This document defines and describes several types of communication networks and networking devices. It discusses simplex, half-duplex, and full-duplex communication, as well as examples like broadcasts, CB radios, and telephone networks. It also defines local area networks (LANs), metropolitan area networks (MANs), wide area networks (WANs), and the internet. Additionally, it provides descriptions of common networking devices like hubs, switches, routers, and their functions. Finally, it briefly discusses network addressing at the network layer.

1. Assignment on
Course title:Data communication
Course code: 313
Submitted to Submitted by
Pranab Bandhu Nath Fatema Yesmin Aka
Lecturer of CSE ID: 1834902155
City university Sec: 49th (B)

2. Simplex
• Simplex is a type of communication in which data can
only be transmitted in one direction. It is often used in
contrast to duplex communication, in which data can
flow bidirectionally (back and forth) between two
devices.
• Broadcasts, in which a single transmission is sent to
many users, is a common type of simplex
communication. For instance, radio broadcasts,
television broadcasts, and Internet streaming are all
examples of simplex transmissions. Since these mediums
only need to transmit, rather than receive data, simplex
communication is all that is necessary.

3. Half-Duplex
• Half-duplex is a type of communication in which data can flow
back and forth between two devices, but not simultaneously.
Each device in a half-duplex system can send and receive
data, but only one device can transmit at a time.
• An example of a half-duplex device is a CB (citizens band)
radio. The CB protocol, which is used by truckers, police
officers, and other mobile personnel, allows users to
communicate back and forth on a specific radio frequency.
However, since the CB protocol only supports half-duplex
communication, only person can speak at a time. This is why
people communicating over two-way radios often say "over"
at the end of each statement. It is a simple way of telling the
recipient he or she can respond if necessary.

4. Full-duplex
• Full-duplex, or simply "duplex," is a type of
communication in which data can flow two ways at the
same time. Full duplex devices, therefore, can
communicate back and forth simultaneously.
• Telephones are common examples of full-duplex devices.
They allow both people to hear each other at the same
time. In the computer world, most network protocols are
duplex, enabling hardware devices to send data back and
forth simultaneously. For example, two computers
connected via an Ethernet cable can send and receive
data at the same time. Wireless networks also support
full-duplex communication. Additionally, modern I/O
standards, such as USB and Thunderbolt, are full-duplex.

5. Internet
• The internet is a globally connected network
system facilitating worldwide communication
and access to data resources through a vast
collection of private, public, business,
academic and government networks. It is
governed by agencies like the Internet
Assigned Numbers Authority (or IANA) that
establish universal protocols.

6. Intranet
• An intranet is a secure and private enterprise
network that shares data o application resources
via Internet Protocol (IP). An Intranet differs from
the internet, which is a public network.
• Intranet, which refers to an enterprise’s internal
website or partial IT infrastructure, may host
more than one private website and is a critical
component for internal communication and
collaboration.

7. Local Area Network (LAN)
• A local area network (LAN) is a group of
computers and peripheral devices that share a
common communications line or wireless link to
a server within a distinct geographic area. A local
area network may serve as few as two or three
users in a home office or thousands of users in a
corporation's central office. Homeowners and
information technology (IT) administrators set up
LANs so that network nodes can communicate
and share resources such as printers or network
storage.

8. Metropolitan Area Network (MAN)
• A metropolitan area network (MAN) is similar
to a local area network (LAN) but spans an
entire city or campus, or some other
municipal or organizational territory. MANs
are formed by connecting multiple LANs.
Thus, MANs are larger than LANs, but smaller
than wide area networks (WAN) that cover
dispersed geographical areas, sometimes
directly connecting users around the world.

9. Wide Area Network ( WAN),
• A wide area network (also known as WAN), is
a large network of information that is not tied
to a single location. WANs can facilitate
communication, the sharing of information
and much more between devices from around
the world through a WAN provider.

10. HUB
• A hub, in the context of networking, is a
hardware device that relays communication
data. A hub sends data packets (frames) to all
devices on a network, regardless of any MAC
addresses contained in the data packet.

11. Switch
• A switch in an Ethernet-based LAN reads incoming TCP/IP
data packets/frames containing destination information as
they pass into one or more input ports. The destination
information in the packets is used to determine which
output ports will be used to send the data on to its intended
destination. Again, the thing to remember is that the switch
is operating at the data link layer, layer 2, sending a frame
that contains a single data packet.
• Switches are similar to hubs, only smarter. A hub simply
connects all the nodes on the network – without switching,
communication happens in a haphazard manner, with any
device trying to communicate at any given time, resulting in
many collisions. A switch, on the other hand, creates an
electronic tunnel between source and destination ports for a
split second, that no other traffic can enter. This results in
communication without collisions.

12. Router
• A router is a device that analyzes the contents
of data packets transmitted within a network
or to another network. Routers determine
whether the source and destination are on the
same network or whether data must be
transferred from one network type to another,
which requires encapsulating the data packet
with routing protocol header information for
the new network type.

13. Network Addressing
• Network Addressing is one of the major responsibilities of
the network layer.
• Network addresses are always logical, i.e., software-based
addresses.
• A host is also known as end system that has one link to the
network. The boundary between the host and link is known
as an interface. Therefore, the host can have only one
interface.
• A router is different from the host in that it has two or more
links that connect to it. When a router forwards the
datagram, then it forwards the packet to one of the links. The
boundary between the router and link is known as an
interface, and the router can have multiple interfaces, one
for each of its links. Each interface is capable of sending and
receiving the IP packets, so IP requires each interface to have
an address.

14. Reference
https://techterms.com/definition/simplex
https://techterms.com/definition/half-duplex
https://techterms.com/definition/full-duplex
https://www.techopedia.com/definition/2419/internet
https://techopedia.com/definition/2433/intranet
https://www.techopedia.com/definition/26350/hub-
networking
https://en.wikipedia.org/wiki/Network_switch
https://www.techopedia.com/definition/2277/router
https://www.techopedia.com/definition/8238/metropolit
an-area-network-man
https://www.comptia.org/content/guides/what-is-a-
wide-area-network
https://www.javatpoint.com/network-addressing