P5 Introduction

P5
This is my blog where you will be able to find information on the typical services provided by networks this include directory services , application services and more. This unit is all about computer networks, and in particular this assignment is about the services that a network provides and the services that are available from a network operating system, throughout my blog i go into more depth.

Directory Services

Directory services 
A directory service is basically a network service that is capable of storing resources that will then available for the user to use such as e-mail addresses and devices like printers. Also the directory stores permissions and accessible rights for the users also it can make it easier if you wanted to access a different server you could would be able to via the server name as oppose to typing in the whole IP address. On many occasions more than one server is used the reason behind this is that it can speed up a process such as searching for someone credentials if a user for the school can log on to the network this will searched what the user typed in on the database and if it is a big school it will be quicker rather than all the students data on one server. 

Active directory 
Active directory is a directory service which is built-in most server operating systems. It is responsible for authenticating all users and computers on the network and putting up security policies for all computers within the network as well as installing or updating to the latest software. It is also the main location for network administration and security such as when a user logs into a computer within the network Active directory identifies whether this person is a normal user or the system administration. All this is done by the domain controller which is the server and it basically handles the authentication management. When you log in the information is checked by the domain controller this is done for the user as well as the computer.  If they are not on the database then they will simply not be allowed to access the network. A perfect example is a student trying to log onto the school network. DNS this is Domain name server and basically translates domain names into IP addresses. When the active directory is in use the DNS use the computer and checks by its DNS and if its DNS is on the database then it is allowed to connect to the network and if it is not allowed then the device would not be allowed onto the network.  

Also when there is new students that join the school they will need to have credentials created to allow them to log on and access the network. They would also have a default username which can never be changed and password which they can change, also in our particular school as soon as a student has left the school and after a year they are removed from the database which frees up space on the server for the new Year group. Also in our school these are separated into particular groups which is year groups and these are identified by the year that they account was created for example if a student joined the school 2009 then there log In would be 09 then there surname. 

Telecommunication Services

Telecommunications is a variety of technologies that send information this includes Mobiles and telephones these are all examples of telecommunication technologies also radio and television are other examples of telecommunications.

E-mail

An email allows you to communicate with anyone in the world as long as they an internet connection and have an email account. Many popular email websites are Hotmail and G-mail both these allow you to send messages as well as documents as attachments. The user that is using the software is an able to send the recipient as many messages as they want to as well as send the emails for free as long as they have the other person’s individual address. Below is a picture that shows the basics an email works. Also with the introduction of 3G people can now read their emails when there not at their computer e.g. smartphones. 

IRC(Internet relay chat)

Internet Relay Chat (IRC) is online instant communication chat which is done over the Internet. The main design of IRC’s is to for users to chat openly to each other via an internet connection also this  can be multiple people chatting at one time across large distances for example three people could be in a chat and all in different countries. Users can join the conversation and send messages to it, which shows to all the others users communicating in the same conversation. It is not only used for socializing but can also be used in work environments for example for a meeting and work conversations about specific work related tasks. The good thing about IRC is that they can also be accessed anywhere as long as they have an internet connection and the login credentials an example is talking to their boss via internet relay chat at home while the boss is in the office. MSN is a good example of this where they have add the person and cannot be added by any random stranger however there is discussion boards which can have negative affect and is discussed below.

Discussions boards

A discussions board is basically a website where a particular topic is presented and then people can discuss any questions and submit their own ideas. An example of this is Yahoo answers where someone will put out a question so that any person for searches for something similar will be able to answer the question or submit their views. However the only problem with this is that as anyone can post on the page means that people can post links to illegal websites or give people viruses. However the good thing about using discussion boards if you wanted to ask a question about something that would not be able to gather information about such as an experience someone has had people would be able to post information that may not be able to found on the websites so can be very helpful to some people. However this could have a negative effect of the person as there could put hateful messages or wrong advice and so on. 

Remote access

The basic job of remote desktop is it allows a user to enter into another computer on the user’s network. It allows to access data and applications using the Remote Desktop Protocol (RDP). A basic example of this is if a teacher wants to plan a lesson plan but they saved a file on their user area at school they will be able to log onto that school network without physically being at the school which is a major advantage. However this is only available on professional and enterprise versions of windows and other operating systems for this type of remote access software to be available. Not only can a user access there user area but also they can access servers as well and can also be accessed thought a phone or tablet. That is an example of remote access which be over a long distance as long as the IP address is available however another example which I have personal experienced is where a teacher has remote access over your personal computer and you can see exactly what they are doing e.g. showing you how to do something. There is another type of remote access which is when your computer is being remotely accessed you cannot see what they are doing, this can also be done to all PC’s in room if the teacher wants the class to pay attention without being able to access their computer.

http://www.computerhope.com/jargon/i/irc.htm

http://www.dummies.com/how-to/content/how-email-works.html

http://www.ukcle.ac.uk/resources/teaching-and-learning-practices/discussions/one/

http://compnetworking.about.com/od/internetaccessbestuses/f/what-is-network-remote-access.htm 

Author- Bradley Mitchell

File services

File services

The job of a file service is to command and to carry out task that are needed to read, update, add, delete and browse files. File Server Resource Manager is a collection of tools that allow administration to understand, control and manage the amount of data stored on their servers.  A way of sharing files is through file sharing this is done across a network however there are certain things that cannot be done by students that can by teachers and perfect example of this is that a teacher is able to put work and files on the shared drive with students only being able to open and view however if they wanted to add files to the shared folder they would not be able to due to privilege rights set by the network admin. When someone new joins the network they will be put on a list to either be able to have the privilege rights e.g. student and teacher. The good thing about putting users into groups is it makes it a lot easier to manage if there is a problem and also if they want to make certain files private they can do so. This is an example of file sharing which is basically transmitting files over a computer network or the Internet. Another file service is the management of files, when you talk about file management a good example of this is on a school server and where the individual students have their own user area. The other type is file transfer the works somewhat similarly to file sharing and is one of the more preferred options due to the fact that it is the easiest way to transfer files. The way in which it works is that the TCP manages all the data transfer and then IP would then direct the traffic to the correct network. This allows you to send multiple files across network knowing that they will be sent to the right place. 

Application Services

Application software

A server can provide several services which can be software based such as proxies and databases. The main usage for application software’s are designed computer programs to help the user to perform specific tasks. An example of this is in a school where it would be needed for word processors and using other applications such as web browsers and other applications like movie maker and other adobe software application. However the down side of having all this software’s is that the server required an example of this when it comes to the school environment is the register this well be automatically installed on all the teachers laptops and will be filtered into classes which will have the students names on as well as a picture of what they look like and their form group. Also there form tutors will be able to see this e.g. if they were late for third lesson there form tutor would then be able to ask why as so on. This also not only makes it more efficient but also means that it cannot be lost because as soon as they click save it well be stored on the schools database. This is an example of a database currently used on the school network.

Shared resources

Shared resources are devices or information on a computer that is shared within a Local area network or Intranet. This is more hardware used to share resources such as printers however that this means as long as a computer in the school is connected to the printer it can print from it, however this well need network interface cards. An example of resources being shared is emails between all members of staff as I mentioned before with register all members of staff that are on the network, well only be able to access certain things another example of this with shared resources is email a teacher can send out email to all the teachers that are on the database.

Mobile working
Mobile working is being able to connect to different networks through many different systems which includes mobiles, tablets and laptops and basically any devices that can get an internet connection. The most popular way to connect is through remote desktop which means that they can have access to their own personal computer anywhere which is useful but is not used by the average computer user as they would have to know what they’re doing.  There is also a virtual private network which allows a particular user to set up a secure connection to their own network or in many situations schools and businesses. This allows to access their files securely without the need to transfer all there files it is normally done over the internet and all you need is the details. 

http://www.webopedia.com/TERM/A/application_service_provider.html

D2- Typical Services from NOS Directory Service

I am now going to discuss the general advantages of authorisation, authentication management as well as active directory I will also be discussing the disadvantages of these and an overall conclusion.

Authentication management

The first point that I am going to discuss is authentication management first of the definition of authentication is I the person is allowed permission to enter a network so the admin can choose the specific credentials needed to enter the network for example at a school network where they would need a username and password. This is an example because this allows them to be able to login in at any computer on the network not just a specific PC like at home, an example of this is at school where there a many buildings with many computers in each block so if each computer is connecting to the network this will cut down on expensive as each person will not need an individual computer. Also each student will have their unique individual login this is a major advantage as there can be no confusion with logging also they will have their own password which they can change for safety reason and are also reminded to change it every year. Another good thing is that as all the credentials are stored on the server the teachers and technicians will be able to add or remove accounts if necessary also if a student forgets there password then it can be reset.   However a disadvantage of this that if someone finds out the password then they have instant access to the persons account, also it is minimal security so it would be easy to hack into network or individual user area.  Another example of authentication management is hardware tokens which can come in the form of key fobs or hardware which you swipe or scan as a form of identification this is a major advantage as you no longer to need to remember any login details as soon as have the key you can have access to the network which can also be a major disadvantage as if you were to lose the key then the person would have access to your account. Also the cost of buying the hardware tokens for every individual student will be costly as it Is not cheap which also means that if they were lost by a student it would be expensive to replace. Anyone can also access anyone’s account as long as they have the key or similar hardware anyone can pretend to be the user.
Another example of authentication management is fingerprint scanning this is a modern authentication technique the reason of why this is a good way is because it would only work for one person so not one could hack or attempt to gain access without it being you. This makes this a very high security authentication but it also the most expensive the software that it costs it allow finger print scanning is not used for regular schools or companies only expensive companies that would need the this high level of authentication. However a good thing about this is that if you easily forget passwords or logins there is no need to worry however many companies use a combination of one are two of these method in order there network to stay secure.







Active Directory
The next point that I am going to discuss is active directory first of an active directory is allows you to create and maintain multiple user accounts. For example when a new year group joins the school network the active directory is used to add all these accounts for the new students. Another example of when the active directory is used is when the year 11 students stay on for sixth from then there account is maintained as they will be staying on the school network but for all the other students they keep them on the network for another year this is just in case they need to come back to get work but after that they are removed to free up space on the server. Their name is automatically added as well as the year they joined the school so for example my is 09 as I joined the school in 2009, also so soon as the account is created it is easy to maintain as the account does not need to be created again at the start of the year this is a major advantage as there will be a couple hundred users in each year group and having to re add them all is very unpractical and time consuming. As there is a limited amount of space on the server each person is allocated 1 GB of memory on their own user area, which they can save work, pictures and videos etc.  Also the active directory allows certain users specific access for example in my current school there is a stupid public drive that everyone has access to on the network but only certain accounts like teachers have access to edit and add files to this public area whereas students can only read and open the files which is a major advantage as if every student could alter or edit the files then it would be very chaotic as with just teachers having permission then it allows them to put specific work on there. Also there is certain programmes that cannot be accessed but could be changed as it is all managed so if there was multiple servers they could be set to each do different roles for each and also allows the network as a whole to run smoother as a whole. Also it makes it easier to access groups and to edit or change them in any way, also then adding groups will be much less hassle when adding or removing specific users as the basics have already been created. The disadvantages are that unless you are familiar with the set up you will struggle and if you get a single bit wrong then then you will have to restart it all over again. As it not something you can just pick up and learn so if the operator of it is not experienced it can create problems such as reinstallation and so on.
 Along with the complication of the active directory another problem is that if there was a technical difficulty and the active directory went down this would create many problems in the school network. This would cause major disruptions with work and teachers lessons so is a necessity that precautions are made to prevent this and this is why the initial setup is very important. The other obvious disadvantage being the cost if it went wrong but also the software it is specifically designed for windows but this is good for our particular schools because all of our PC’s are windows but for school that are not then they would have to have the equivalent for the appropriate operating system.  





DNS
The last the thing that I am going to discuss is that the domain name server or DNS for short. This has previously been used discussed but I am going to talk more in depth and both the advantages and disadvantages. The main purpose of the domain name server is to locate specific addresses on a network via their name instead of their individual IP address making it easier to locate them. An example of this is if you want to go on Google.com you can type that address in and the DNS will find out the IP and translate is so saves you from typing the long IP address. This is used to locate and help a particular network run smoothly for example in our school if there was a problem with one of the computers but didn’t know which one they could find out the IP address then from that the computer name in order to fix the problem which is a major advantage. Also another example is that in our school there is various buildings so if a student want to send work such as through printing they are only limited to various options. For example a couple of rooms down is allowed but in different buildings across the school is not saving money from unnecessary printing or work that may get lost.

Bibligraphy 

http://www.imprivata.co.uk/products-and-solutions/authentication-management/onesign-authentication-management

http://www.ehow.com/list_6464570_advantages-domain-name-service.html

http://searchwinit.techtarget.com/answer/Advantages-and-disadvantages-of-DNS-on-domain-controllers

http://a201165.wordpress.com/2013/05/21/active-directory-advantages-and-disadvantages/

http://msdn.microsoft.com/en-us/library/windows/desktop/aa746492(v=vs.85).aspx