This document discusses various networking devices used to connect electronic devices and share resources in a computer network. It describes network interface cards (NICs) that provide the physical interface between a computer and cabling. It also covers repeaters that regenerate signals to extend distances, modems that modulate and demodulate signals for internet connections, hubs and switches that connect multiple devices either by broadcasting or selectively forwarding, bridges that segment networks while filtering traffic, and routers that intelligently connect different network types and choose optimal paths between them. The document provides details on the function and layer (physical, data link, network) of operation for each type of networking device.

1. COMPUTER NETWORKING
DEVICES
By Rajesh Sadhukha
Email- rajeshsadhukha@gmail.com

2.  What are Networking Devices ?
• Network devices are components used to connect computers
or other electronic devices together so that they can share
files or resources like printers or fax machines. Devices used
to setup a Local Area Network (LAN) are the most common
type of network devices used by the public. A LAN requires a
hub, switch, router.
• Networking Devices are also called Communicating Devices.

3.  Networking Devices
NIC (Network Interface card)
Repeater
Modem
Bridge
Hub
Switch
Router

4. Connecting Devices
Networking Devices Internetworking
Devices
Repeaters Bridges Routers Gateways

5.  NIC (Network Interface card)
 NIC provides the physical interface
between computer and cabling.
 It prepares data, sends data, and
controls the flow of data. It can also
receive and translate data into bytes for
the CPU to understand.
 It has specific MAC address (48 bit)
 Ethernet is a physical and data link
layer technology for local area
networks (LANs).

6.  Repeater
 Network repeaters regenerate incoming
electrical, wireless or optical signals. With
physical media like Ethernet or Wi-Fi, data
transmissions can only span a limited distance
before the quality of the signal degrades.
Repeaters attempt to preserve signal integrity
and extend the distance over which data can
safely travel.
 Repeaters remove the unwanted noise in an
incoming signal.
 It can’t filter the signal traffic.
 it works in physical layer of OSI Model.

7. Modem
Two Type of Modem
 The word "modem"
comes from "modulator-
demodulator“
 Modulation: digital DSL ADSL
information to analog  Digital Subscriber Line.
signals Asymmetric Digital Subscriber Line.
 Demodulation: analog
signals back into useful
digital information
 An ISP (Internet Service
Provider) is required to
complete a connection to
the Internet.

8. Active (It can amplify the Signal)
Hubs Passive (It can’t)
 There are two types of hubs: active
and passive.
 Passive hubs simply connect all ports
together electrically and are usually
not powered.
 Active hubs use electronics to
amplify and clean up the signal
before it is broadcast to the other
ports.
 Hubs are devices used to link several
computers together.
 They repeat any signal that comes in
on one port and copy it to the other
ports (a process that is also called
broadcasting).
 It works in physical Layer of OSI
Model.

10.  Bridges
 They join similar topologies and are used to divide network
segments.
 It can filter traffic on the basis of MAC address.
 If it is aware of the destination address, it is able to forward
packets; otherwise a bridge will forward the packets to all
segments. They are more intelligent than repeaters but are
unable to move data across multiple networks
simultaneously.
 Unlike repeaters, bridges can filter out noise.
 Works in Data link Layer of OSI Model.
 Multiple collision Domain but single Broadcast Domain.
 The main disadvantage to bridges is that they can’t connect
dissimilar network types or perform intelligent path
selection. For that function, you would need a router.

11. Ports are limited to 16 only. Software specific device.

12.  Switches
 A network switch is a computer networking device that
connects network segments.
 Populates MAC address table on the basis of source MAC
address of a Frame.
 Network switches are capable of inspecting data frames as
they are received, determining the source and destination
device of that frame, and forwarding it appropriately.
 Data Link Layer or Layer 2 Device.
 Multiple collision Domain but single Broadcast Domain.
 A vital difference between a hub and a switch is that all the
nodes connected to a hub share the bandwidth among
themselves, while a device connected to a switch port has
the full bandwidth all to itself.

13.  For example, if 10 nodes are communicating using a hub on a 10-
Mbps network, then each node may only get a portion of the 10
Mbps if other nodes on the hub want to communicate as well.
 But with a switch, each node could possibly communicate at the
full 10 Mbps.

14.  Routers are highly intelligent devices that connect multiple
network types and determine the best path for sending data.
 Routers are normally used to connect one LAN to another.
 These devices examine incoming packets to determine the
destination address of the data. It then examines its internal
routing table to choose the best path for the packet through the
network, and switches them to the proper outgoing port.
 However, they are slower than bridges because they are more
intelligent devices; as such, they analyze every packet, causing
packet-forwarding delays. Because of this intelligence, they are
also more expensive.
 Routers are OSI network layer 3 devices
 Typically, when a WAN is set up, there will be at least two routers
used.

15.  Multiple collision Domain but single Multiple Domain.
 Filter traffic on the basis of IP address.

16. THANK YOU