ancient way of communication. IRC was established in 1998. This is text based online instant communication service where people communicate with each other with single as well as multiple users (group chatting). The conversation is takes place in a virtual room (channel) where group of people send and receive messages. These messages are visible to all the users in that group. A user can join the conversation and send messages, however the user needs to have IRC client or web interface that connects the user to IRC server. This type of conversation can be used mostly in companies, organisation and other conferences where there is a group discussion about some important topic. This is wide-ranging communication service where anyone can contribute their ideas and discussion from around the world. Additionally you can also share and transfer files.



Discussion Boards:
Discussion boards are online forums which allows people to ask question by posting questions as well as commenting on someone’s post. They post questions to gain answers, which can be answered by the members of the same discussion forum. Discussion boards are mainly used for education purposes. For example: Students post questions and discuss about topics to gather information about that topic. The most common discussion board for student is www.thestudentroom.co.uk. Some people create discussion forums to seek answer for their questions while others create it to discuss about their interest and hobbies. Anyone can discuss the information, comment and give their opinions about it. There are variety of discussion boards nowadays i.e. education, games, interest, fashion, etc.


Remote Access via mobiles:
This means you can access your files, document, etc. (saved in your computer) from your mobile phone, when you are not near your actual computer. This means having control on your home computer from other location. Nowadays, mobile phones have great remote access as you can connect to an internet from your mobile phone alike sitting on a computer. You can also see LIVE CCTV footage of a security camera inside your house if any thief enters your house in your absence. Mobile Phones also used some internet apps such as Facebook, twitter, instagram, etc. Mobile phones can also be used to share and store music, videos, photos, etc. People use it mostly for browsing nowadays. Remote access via mobile is cost effective as for businesses it would save the cost of travelling for employees and office space as they could access their files and documents through mobile phones.



Social Networking:
This is an online platform which allow users to interact on web through their computers, tablets, mobile phones, etc. Nowadays, most widely used social networking sites are Facebook, Twitter, Instagram, Flickr, Watsapp, etc. where people create their profile by updating details i.e. interest, hobbies, etc., uploading photos, etc. These social networking sites allows people to socialise while sitting at home or sleeping on their bed. They do not need to meet each other in order to communicate. People upload their photo to represent them. They share their feelings, chat, post photos, status, etc. People also used these networking sites to chat to their family or friends overseas or even video chat them (seeing each other face to face using camera). Some networking sites or applications are also used to business purposes to communicate among employees i.e. Watsapp to send messages for business purposes.




FILE SERVICES:
File services helps to manage files in a network computer. File services are required so that the user can share data within an organisation, building, etc. It allows you to send information over a network. A user doesn’t have to transfer files to external hard drive or other device, they can do it using file services.  File services also stores file so that user can backup files when needed. Some examples of file services are: File Transfer and File Sharing.



File Transfer:
File transfer is a very common type of service which allows user to transfer files to other user on a network. There are number of different ways to transfer files. For example: File can be attached to email and sent to other source of computer. Additionally it can also be done through messenger. File transfer allows user to send and receive files from different users. To transfer files, a user would need to use FTP. FTP stands for File Transfer Protocol. It is an application layer protocol. It uses Internet’s TCP/IP protocols. It is used to transfer web page files and other files between client and server. It is also used to download files and programs to your computer. You can also update file at a server. FTP requires two connections between client and the server to transfer file successfully: one for Commands and replies and other for the file transfer. The client sets up the connection to server consisting of commands and client then replies. File transfer can happen in both directions: Client can pull (download) a file form the server as well as push (upload) a file to the server.



File Sharing:
File sharing means sharing out file, programs, images, video, etc. with other user. You can share your data with public with more than one user as well as privately with one or two or fewer users. A group of people can do a combined work by reading, viewing and modifying the same file at a same time. This could be done by online sharing such as Google drive, etc. When a user creates a file, he/she would decide and select the people that can access this file. This is a secure and quicker way for people to access files and share information within the organisation. File sharing is mainly used in organisations and educational purposes. Companies use file sharing to share their presentation and other important documents. Students use file sharing for group work i.e. coursework, project, etc. File sharing makes it easier for user to back up files and reduce the number of programs on any given network. This service is very easy which allows to send data on a LAN.



APPLICATION SERVICES:
Application services manages software based services and providing solutions to user over a network. These services provides communication used in peer to peer network or server network. These services also allows you to access files on the network and other software applications.



Database – Application Software:
Application software helps the user to perform different tasks. This could be for business purpose, educational purpose, general purpose, etc. Database is an application software which allows you to keeps lots of important data together in one system/form saved in a computer. Data saved in database are secured. Database is mainly used by businesses to keep the record of their sales as well as customer details. Schools use database to keep the record of their students’ attendance, etc. It is easy to find data/record of something from the database when there is lots of data. Database also allows you to create forms, queries, reports, etc. This helps to keep your database organised and structured.



Proxy:
Proxy server is like VPN. It is a secured service which helps your network from harmful sites by blocking them. A proxy server is a dedicated computer that allows computer network to indirectly connect to other network services such as web source, image, file, etc. A client is not directly connected to an internet source. He/she is connected to the proxy server and proxy helps client to connect to internet and request file, etc. available on different servers. If the user accesses the page on internet, proxy server saves that webpage. This helps proxy server to find that webpage quicker form cached memory. So if more than one website is opened or frequently used, they can be stored in proxy cache. The purpose of Proxy Server is to scan for viruses and malware and speed up access to internet resources. Proxy server helps to speed up the internet. It is used in school to block sites which are inappropriate or harmful.



Printing – Shared Resources:
Shared resources are devices shared between different users on a network. For example: Printing. In schools and businesses, all or most users (group of workstations) are connected to one printer. Any user can print using that printer. This will save the cost of investing on a new printer for schools and businesses as they are sharing one printer among different users. If there are number of users who wants to print their work, document, etc. they will have to wait in a queue as the printer will print the document for the first user first. You can also connect the printer from your mobile phone. Shared resources could be anything shared between users. For example: Data or information in Google drive, etc.



Storage Space – Shared Resources:
A storage space is an application service that allows you to stores different type of data and files you have and keep them safe on your computer. This could be games, music, videos, etc. The type of storage space could be internal, external or online. Internal storage space means data stored inside the computer i.e. hard drive. External storage space means data/files stored in external drives i.e. USB Pen drive, external hard drive, etc. Online storage space is more secure and can be shared with multiple users. This can be cloud storage or Google storage, where files are secured and can be access by other users you want. The best example for this could be storage space allocated to each student in school, where they are able to save their work and keep it secured. Shared storage space could be when teacher uploads assignment on network storage space which is accessible by all students in that class.



Voice over IP (VoIP):
Voice over IP is a Voice over Internet Protocol that changes analogue signals to digital data. Voice over is an application service that allows communication through audio or video over internet. Nowadays this service is used in mobile phones (Smartphones) to send voice messages as well as video call each other using Wi-Fi or 4G. Additionally a user can make a phone call over internet using IP phone type or other application which consumes packets of data. However VoIP could be free if two users are calling each other from same service provider. For example: Both users have Giffgaff sim card and thus call each other would be free. People nowadays use Skype and other online Voice over applications to communicate with their friends and family overseas. These voice over applications are cheaper and easier to use.



Mobile Working:  

Mobile working is when people use their mobile phones to complete their tasks i.e. browsing on internet, viewing, reading or writing a word document, scanning, printing, etc. Technology has advanced so much that user can download an app in order to remote access his/her computer at home or home security CCTV cameras as I explained earlier. This is advantageous for most of the students because they can access their files, documents, etc. that is on their home computer while they are outside home with their friends or friend’s house. You can also connect to printer using your mobile phone. A mobile also allows you to connect to internet through VPN (Virtual Private Network), which is secure network. The most advanced version of internet mobile technology is 4G network. 4G is an advanced version of 3G. 3G is a 3rd generation cellular network. Internet is accessible through mobile phone nowadays. 3G in theory offers a speed of 7.2 Mbps. In 2G the way of transmitting and receiving digital data through usual circuit switching method, but in 3rd generation, it has changed to packet-switching. However, the latest cellular network service is 4G. This makes internet faster than 3G (5 times faster). It offers HD quality video streaming. It uses WAP (wireless Application Protocol). This allows to be always on connection to the internet. This can be used by businesses to send emails and small files to one another quickly.