INTRODUCTION TO SWITCHING
MINAKSHI SHARMA
What is Switching?
Switching refers to the process of
directing data from one device to
another in a network. It ensures data is
efficiently transferred across devices in
a network
Benefits of Switching
•Improved Efficiency: Packet switching allows for better utilization
of bandwidth.
•Scalability: Switching supports a growing number of devices and
users in a network.
•Cost-Effective: Reduces the need for dedicated communication
lines, especially with packet switching.
Types of Switching
Circuit Packet Message
• Dedicated path established for • Data is broken into packets • Entire messages are stored and
the duration of the and routed independently forwarded from one device to
communication (e.g., traditional through the the next.(e.g., Email delivery
telephone systems). network.(e.g.,Internet) systems.).
• Pros: Consistent quality • Pros: Efficient, flexible, and • Pros: Suitable for
and speed for scalable. non-real-time communications.
communication. • Cons: Can result in variable • Cons: Delays can occur due to
• Cons: Inefficient as speed and reliability due to the storage of messages at
resources are unused when congestion. each node.
communication is idle
Circuit Switching HighLights
Packet Switching
Packet Switching has two main techniques:
1. Datagram Packet Switching:
In this technique, each packet is routed independently without a
fixed path. Each packet may take different routes to reach the
destination, and their sequence can change as well.
Features:
•Each packet decides its own route.
•Packets may arrive in a different order.
•It is connectionless, meaning there is no fixed path between
the sender and receiver.
•If there is network congestion or packet loss, packets may
need to be resent.
•Example: Internet (IP), where packets can take different routes to
reach their destination.
2. Virtual Circuit Packet Switching:
In this technique, a virtual circuit (logical path) is established before
data transmission begins, and all packets follow this predefined
path to reach the destination.
Features:
•A logical path is established between the
sender and receiver before data transmission.
•It is connection-oriented, meaning there is a
fixed route for communication.
•If a packet is lost or encounters an error, the
system can automatically resend it.
•Example: X.25 network protocol, which was used
in older communication systems.
Message Switching
Differences
Aspect Circuit Switching Packet Switching Message Switching
Establishes a dedicated path Data is broken into packets Entire message is stored and
Definition
for communication. and routed independently. forwarded at each hop.
Dedicated, constant No dedicated connection; No dedicated connection;
Connection Type
connection. data travels in packets. message is forwarded.
Messages are stored and
Analogous to a phone call – Data is sent in discrete
Communication Type forwarded from node to
fixed connection. packets over varying paths.
node.
Data is transmitted in a Data is sent in packets The whole message is
Data Transmission
continuous stream. which can vary in size. stored and then forwarded.
Aspect Circuit Switching Packet Switching Message Switching
Best for internet
Best for real-time Best for non-time-sensitive
Usage communication (e.g.,
communication (e.g., voice). applications (e.g., emails).
browsing).
Reliability can vary Reliability is lower due to
Very reliable; no interruption
Reliability depending on network delays in storing and
once the path is set.
congestion. forwarding.
Fixed and low delay after Variable delay; depends on High delay due to message
Speed/Delay
connection is established. packet routing. forwarding at each hop.
Wastes resources due to
Wastes resources when the Efficient as resources are
Resource Utilization message storage at each
connection is idle. shared across users.
node.
Highly scalable; easily Not scalable for real-time
Not easily scalable; more
Scalability handles growing number of communications; can cause
users require more lines.
users. bottlenecks.
