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Structure of the Internet - Coggle Diagram
Structure of the Internet
Internet
network of Inter-connected Networks
World wide web
a collection of resources accessed via the Internet
backbone
the main part of the Internet
a set of dedicated connections that connect several large networks at various points on the globe
IP address
unique identifier of a device
URL (Uniform Resource Locator)
are used to specify the means of accessing a resource across a network and its location
formed of the protocol and domain name
Domain Name System (DNS)
dedicated computers with an index of domain names and their corresponding IP addresses
when a computer queries a DNS server for a domain name, the server returns an IP address that the computer can use to send a message
Network
types of network
Local Area Network (LAN)
two or more computers connected together within a small geographical area
Wide Area Network (WAN)
collection of computers connected over a large geographical area
topologies
definition
the arrangement of the various computing devices which make up a computer network
Bus topology
an arragement where nodes are connected in a daisy chainby a single communication chanel
operation
each node is passive
data is sent in one direction ar a time only
each end of the backbone is connected to either a terminator or a computer which stops signals 'bouncing back'
only one computer can transmit successfully at any one time
all nodes are connected to a single backbone cable
advantages/disadvantages
+devices can easily be added
+good for small networks
+cheap to set up
-main cable is a point of failure
-limited cable length
-performance degrades with heavy use, owing data to 'collisions'
-poor security
Star topology
an arrangement where a central node or hub provides a common connection point for all other nodes
operation
computers are connected to a central node. This is often a switch, which sends each communication to the specific computer it is intended for
advantages/disadvantages
+good performance
+more secure if a switch is used as data is sent only to the recipient
+easy to isolate problems
-can be expensive to set up because of the length of cable required
cantral device is point of failure
physical topology
defines how the devices are physically connected
logical topology
defines how the devices communicate across the physical topologies
Wi-Fi
a wireless networking technology providing high-speed Internet and network connections
devices connect to the Internet via Wireless network Access Point (WAP)
wireless components
A station consists of a computer and an NIC
stations share a radio frequency channel
Wireless Network Interface Card (NIC)
Wireless Access Point (WAP) requires a connection to a router, and the router requires a connection to a modem
performance
is influenced by
bandwidth
the amount of data that can be transferred in a given time
The greater the bandwidth, the better the network's performance potential.
Bandwidth is shared between all active users, so performance can decrease if there are too many users
chice of hardware
wired vs wireless
Wireless performance depends on how well a computer can pick up the signal but is rarely better than a wired connection would be
Wired networks are usually much faster and more reliable
topology
Internet registries
they are responsible for allocating IP addresses to specific domain names
Domain name
.com;
.uk;
.net;