Modem

Modem stands for Modulator/Demodulator. The modem is defined as a networking device that is
used to connect devices connected in the network to the internet. The main function of a modem
is to convert the analog signals that come from telephone wire into a digital form. In digital form,
these converted signals are stored in the form of 0s and 1s. The modem can perform both the task
of modulation and demodulation simultaneously. Modems are majorly used to transfer digital
data in personal systems. The modem is also known as a signal translator as it translates one
signal into another signal by modulating the digital signal into an analog signal for transmission
and then demodulates receiving analog signals into digital signals.

Features of Modem

• Modems can modulate as well as demodulate the signals simultaneously.

• Modem allows to connect only a specific number of devices to the internet.

• According to the features of modem, it's price ranges.

• Modems can be upgraded with the help of a specific software patch.

• To use the devices over the internet with a modem devices need to be configured with
an Internet Service Provider(ISP).

• When the modem is connected to Hub it slows down its process.

Working of Modem

The two main components of a modem are modulation and demodulation. Where the modem can
perform both tasks simultaneously. The step-by-step working of the modem is given below:

Step 1: Data Generation: When data needs to be transmitted it is first generated. Therefore
computer system generated the data which is in digital form of 0s and 1s.
Step 2: Modulation: Modulation is defined as a process of converting digital data signals of the
computer into analog data signals so that these signals can travel on the internet. The digital data
is encoded onto a carrier wave.

Step 3: Transmission: The resultant of modulation that is modulated data is transmitted over the
communication line to the modem that is receiving it.

Step 4: Demodulation: Demodulation is defined as a process in which analog data signals from
the internet are converted into digital data signals so they can be understood by computer
systems. In the process of demodulation the digital data from the carrier wave is decoded.

Step 5: Decoding: The resultant of demodulation that is demodulated data is being sent to the
computer systems for their further use.

Types of Modem

There are different types of modems available. Each modem has different features and provides
with different benefits. Below are the different types of modems:

1. Optical Modem

In modem, different type of media is used to transfer the signals. Optical Modem is the type of
modem that makes use of optical cables instead of using another metallic type of media. The
digital data is converted into the pulse of light that is transmitted on the optical fiber used in the
optical Modem.

2. Digital Modem

Digital Modem is defined as a type of modem that is used to convert digital data into digital
signals. Digital data is in form of 0s and 1s. For this, it performs the process of modulation.
Digital Modem modulates the digital data on digital carrier signals for transmission.

3. Cable Modem

Cable modems are defined as a type of modem used to establish a communication between
computer systems and the Internet Service Providers. A cable modem helps to access high-speed
data through cable TV networks. Such modems are usually connected to desktops or systems and
work like external devices.

4. Satellite Modem

Satellite Modems are defined as a type of modem that provides with the internet connection
through satellite dishes. This type of modem works by sending the input bits into output radio
signals and vice versa. The internet network that is provided by such types of modems is more
reliable and efficient as compared to other types of modems.
5. Dial Modem

A Dial Modem is a type of modem that converts data used in telephone and data used on
computers. In short dial modem converts between analog form and digital form. The networking
devices connected to the computer are all at one end and the telephone line is at another end.
This type of modem transmits the data at a speed of 56000 per/sec.

Advantages of Modem

• A modem converts digital signals into an analog signal.

• The cost of a modem increases according to the features it has.

• The modem helps to connect the LAN to the internet.

• Modem performs both modulation and demodulation processes simultaneously

Disadvantages of Modem

• The working of the modem slows down when connected to the hub.

• The modem cannot track the traffic between the LAN and the internet.

• When using a modem a limited number of network devices can be connected to the
internet.

• Modems have a high rock of security-related attacks.

• The modem does not provide maintenance of traffic.

Gateways
A gateway is a network connectivity device that connects two different configuration networks.
Gateways are also known as protocol converters, because they play an important role in
converting protocols supported by traffic on different networks. As a result, it allows smooth
communication between two networks. It works as the entry-exit point for a network because all
traffic that passes across the networks must pass through the gateway. A gateway monitors and
controls all the incoming and outgoing network traffic. Gateways are also known as protocol
converters In this article, we are going to discuss all important points related to Gateways.

Features of Gateways

Gateways provide a wide variety of features. Some of these are:

• A gateway is situated at a network edge and manages all data that enters or exits the
network.
 • A gateway is distinct from other network devices in that it can operate at any layer of
the OSI model.

• Gateways made the transmission more feasible as it queued up all the data and divided it
into small packets of data rather than sending it bulk.

• Gateways provide security within the network.

Types of Gateways

These below are the types of Gateway on the basis of direction of flow of data:

• Unidirectional Gateways: Data can only pass through unidirectional gateways in one
direction. The destination node replicates changes made in the source node but not the
other way around. They are tools for archiving the packets.

• Bidirectional Gateway: Data can pass through bidirectional gateways in both directions.
They are tools for synchronisation.

These below are the types of Gateway on the basis of functionality of Gateway:

• Network Gateway: The most popular kind of gateway, known as a network gateway acts
as an interface between two disparate networks using distinct protocols. Anytime the
word gateway is used without a type designation, it refers to a network gateway.

• Cloud Storage Gateway: A network node or server known as a cloud storage gateway
translates storage requests made using various cloud storage service API calls, such
as SOAP (Simple Object Access Protocol) or REST (Representational State Transfer).
Data communication is made simpler since it makes it easier to integrate private cloud
storage into applications without first moving those programmes to a public cloud.

• Internet-To-Orbit Gateway (I2O): Project HERMES and Global Educational Network

for Satellite Operations (GENSO) are two well-known I2O gateways that connect devices
on the Internet to satellites and spacecraft orbiting the earth.

• IoT Gateway: Before delivering sensor data to the cloud network, IoT
gateways assimilate it from Internet of Things (IoT) devices in the field and translate
between sensor protocols. They link user applications, cloud networks, and IoT devices.

• VoIP Trunk Gateway: By using a VoIP (voice over Internet Protocol) network, it makes
data transmission between POTS (plain old telephone service) devices like landlines and
fax machines easier.

How Gateways Work?

• The gateway receives data from devices within the network.

 • After receiving data the gateway intercept and analyze data packets, which include
analyzing packet header, payload etc.

• Based on the analysis of the data packets, the gateway calculate an appropriate
destination address of data packet. It then routes the data packets to their destination
address.

• In some cases, the gateway might also want to transform the format of the obtained data
to ensure compatibility at the receiver.

• Once the data packets have been analyzed, routed, and converted, then the gateway sends
the last packets to their respective destinations address inside the network.

Gateways

Advantages of Gateways

• Gateway helps in connecting two different network.

• Gateway is used to filters and does not allow anything that can harm to the network.

• Gateway is worked as the protocol converter.

• Gateway is the highly secure device that provides security from external attacks.

Limitations of Gateways

There are few limitations of gateways as well. Here are some of them:
 • Gateway causes time delay since the conversion of data according to the network requires
time.

• Failure of the gateway might lead to the failure of connection with other networks.

• The implementation of Gateway is very complex and it is not cost efficient.

Routers
A Router is a networking device that forwards data packets between computer networks. One or
more packet-switched networks or subnetworks can be connected using a router. By sending data
packets to their intended IP addresses, it manages traffic between different networks and permits
several devices to share an Internet connection.

Let us understand this by a very general example, suppose you search for www.google.com in
your web browser then this will be a request that will be sent from your system to Google`s
server to serve that webpage, now your request which is nothing but a stream of packets don`t
just go to the google`s server straightaway they go through a series of networking devices known
as a router which accepts this packets and forwards them to correct path and hence it reaches to
the destination server. A router has several interfaces by which it can connect to several host
systems. Routers are the devices that are operated on the Network Layer of the OSI Model, these
are the most common devices used in networking.

Router

How Does Router Work?

• A router determines a packet's future path by examining the destination IP address of the
header and comparing it to the routing database. The list of routing tables outlines how to
send the data to a specific network location. They use a set of rules to determine the most
effective way to transmit the data to the specified IP address.

• To enable communication between other devices and the internet, routers utilize a
modem, such as a cable, fiber, or DSL modem. Most routers include many ports that can
 connect a variety of devices to the internet simultaneously. In order to decide where to
deliver data and where traffic is coming from, it needs routing tables.

• A routing table primarily specifies the router's default path. As a result, it might not
determine the optimum path to forward the data for a particular packet. For instance, the
office router directs all networks to its internet service provider through a single default
channel.

• Static and dynamic tables come in two varieties in the router. The dynamic routing tables
are automatically updated by dynamic routers based on network activity, whereas
the static routing tables are configured manually.

Router Network

Types of Router

There are several types of routers. Some of them are mentioned below:

1. Broadband Routers: These are one of the important kinds of routers. It is used to do
different types of things. it is used to connect computers or it is also used to connect to
the internet.
 2. Wireless routers: These routers are used to create a wireless signal in your office or
home.

3. Wired Routers: Wired Router is used to connects multiple wired devices using a
Ethernet cable, It takes the transmission data from the modem and distribute it to a further
network, it is widely used in schools and small offices.

4. Edge Routers: As the name indicates, these are located at the edges usually connected to
an Internet Service Provider, and distribute packets across multiple packets.

5. Core Routers: Core routers distribute packets within the same network. The main task is
to carry heavy data transfers.

6. Virtual Router: They are implemented using a software on the virtual machine , and
they are more flexible and scalable.

7. Portable Routers: They are used to create private Wi-Fi and hence designed for easy
portability.

Functions of Router

The router performs below major functions:

1. Forwarding: The router receives the packets from its input ports, checks its header,
performs some basic functions like checking checksum, and then looks up to the routing
table to find the appropriate output port to dump the packets onto, and forwards the
packets onto that output port.

2. Routing: Routing is the process by which the router ascertains what is the best path for
the packet to reach the destination, It maintains a routing table that is made using
different algorithms by the router only.

3. Network Address Translation (NAT): Routers use NAT to translate between different
IP address ranges. This allows devices on a private network to access the internet using a
single public IP address.

4. Security: Routers can be configured with firewalls and other security features to protect
the network from unauthorized access, malware, and other threats.

5. Quality of Service (QoS): Routers can prioritize network traffic based on the type of
data being transmitted. This ensures that critical applications and services receive
adequate bandwidth and are not affected by lower-priority traffic.

6. Virtual Private Network (VPN) connectivity: Routers can be configured to allow

remote users to connect securely to the network using a VPN.
 7. Bandwidth management: Routers can be used to manage network bandwidth by
controlling the amount of data that is allowed to flow through the network. This can
prevent network congestion and ensure that critical applications and services receive
adequate bandwidth.

8. Monitoring and diagnostics: Routers can be configured to monitor network traffic and
provide diagnostics information in the event of network failures or other issues. This
allows network administrators to quickly identify and resolve problems.

Architecture of Router

A generic router consists of the following components:

1. Input Port: This is the interface by which packets are admitted into the router, it
performs several key functions as terminating the physical link at the router, this is done
by the leftmost part in the below diagram, and the middle part does the work of
interoperating with the link-layer like decapsulation, in the last part of the input port the
forwarding table is looked up and is used to determine the appropriate output port based
on the destination address.

2. Switching Fabric: This is the heart of the Router, It connects the input ports with the
output ports. It is kind of a network inside a networking device. The switching fabric can
be implemented in several ways some of the prominent ones are:

• Switching via memory: In this, we have a processor which copies the packet
from input ports and sends it to the appropriate output port. It works as a
traditional CPU with input and output ports acting as input and output devices.

• Switching via bus: In this implementation, we have a bus that connects all the
input ports to all the output ports. On receiving a packet and determining which
output port it must be delivered to, the input port puts a particular token on the
packet and transfers it to the bus. All output ports can see the packets but they will
be delivered to the output port whose token has been put in, the token is then
scraped off by that output port and the packet is forwarded

• Switching via interconnection network: This is a more sophisticated network,

here instead of a single bus we use a 2N bus to connect n input ports to n output
ports.

3. Output Port: This is the segment from which packets are transmitted out of the router.
The output port looks at its queuing buffers (when more than one packets have to be
transmitted through the same output port queuing buffers are formed) and takes packets,
does link layer functions, and finally transmits the packets to an outgoing link.
 4. Routing Processor: It executes the routing protocols, and it works like a traditional
CPU. It employs various routing algorithms like the link-state algorithm, distance-vector
algorithm, etc. to prepare the forwarding table, which is looked up to determine the route
and the output port.

Architecture of Router

Security Challenges in Router

There are several challenges faced by the router, due to which an unauthorized access is taken by
another party. Here below are some security challenges in router:

1. Vulnerability Exploits

Firmware is automatically installed on all hardware-based routers to assist the operation of the
router. Like any other programme, router firmware frequently has flaws that hackers could use
against it. Vendors of routers usually release updates to fix these flaws. Router firmware needs to
be updated on a frequent basis as a result. Attackers have the ability to monitor traffic on
unpatched routers and utilise them as part of a botnet.

2. DDoS Attacks

Distributed Denial-Of-Service (DDoS) attacks against network infrastructure frequently target

both large and small organisations. Network outages can be caused by unmitigated network layer
DDoS attacks, which can overload routers or bring them down. Using Cloudflare Magic Transit
is one way to defend networks and routers against DDoS attacks of this nature.

3. Administration Credentials

To carry out administration tasks, a set of admin credentials is included with every router. The
default values for these credentials are "admin" for the username and "admin" for the password.
As soon as possible, change the username and password to something more secure since, if they
are not changed, attackers can use them to remotely take over the router. They are aware of the
typical default values for these credentials.

Advantages of Router

• Easier Connection: Sharing a single network connection among numerous machines is

the main advantage of router. This enables numerous people to connect to the internet,
boosting total productivity. In addition, routers have connections between various media
and network designs.

• Security: Undoubtedly, installing a router is the first step in securing a network

connection. Because using a modem to connect directly to the internet exposes your
computer to several security risks. So that the environment is somewhat secure, routers
can be utilized as an intermediary between two networks. While not a firewall or
antivirus replacement.

• NAT Usage: Routers use Network Address Translation (NAT) to map multiple private IP
addresses into one public IP address. This allows for a better Internet connection and
information flow between all devices connected to the network.

• Supports Dynamic Routing: The router employs dynamic routing strategies to aid in
network communication. The internet work’s optimum path is chosen through dynamic
routing. Additionally, it creates collision and broadcast domains. Overall, this can lessen
network traffic.

• Filtering of Packets: Switching between packets and filtering packets are two more
router services. A collection of filtering rules are used by routers to filter the network. The
packets are either allowed or passed through.

Disadvantages of Router

• Slower: Routers analyze multiple layers of information, from the physical layer to
the network layer, which slows down connections. The same issue can also be
encountered when multiple devices are connected to these network devices, causing
“connection waiting”.

• High Cost: They are more expensive than some other tools for systems administration.
This includes security, extension, and the focal point. As a result, routers are typically not
the greatest option for issues.

• Need for configuration: The router must be properly configured to work properly. In
general, the more complex the intended use, the more configuration is required. This
requires professional installation, which can add to the cost of buying a router.
 • Quality Issues: The time transitions are not always accurate. Even yet, some modern
devices use the 2.4GHz band, which is frequently deactivated. These kinds of separations
are frequently possible for those who live in apartments and condominiums.

• Bandwidth shortages: Dynamic routing techniques used by routers to support

connections tend to cause network overhead, consuming a lot of bandwidth. This leads to
a bandwidth shortage that significantly slows down the internet connection between
connected devices.

Applications of Router

There are several applications of router because nowadays routers are widely used in most of the
networking communication for better communication:

• Hardware equipment, such as servers from BSC, MGW, IN, SGSN, and other remote
location networks, is connected to these networks via routers.

• It is utilised in both wired and wireless communication since it supports a high speed of
data transmission due to its utilisation of STM connections for connectivity.

• Routers are frequently used by internet service providers to transfer data, such as audio,
video, image, and email, from one location to another. Additionally, it can transmit data
globally by utilising the destination's IP address.

• Routers provide access control. It can be set up so that some users can access all of the
data while others can access just a subset of it.

Routing Protocol

The router can recognise other routers on the network and decide on a dynamic basis where to
deliver all network messages through the routing protocol. Several protocols exist, some of
which are listed below:

• Open Shortest Path First: As packets travel across several networks, it is utilised to
determine the optimal path for them to take in order to arrive at their destination.

• Border Gateway Protocol (BGP): It facilitates information sharing between edge

routers to control internet packet routing. For routers, it offers network stability. It can
easily switch to another network connection to transfer the packets.

• Interior Gateway Routing Protocol (IGRP) : IGRP outlines the protocol for
exchanging routing data between gateways inside the separate networks. The routing
information can then be used by the other network protocols to decide how data packets
should be routed.
 • Enhanced Interior Gateway Routing Protocol (EIGRP): This protocol requests a
router to route its neighbours if it cannot find a path to a destination from the routing
tables. The neighbours then forward the request to further neighbours until a router finds
the path.

• Exterior Gateway Protocol (EGP): It is also frequently used for the communication of
routing table data between internet hosts.

Bridge
A bridge in a computer network is a device used to connect multiple LANs together with a larger
Local Area Network (LAN). The mechanism of network aggregation is known as bridging. The
bridge is a physical or hardware device but operates at the OSI model's data link layer and is also
known as a layer of two switches.

The primary responsibility of a switch is to examine the incoming traffic and determine whether
to filter or forward it. Basically, a bridge in computer networks is used to divide network
connections into sections, now each section has a separate bandwidth and a separate collision
domain. Here bridge is used to improve network performance.

Types of Bridges

There are three types of bridges in computer networks, which are as follows:

• Transparent Bridge: Transparent bridges are invisible to other devices on the network.
This bridge doesn't reconfigure the network on the addition or deletion of any station.
The prime function of the transparent bridge is to block or forward the data according to
the MAC address.

• Source Routing Bridge: Source routing bridges were developed and designed by IBM
specifically for token ring networks. The frame's entire route is embedded with the data
frames by the source station to perform the routing operation so that once the frame is
forwarded it must follow a specific defined path/route.
 • Translational Bridge: Translational bridges convert the received data from one
networking system to another. Or it is used to communicate or transmit data between two
different types of networking systems. Like if we are sending data from a token ring to an
Ethernet cable, the translational cable will be used to connect both the networking system
and transmit data.

Working of Bridges

Let's see the step-by-step working of the bridge in computer networks:

• Receiving Data: The bridge gets data packets (or frames) from both network segments A
and B.

• Building a Table: It creates a table of MAC addresses by looking at where the data is
coming from to know which device is on which segment.

• Filtering Data: If the data from network A is meant for a device also on network A, the
bridge stops it from going further.

• Forwarding Data: If the data from network A is meant for a device on network B, the
bridge sends it to the correct place on network B.

• Repeating for Both Sides: The bridge does the same thing for data coming from
network B.
Working of Bridge

Models of Bridge in Computer Networks

There are two main models of bridging in computer network: Local bridging and remote
bridging. Let us learn about them in detail.

• Local Bridging Local bridging connects LAN switches using local cables. This allows
computers on the same Ethernet segment, whether they're connected to virtual hubs or
physical LANs, to communicate freely. It's used when LANs within the same area need to
talk to each other directly at the link layer.

• Remote Bridging Remote bridging connects two bridges over a Wide Area
Network (WAN). This model is used when LANs are located in different geographical
areas and need to communicate with each other at the link layer.

Uses of Bridge in Computer Network

• Bridges are used to increase the network capacity as they can integrate multiple LANs
together.
 • On receiving a data frame, databases use the bridge to decide whether to accept or reject
the data.

• In the OSI model, it can be used to transmit the data to multiple nodes of the network.

• Used to broadcast the data even if the MAC address or destination address is unavailable.

• It forwards data packets despite faulty nodes.

• The data packet can be forwarded or discarded by the bridge when the MAC address is
available.

Functions of Bridges in the Network

• The bridge is used to divide LANs into multiple segments.

• To control the traffic in the network.

• It can interconnect two LANs with a similar protocols.

• It can filter the data based on destination/MAC address.

Advantages

• Bridges can be used as a network extension like they can connect two network topologies
together.

• It has a separate collision domain, which results in increased bandwidth.

• It can create a buffer when different MAC protocols are there for different segments.

• Highly reliable and maintainable. The network can be divided into

multiple LAN segments.

• Simple installation, no requirement of any extra hardware or software except the bridge
itself.

• Protocol transparency is higher as compared to other protocols.

Disadvantages

• Expensive as compared to hubs and repeaters.

• Slow in speed.

• Poor performance as additional processing is required to view the MAC address of the
device on the network.
 • As the traffic received is in bulk or is broadcasted traffic, individual filtering of data is
not possible.

• During the broadcasting of data, the network has high broadcast traffic and broadcast
storms can be formed.

HUB
A hub is a multi-port repeater. A hub connects multiple wires coming from different branches, for
example, the connector in star topology which connects different stations. Hubs cannot filter
data, so data packets are sent to all connected devices. In other words, the collision domain of all
hosts connected through hub remains one. Hub does not have any routing table to store the data
of ports and map destination addresses., the routing table is used to send/broadcast information
across all the ports.

How Does a Network Hub Work?

A hub is a multiport device, which has multiple ports in a device and shares the data to multiple
ports altogether. A hub acts as a dumb switch that does not know, which data needs to be
forwarded where so it broadcasts or sends the data to each port.

Suppose there are five ports in a hub A, B, C, D, and E. Consider A wants to send any data
frame, or let's say A is acting as a sender, so the hub will forward the data transmitted by A to B,
C, D, E. Now, at the same time B also wants to send the data then data received from A and B
will collide and can cause data loss. In this situation, the data gets destroyed, and the hosts send a
jam signal to all the hosts informing them about the collision, and each sender needs to wait for a
certain amount of time.

Note: In the hub, data is sent to all ports but each port accepts only that data whose destination
address matches their MAC address.

Types of Network Hubs

Networks hubs are classified into three types:

1. Active Hub: They have a power supply for regenerating, and amplifying the signals.
When a port sends weak signalled data, the hub regenerates the signal and strengthens it,
then send it further to all other ports. Active hubs are expensive in costs as compared to
passive hubs.

2. Passive Hub: Passive hubs are simply used to connect signals from different network
cables as they do not have any computerised element. They simply connect the wires of
different devices in the star topology. Passive hubs do not do any processing or signal
regeneration and that's why do not require electricity the most they can do is they can
 copy or repeat the signal. It can't clean the message, and it can't amplify or strengthen the
signal.

3. Intelligent Hub: Intelligent hubs as the name suggests are smarter than active and
passive hubs. The intelligent hub comprises a special monitoring unit named
a Management Information Base (MIB). This is software that helps in analysing and
troubleshooting network problems. Intelligent hubs work similarly to active hubs but with
some management features. Like it can monitor the traffic of the network and the
configuration of a port.

Features of Hubs

Hubs are the hardware device that operates in the physical layer of the OSI model.

• It supports half-duplex transmission

• It works with shared bandwidth and broadcasting.

• The hub can provide a high data transmission rate to different devices.

• It can detect collisions in the network and send the jamming signal to each port.

• Hub does not support Virtual LAN(VLAN) and spanning tree protocol.

• It is unable to filter the data and hence transmit or broadcast it to each port.

• It cannot find the best route/ shortest path to send any data, which makes it an inefficient
device.

Difference Between Network Hub And Switch

Hub Switch

It works on the data link layer of the OSI

It works on the physical layer of the OSI model.
model.

It mainly performs broadcasts and

It performs frame flooding, which includes
performs multicast, and unicast whenever
broadcast, multicast and unicast as well.
required.
Hub Switch

The transmission mode is half-duplex. The transmission mode is full-duplex.

It can filter data and send the frame to the

It cannot perform data filtering.
desired destination.

A switch may contain more than one

There is no spanning tree.
spanning tree possible.

It can not store the MAC address of the ports

It can store the data in a routing table and
and the destination address of the frame that
it helps in further sending the data.
arrived.

It is a passive device. It is an active device.

The switch can operate at a speed of 10-

Hub can operate at a speed of 10Mbps.
100Mbps and 1- 10 Gbps.

Does a Network Hub Affect Speed?

Because network hubs are unable to prioritise data between devices, they can have an effect on a
network's speed. As a result, when numerous devices are in use at once, the total network speed
is decreased because all connected devices share the same bandwidth. Communication delays are
further slowed down by the fact that data must be provided to all linked devices even if only one
of them requires it. A network hub rather than a switch may be advantageous for particular
applications, such as gaming or streaming, even though it's not the best option for contemporary
networks.

Does Network Hub Have an IP Address?

Network hubs generally do not have an IP address, as they are designed to be transparent and
forward information between connected devices on the same network. This means that any
device can send data through a hub without communicating directly with the hub itself.
Additionally, a hub is typically unaware of the IP addresses of the devices it connects, making
assigning an address unnecessary.

Advantages of Network Hubs

• It is less expensive.

• It does not impact network performance.

• Hub support different network media.

Disadvantages of Network Hubs

• It cannot find the best/ shortest path of the network.

• No mechanism for traffic detection.

• No mechanism for data filtration.

• Not capable of connecting to different network topologies like token ring, ethernet, etc.

Switch
he Switch is a network device that is used to segment the networks into different subnetworks
called subnets or LAN segments. It is responsible for filtering and forwarding the packets
between LAN segments based on MAC address.

Switches have many ports, and when data arrives at any port, the destination address is examined
first and some checks are also done and then it is processed to the devices. Different types of
communication are supported here like unicast, multicast, and broadcast communication.

Features of Network Switches

• It operates in the Data Link Layer in the OSI Model.

• It performs error checking before forwarding data.

• It transfers the data only to the device that has been addressed.

• It operates in full duplex mode.

• It allocates each LAN segment to a limited bandwidth.

• It uses Unicast (one-to-one), multicast (one-to-many), and broadcast (one-to-all)

transmission modes.
 • Packet-switching techniques are used to transfer data packets from source to destination.

• Switches have a more significant number of ports.

Why Are Network Switches Valuable?

Switches are one of the most important things for transferring information between different
endpoints. Some of the benefits are mentioned below.

• Switches are having full-duplex communication which helps in making effective use of
bandwidth.

• Switches help to provide a wired connection to printers, IoT devices, wireless points, and
many more devices.

• IoT Devices send data through Network Switches that help in making smarter
surroundings with the help of Artificial Intelligence.

• Network Devices are made with the help of Switches that carry a large number of traffic
in telecommunication.

Types of Switches

Switches are mainly classified into the following types that are mentioned below.

• Virtual Switches: Virtual Switches are the switches that are inside Virtual Machine
hosting environments.

• Routing Switches: These are the switches that are used to connect LANs.They also have
the work of performing functions in the Network Layer of the OSI Model.

• Unmanaged Switches: Unmanaged Switches are the devices that are used to enable
Ethernet devices that help in automatic data passing. These are generally used for home
networks and small businesses. In case of the requirement of more switches, we just add
more switches by plug and play method.

• Managed Switches: Managed Switches are switches having more complex networks.
SNMP (Simple Network Management Protocol) can be used for configuring managed
switches. These types of switches are mostly used in large networks having complex
architecture. They provide better security levels and precision control but they are more
costly than Unmanaged switches.

• LAN Switches: LAN (Local Area Network) Switches are also called ethernet switches or
data switches. LAN switches always try to avoid overlapping of data packets in the
network just by allocating bandwidth in such a manner.
 • PoE Switches: Power over Ethernet(PoE) are the switches used in Gigabit Ethernets.
PoE help in combining data and power transmission over the same cable so that it helps
in receiving data and electricity over the same line.

• Smart Switches: Smart Switches are switches having some extra controls on data
transmissions but also have extra limitations over managed Switches. They are also called
partially managed switches.

• Stackable Switches: Stackable switches are connected through a backplane to combine

two logical switches into a single switch.

• Modular Switches: These types of switches help in accommodating two or more cards.
Modular switches help in providing better flexibility.

What is a Layer 2 Switch?

A Layer 2 switch operates at Layer 2 of OSI model, which is the Data Link Layer. The switch
forwards data packets depending on the devices’ MAC (Media Access Control) addresses that are
in its network. Most commonly they are found in Local Area Networks (LAN) where their main
purpose includes providing different collision domains while reducing congestion within that
network .To enable delivery of this data to specific destination layer II switches find out
appropriate port for these packets on MAC basis.

What is a Layer 3 Switch?

A Layer 3 Switch is identical to an ordinary switch in its operation with a router at the same time,
working at both data link layer (Layer 2) and network layer (Layer 3) under the Open Systems
Interconnection model. Layer 3 switches can route packets between diverse subnets or VLANs
(virtual LANs) with the application of IP addresses, similar to the manner in which networking
devices called routers handle them. Hence they are suitable for big-sized networks necessitating
fast switching together with routing abilities.

What is an Unmanaged Switch?

A basic, plug-and-play network device called unmanaged switch permits automatic

communication between Ethernet devices. Where the network design is uncomplicated and there
is no need for intricate settings, unmanaged switches are mostly found in home networks or
small businesses. They do not include any configuration choices or advanced functions thus they
are convenient to install and use.

What is a Managed Switch?

A managed switch has more sophisticated functionalities and elevated authority on network
configurations as opposed to an unmanaged one. They let the net admins set up, manage and
observe their net working so as to enhance its effectiveness and safeguard it against possible
hacks or any other form of interference. Managed switches also provide remote alterations
through SNMP (Simplified Network Management Protocol). Other different protocols such as
VLANs, QoS (Quality of Service), and redundancy alternatives are supported by such switches
too.

How Does a Network Switch Works?

When the source wants to send the data packet to the destination, the packet first enters the
switch and the switch reads its header and finds the MAC address of the destination to identify
the device then it sends the packet out through the appropriate ports that lead to the destination
devices.

Switch establishes a temporary connection between the source and destination for
communication and terminates the connection once the conversation is done. Also, it offers full
bandwidth to network traffic going to and from a device simultaneously to reduce collision.

How Does a Network Switch Works?

Switching Techniques

Switching techniques are used to decide the best route for data transmission between source and
destination. These are classified into three categories :

• Circuit Switching

• Message Switching

• Packet Switching

How To Set Up a Network Switch?

There are different kinds of switches that work according to the tasks defined. For a small
network LAN, or for a home network, a network switch is used by plugging into a port of the
router. Below mentioned are the steps which are used in setting up network switches.

Step 1: Switch has to be bought as per the requirement of the network.

Step 2: The switch port has to be connected directly to the router using the cable. Generally, if
there is an uplink port present in the switch, the wire should be connected to that port, if the
uplink power is not present, then the wire has to be connected to any port of the router.

Step 3: After proper connection, the IP addresses of devices are configured.

Difference Between Network Switch and Router

Network Switch Router

Network Switch works on Layer 2 of the OSI The router is primarily a device of
Model. Layer 3 of the OSI Model.

The resource is shared among multiple devices with Data is moved between two or more
the help of a single LAN using a network switch. computers with the help of a router.

Network switches uses data frames. Routers use data packets.

Router works with both wired and

Switches only work in a Wired network connection.
wifi networks.

Switches use MAC Addresses for transferring data Routers use IP Addresses for the same
to the proper destination. work.

Uses of Network Switches

Network Switches are an important part of Network communication. Some of the use cases are
mentioned below.

• Network switches help provide automatic link connections that remove time-consuming
settings and provide easy access to network devices.

• Switches provide a better, more secure, reliable network having more control over data.

• Generally, switches work in full duplex mode, which helps in continuous data
transmission and that improves better connectivity.

• As MAC Address is used for the devices connected to it, that helps in the delivery of
messages to only the required destination, not everywhere.

• Network Switches work for home networks or local networks where streaming works are
performed regularly.

Difference between Network Switch and Hub

Network Switch Hub

Network Switch is a device of layer 2 of the OSI Hub is a physical device of Layer 1 of
Model. the OSI Model.

Network Switch is a little more complex than a Hub is a simple device as compared to
Hub. Network Switch.

Network Switch easily manages data in and out, Communication Collisions usually
hence less communication collision. happen in a Hub.

Network Switches transfer data together by The main task of Hub is to connect all
connecting devices. nodes of the network.

Switches prevent collision with the help of Ethernet Hubs cannot help in preventing
frames. collisions.

Advantages of Switches

• Prevents traffic overloading in a network by segmenting the network into smaller

subnets.

• Increases the bandwidth of the network.

• Less frame collision as the switch creates the collision domain for each connection.

Disadvantages of Switches

• It can not stop traffic destined for a different LAN segment from traveling to all other
LAN segments.

• Switches are more expensive.