LEARNING OBJECTIVES
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Know and understand the concepts of the internet and virtual networks
SUCCESS CRITERIA
Success Criteria:
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Be able to identify the difference between the Internet and the World Wide Web
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Explain DNS, hosting, the cloud and virtual networks.
1.4 Wired and Wireless Networks
Learners should have studied the following:
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types of networks:
LAN (Local Area Network)
WAN (Wide Area Network) -
factors that affect the performance of networks
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the different roles of computers in a client-server and a peer-to-peer network
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the hardware needed to connect stand-alone computers into a Local Area Network:
wireless access points
routers/switches
NIC (Network Interface Controller/Card)
transmission media -
LO5 - the internet as a worldwide collection of computer networks:
DNS (Domain Name Server)
hosting
the cloud
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the concept of virtual networks.
Note
The internet is not the same as the worldwide web, which is the collection of billions of web pages that are hosted on servers connected to the internet.
KEYWORDS
Internet - The largest WAN network.
World Wide Web -a collection of webpages we access using the internet.
Domain Name Server (DNS) - A directory of all the domain names and their corresponding IP.
Virtual network - A network created using software.
Networks - LESSON 4
The internet and virtual networks
STARTER
Click on the link to access the worksheet for this task.
The internet is the largest network that we use. It is a wide area network that is made up of a network of networks. The internet is the name we give to the infrastructure (all the hardware) that is required to create the network. It is not to be confused with the World Wide Web, which is the collection of webpages that we access using the internet.
A typical user on the internet uses a computer of some sort as a client in order to access data from a server. Clients can also be hardware or software. A hardware client can be any of a wide variety of microprocessor-controlled devices such as a desktop or laptop computer, a tablet or a mobile phone.
Clients can also be software, for example a web browser is client software and so is an email program. Many apps on phones and tablets such as those that look up rail timetables are examples of client software.
There are three key elements of the internet that we need to be aware of; these are a domain name server(DNS), hosting and the cloud.
lo5- The nature of the internet
lo5-domain name system server (dns)
When computers use the internet they are given an IP address. This is a unique address given to each device that is the Internet Protocol (IP) to communicate over a network. We use the IP in the TCP/IP that we use when communicating using the internet. Servers are created to store the IP addresses of each devices. Computers and network components use an IP address to route the request to view a web page to the correct site that we re trying to reach.
A domain name is the name given to a collection of web pages that we may want to view, for example ocr.org.uk. A DNS server keeps a directory of all the domain names along with their IP address.
This means that we do not need to remember the IP address to access the website, only the domain name of the website we want to access.
Each domain name ends with a set of letters that indicates which top-level domain it belongs to. These include:
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.com - a commercial business
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.uk - a business based in the UK
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.org - a non-profit organisation
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.gov - a government agency
lo5-Hosting
When a company sets up a website it will need to find a way to host it so that it can be made available for access on the internet. A host is a web server that hosts one or more websites. If a company has a number of dedicated web servers that hosts a number of different websites for other companies, this is called hosting.
It is quite difficult to host a website; there are a number of things
that needs to be considered. The host will need to be switched on
at all times, it takes a great deal of technical knowledge to keep it
operational, it takes a great deal of security to protect it against hackers,
and if it fails, any websites it holds are no longer accessible.
Therefore, there are whole businesses dedicated to hosting websites for other companies.
lo5-The cloud
The cloud is an ever growing feature of the internet. More and more businesses and individuals are choosing to use it every day.
A cloud is the name given to the remote storage of data and software that we access using a device. The data and software that we want to use are not stored on our individual device or hardware, but stored in a remote location, normally by another company. We use the Internet to access the data and software whenever we need it.
The advantages and disadvantages of using the cloud include:
lo5-The concepts of virtual network
A virtual network is one that is created using software. A business may choose to partition off its larger physical network into a number of virtual networks.The part of the network that has been partitioned off by the virtualisation software is referred to as a VLAN. By doing so it can provide each department with their own separate network by virtually partitioning off some of the physical network it has.
This can have a number of benefits for a business; including:
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It only needs to have one large physical network in place.
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Each virtual network can have its own level of security and access.
This can be set at different levels across each VLAN, depending on
the sensitivity of the information for each department.
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Bandwidth can be distributed differently across each VLAN. This means that those departments that create more network traffic can be given more of the bandwidth available.
The computers used by these people are part of a large physical network. A virtual network has been created for all those people who are marked with a star. Only they can see the information available on the virtual network. The other people are not aware that the virtual network exists.