19/A.P1 Explain the need for different computer network types and
models.
Local Area Network (LAN):
A Local Area Network (LAN) is a network that links devices within a limited
physical area, like a building or campus. LANs are typically under the ownership
and control of a single organization. They enable connected devices to share
resources, such as files, printers, and applications. LANs offer high-speed data
transfer and low latency, enabling efficient communication among devices.
Wireless Local Area Network (WLAN):
A Wireless Local Area Network (WLAN) functions similarly to a LAN but utilizes
wireless communication technologies, such as Wi-Fi, instead of physical cables.
WLANs provide flexibility and mobility as users can connect to the network
without being physically restricted to a specific location. They are commonly
employed in homes, offices, public spaces, and educational institutions. WLANs
rely on access points acting as wireless routers to transmit and receive data
wirelessly.
Wide Area Network (WAN):
A Wide Area Network (WAN) covers a broad geographic area and interconnects
multiple LANs or networks. WANs are commonly used to establish connectivity
between different locations, such as branch offices or networks belonging to
various organizations. To transmit data across long distances, WANs utilize
public or private telecommunication infrastructures like leased lines, MPLS
(Multiprotocol Label Switching), or the internet. WANs offer long-distance
communication capabilities, but their data transfer rates are generally slower
than those of LANs.
Storage Area Network (SAN):
A Storage Area Network (SAN) is a specialized network architecture that
enables high-speed access to consolidated block-level storage resources. SANs
are commonly used in data centres and enterprise environments to efficiently
connect multiple servers to shared storage devices. They facilitate centralized
storage management, data backup, and data replication. SANs often utilize
high-speed fiber channel or iSCSI protocols for seamless storage connectivity.
,Intranet:
An intranet is a private network that utilizes internet technologies to facilitate
information sharing, resource access, and collaboration within an organization.
It operates within the organization's boundaries and is accessible only to
authorized users. Intranets play a crucial role in internal communication,
document sharing, knowledge management, and the dissemination of
corporate information. They often feature web-based interfaces for accessing
internal services, such as employee portals, company-wide announcements,
and shared documents.
Extranet:
An extranet expands on the functionality of an intranet by granting controlled
access to external users, including partners, suppliers, or customers. It provides
a secure and regulated environment for collaboration and information
exchange with trusted external entities. Extranets enable businesses to share
specific resources or collaborate on projects while maintaining the privacy and
security of their internal networks.
Internet:
The internet is a vast global network consisting of interconnected networks
spanning the entire world. It enables communication and data exchange
among millions of devices worldwide. Using standardized protocols, primarily
the Internet Protocol (IP), the internet facilitates the transmission of data
across diverse systems. It provides access to a wide range of services,
information resources, and online applications, such as email, web browsing,
social media, and cloud services. The internet has become an indispensable
part of modern communication, playing a pivotal role in connecting people and
businesses globally.
Cloud Computing:
Cloud computing refers to the delivery of computing services, such as servers,
storage, databases, software, and networking, over the internet. Cloud
networks offer on-demand access to scalable and virtualized resources,
reducing the need for organizations to maintain their physical infrastructure.
Cloud computing provides flexibility, cost-effectiveness, and simplified
management, enabling businesses to scale their resources up or down based
on demand. Users can access cloud services from anywhere with an internet
,connection, empowering remote work, data backup, and disaster recovery
capabilities.
Wired and Wireless Integration:
The integration of wired and wireless networks enables devices to seamlessly
connect using both wired and wireless technologies. This integration provides
users with flexibility and mobility, allowing them to switch between wired
connections, like Ethernet, and wireless connections, such as Wi-Fi, based on
their requirements and availability. Wired connections offer higher bandwidth,
lower latency, and increased reliability, making them suitable for applications
that demand consistent performance. Wireless connections offer mobility and
convenience, enabling users to access the network without physical limitations.
Wired and wireless integration is particularly advantageous in environments
where a combination of stationary and mobile devices coexist, such as offices,
educational institutions, and public spaces.
Physical Topologies
Physical topologies refer to the physical arrangement and connection of
network devices. Common physical topologies include:
Star Topology:
In a star topology, devices are connected to a central hub or switch. All
communication flows through the central device, simplifying network
management and allowing for easy addition or removal of devices. The star
topology has several advantages. Firstly, it is highly reliable as the failure of one
cable or device does not affect the functionality of other devices in the
network. It also ensures high performance by eliminating data collisions.
Additionally, connecting or removing devices does not cause disruptions to the
network. Each device only needs one port to connect to the hub, making it
straightforward to set up. However, there are a few disadvantages to consider.
Star topology requires more cable compared to a linear bus topology. If the
connecting network device, such as a network switch, fails, the nodes attached
to it are disabled and cannot participate in network communication.
Furthermore, if the central hub fails, all devices connected to it become
inoperable.
, Extended Star Topology:
An extended star topology connects multiple star networks together using a
central switch or hub. This topology provides scalability by allowing the
addition of new networks. Extended star topology offers several advantages
over other network topologies. Firstly, it provides better performance
compared to bus topology as there is no unnecessary transmission of messages
in the network. Messages are only transferred between the source node,
central hub, and destination node, minimizing network traffic. In the event of a
node failure, the entire network does not go down, ensuring higher network
reliability. The topology enables easy addition and removal of nodes,
simplifying network management. However, extended star topology has a few
disadvantages. Since all nodes are connected to the central hub, it requires
more cables at each node, leading to increased setup costs compared to bus or
ring networks. If the central hub experiences a failure, the entire network can
go down, resulting in network-wide disruption.
