IN data communication subject slide

1. Network
connecting device

2. IntroductionNetworking is a form of telecommunication between computers where they
exchange data with a data link. One computer-network everyone is familiar
with is the internet. Computer nodes or hosts are able to excess, create,
delete and alter data that is on this network. If a device can transmit
information to another device, they are considered to be networking.
In this article are talking about the different network devices like;
Hub
Repeater
Switch
Modem
Router

3. 1.HUB
A Ethernet Hub (multi-port repeater) is a small
rectangular electronic network hardware device that
connects many computers and other network devices
to form a single central switching point. Once
connected through the hub, all computers and
network devices communicate with each other. The
number of ports that an Ethernet hub varies from
four and five ports to eight and sixteen ports. Original
Ethernet hubs only offered 10 Mbps speeds, newer
hubs now offer 100 Mbps support which usually offer
both 10 Mbps and 100 Mbps capabilities.

4. Advantages of hubs
Following are the benefits or advantages of
Hubs:
It can extend total distance of the network.➨
It does not affect performance of the➨
network seriously.
It is cheaper.➨
It can connect different media types.➨

5. Disadvantages of hub
Following are the disadvantages of Hubs:
➨It does not have mechanisms such as collision detection and
retransmission of packets.
It does not operate in full duplex mode.➨
It can not connect different network architectures such as➨
token ring and Ethernet etc.
It can not filter information i.e. it passes packets to all the➨
connected segments.
It does not have mechanism to reduce the network traffic.➨

6. 2.Repeater
Network device used to regenerate or replicate
a signal. Repeaters are used in transmission
systems to regenerate analog or digital signals
distorted by transmission loss. Analog repeaters
frequently can only amplify the signal while
digital repeaters can reconstruct a signal to near
its original quality.
In a data network, a repeater can relay messages
between sub networks that
different protocols or cable types.

7. Advantages of repeater
Repeaters can extend a network total
distance
Repeaters do not seriously affect network
performance
Certain repeaters can connect networks
using different physical media.

8. Disadvantages of repeater
Repeaters cannot connect different network architectures.
Repeaters do not reduce network traffic.
The number of repeaters must be limited.
Repeaters do not segment the network.
Too many repeaters on a network create noise on the wire
and increase the likelihood of packet collisions.
Devices that are separated only by a repeater are part of
the same collision domain.

9. 3.Switches
A network switch is a multiport network bridge that uses hardware
addresses to process and forward data at the data link layer(layer 2) of
the OSI model. Some switches can also process data at the network
layer (layer 3) by additionally incorporating routing functionality. Such
switches are commonly known as layer-3 switches or multilayer
switches.
Switches for Ethernet are the most common form of network switch.
The first Ethernet switch was introduced by Kalpana in 1990.Switches
also exist for other types of networks including Fiber
Channel, Asynchronous Transfer Mode, and InfiniBand.

10. Advantages of switches
Switches increase available network bandwidth
Switches reduce the workload on individual
computers
Switches increase network performance
Networks that include switches experience
fewer frame collisions because switches create
collision domains for each connection (a process
called micro segmentation)
Switches connect directly to workstations.

11. Disadvantages of switches
They are significantly more expensive then
bridges.
Network connectivity can be difficult to trace
through a switch.
Broadcast traffic may be troublesome on a
switches.

12. 4.Modem
A modem is a hardware device that converts data
between transmission media so that it can be transmitted from
computer to computer . The goal is to produce a signal that can
be transmitted easily and decoded to reproduce the original
digital data. Modems can be used with any means of
transmitting analog signals from light-emitting diodes to radio.
A common type of modem is one that turns the digital data of
a computer into modulated electrical signal for transmission
over telephone lines and demodulated by another modem at
the receiver side to recover the digital data.

13. Advantages of modems
It convert digital signal to analog
signal.
Modem is not expensive.
Higher transmission speed.

14. Disadvantages of modems
External modem do not allow you to
mobility with laptop but it does provide
faster connection and less power taker.
Internal modem allow you mobility to use
wireless internet at hot spot but
connection is slower and power uptake
greater.

15. 5.Router
A router is a networking device that forwards data
packets between computer networks. Routers perform
the traffic directing functions on the Internet. Data sent
through the internet, such as a web page or email, is in
the form of data packets. A packet is typically forwarded
from one router to another router through the networks
that constitute an internetwork until it reaches its
destination node.
A router is connected to two or more data lines from
different networks. When a data packet comes in on one
of the lines, the router reads the network address
information in the packet to determine the ultimate
destination. Then, using information in its routing
table or routing policy, it directs the packet to the next
network on its journey.

16. Advantages of router
Routers can connect different network architectures,
such as Ethernet and Token Ring.
Router can choose the best path across an internetwork
using dynamic routing techniques.
Routers reduce network traffic by creating collision
domains.
Routers reduce network traffic by creating broadcast
domains.

17. Disadvantages of router
They operate based on routable network protocols.
They are expensive compare to other network devices.➨
Dynamic router communications can cause additional network➨
overhead. This results into less bandwidth for user data.
They are slower as they need to analyze data from layer-1 through➨
layer-3.
They require considerable amount of initial configurations.➨
They are protocol dependent devices which must understand the➨
protocol they are forwarding.

18. Thank you
any question?