UNIT 9
P1- Describe the types of networks available and how they
relate to network standards and protocols
Types of networks:
LAN
Local area network (LAN) is a group of devices which are connected (minimum of two) Local area
networks can be used to share files, use devices in the network such as printers, and applications. Local
area networks can be created with hardware which is cheap, for example, network adapter cards, hubs,
and ethernet cables.
WAN
WAN stands for wide area network which is given through a telecommunications network which
connects many local area networks. In a business, WAN is made up of connections to a business
headquarters, e.g. Usually; a router is used to connect LAN to a WAN, although there are other devices
which are multifunctional which can be used.
MAN
Metropolitan area network (MAN) is a data network which is specifically created for a city or a town.
Metropolitan area network is smaller in comparison to wide area network geographically, and
Metropolitan area network is bigger in comparison to local area network geographically. In most cases,
metropolitan area networks have fast connection speeds as the network is made up of using fibre optic
cables or other cables which provide fast speeds.
PAN
Personal area network (PAN) is a network which can have a connection to a local area network and can
also be connected to networks which are bigger, such as WAN. A personal area network is made up of
devices and is made to serve a person. Some examples of devices which are used to create a personal
area network are personal computers and computer tablets.
,Network topologies:
Star
A star network topology is usually used on home environments and Local area networks. Within a star
network, computers have a connection with the centralised connection point which is usually referred
to as the hub node (Which is usually a network hub, switch or a wireless router.) Host devices are
commonly connected to the hub using an Ethernet cable. Usually, in most cases, the star network will
need more cables, which can be expensive, although the star network is more tolerant for redundancy,
which means if a cable gets damaged, the rest of the LAN will not go down.
Mesh
The mesh topology is based on having many pathways. Data which will be sent from a mesh topology
will not be required to take a pre-determined route. Mesh topology has the option of many different
routes to be able to get from the source to the desired destination. In many WAN the mesh model is the
most common. The advantage of a mesh topology is that during a time there is a high traffic volume, the
network will not be slowed down as the data has many routes to travel from. It does not matter if other
components fail as the network will not go down. Although, the mesh topology has a high setup cost,
and maintaining such a topology is difficult and expensive.
Ring
Within a ring network, each device has a connection to two other devices which creates a ring to let the
signal to go around. Each packet of data will travel only in one direction, and each of the devices will
receive the packet until the destination device receives it.
Tree
A tree network is when two or more star networks are connected. Each star network is a LAN which
there will be a central server or computer which the workstation computers are connected to. The
central computers from the star networked will relate to a bus cable. If a cable failure occurs in the star
networks, it will isolate the workstation which links to the central computer of the star network,
although only that workstation will become single. The rest of the workstations will work as normal,
although they will not be able to make a connection or communicate with the workstation with had
become isolated. If a central computer was to go down the entire network served will suffer from
performance issues or total failure, but the rest of the network will work as intended.
, Bus
A bus network will use one backbone, to connect all the devices on a network. The cable is the
procedure of transmission for the devices to communicate from one device to another. The devices
have a connection to the network using a connector which is a single interface. When a device from the
network wants to communicate with another one, it will send a message to the network, which can be
viewed from all devices which are connected to the network but will only be processed by the device
which is intended. This methodology is simple to install and requires a small number of cables which will
be cheap to maintain, although if many devices have a connection to the network, the network could
become unstable, which could lead to signal failure.
Protocols:
FTP
File transfer protocol (FTP) is a protocol on the internet used for transferring files between computers
on the internet by using TCP/IP connection. File transfer protocol requires two communication channels
which is the client and the server. The client first communicates with the server by requesting to make a
download of a file.
SMTP
Simple mail transfer protocol (SMTP) is a TCP/IP protocol used for receiving and sending emails.
Although because of the protocols limited abilities it is commonly used with other protocols such as
POP3, or a protocol such as IMAP, which allows the user to store the messages within a mailbox of a
server and download them overtime from the server this means users will use SMTP for sending out
emails and using protocols such as POP3 or IMAP for receiving emails.
HTTP
Hypertext transfer protocol (HTTP) are rules for transferring files such as videos or images on the world-
wide-web. When a user connects to a website using a web browser they are using the hypertext transfer
protocol. Http is an application protocol which works on top of TCP/IP suite of protocols.
All the above protocols require the internet. For example, for HTTP, a user cannot have access to the
world-wide website without having access to the internet. In the same way in FTP, the server and client
require a connection to the internet to request and transfer files. Also for SMTP, the emails need to be
sent to an online server to be sent to the user’s email.