Page 27 - CITS - Computer Software Application -TT

COMPUTER SOFTWARE APPLICATION - CITS

• Inefficiency: Circuit switching is less efficient for data communication compared to packet switching because
the dedicated circuit is reserved even when there is silence or no data transmission. This inefficiency makes it
less suitable for data services like internet browsing.
• Scalability Challenges: Circuit switching can be challenging to scale as the number of users and communication
sessions grows. It requires significant infrastructure to maintain dedicated circuits for all potential connections.

• Robustness: Circuit-switched networks are generally robust and provide high call quality since the dedicated
circuit ensures a constant, reliable connection.
Message Switching:

Message switching is a method of data communication where complete messages or data units are transmitted
as a whole from the source to the destination. Unlike packet switching, which breaks data into smaller packets
for transmission, message switching sends entire messages from one point to another. Here are some key
characteristics of message switching:
• Whole Message Transmission: In message switching, the entire message is sent as a single unit. This
message could be a text message, a file, or any other data unit.
• Store-and-Forward: Message switching typically involves a store-and-forward mechanism. The message is
received at an intermediate node (message switch) and stored temporarily before being forwarded to the next
hop. This intermediate storage allows for some degree of buffering and error handling.
• Connectionless: Message switching is connectionless, meaning that there is no dedicated or established
path between the sender and receiver before sending the message. Each message is handled individually and
can take different routes to reach its destination.

• Variable Delivery Times: Since messages can take different paths and may be temporarily stored at
intermediate nodes, delivery times for messages in message switching networks can vary. Some messages
may be delivered quickly, while others may experience delays.

• Less Efficient: Message switching is generally less efficient than packet switching, especially when it comes
to utilizing network resources. This is because it sends entire messages even if they are relatively small,
leading to less efficient use of bandwidth.
• Historical Significance: Message switching was one of the earliest forms of data communication used in
telegraph and telex systems. It predates modern computer networking technologies like packet switching and
was prevalent during the early days of long-distance communication.
Packet Switching:
Packet Switching, on the other hand, is a more efficient and flexible method of communication commonly used in
modern computer networks, including the Internet.
Data is divided into smaller packets, each containing a portion of the data, together with source and destination
addresses.

These packets are then individually routed through the network based on the current network conditions and
available routes.
This allows for more efficient use of network resources, as different packets can take different routes and be
interleaved over the same communication lines. Packet switching also permits multiple conversations (sessions)
to share the same physical network infrastructure simultaneously.
Key characteristics of packet switching include:
• Dividing Data: When data is sent across a network using packet switching, it is broken down into small
packets. These packets are typically a few hundred bytes in size.

• Routing: Each packet is treated independently and can take a different route to reach its destination. Routers
and switches within the network make decisions about how to forward each packet based on its destination
address.
• Efficiency: Packet switching is efficient because it allows multiple devices to share a network’s resources
simultaneously. It avoids the need for dedicated communication paths between sender and receiver, as is the
case in circuit switching.

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CITS : IT&ITES - Computer Software Application - Lesson 01-17