Circuit Switching | Circuit switched network | Switching technology | TechTerms

Summary

This script explains the concept of network communication through circuit switching, comparing it to restaurant reservations to illustrate the reservation of resources. It describes the process involving switches and channels, the use of FDM and TDM for channel creation, and the three phases of circuit-switched network communication: connection setup, data transfer, and teardown. The script highlights the guaranteed constant transmission rate and minimal delay but also points out the inefficiency due to idle resources during non-communication periods.

Takeaways

• 🌐 Networks are formed by connecting two or more devices, allowing for one-to-one communication.
• 🔗 Point-to-point connections can be established using mesh or star topology, but this becomes impractical with more devices.
• 🔄 Switching is introduced as a solution to manage connections efficiently, using devices called switches.
• 🔌 End systems connect directly to switches, which set up temporary point-to-point connections among them.
• 🚀 There are two fundamental approaches to data transfer: circuit switching and packet switching.
• 🍽️ Circuit switching is like making a reservation at a restaurant, where resources are reserved for the session.
• 🏨 Packet switching is like a restaurant without reservations, where resources are not reserved in advance.
• 🔄 In circuit switching, a dedicated transmission rate is guaranteed through reserved channels in the network.
• 📡 Channels in circuit-switched networks are created using Frequency Division Multiplexing (FDM) or Time Division Multiplexing (TDM).
• 📞 Communication in circuit-switched networks involves three phases: connection setup, data transfer, and connection teardown.
• 🚫 Data in circuit-switched networks is transferred as a continuous flow without packets, and addressing is only used in the connection setup phase.
• 🕒 Circuit-switched networks have minimal delay due to pre-established connections but can be inefficient when resources are idle.

Q & A

What is the primary purpose of setting up a network among multiple devices?

The primary purpose of setting up a network among multiple devices is to enable one-to-one communication, allowing devices to connect and exchange information efficiently.

What are the limitations of point-to-point connections in a network with a large number of devices?

Point-to-point connections become impractical in a network with a large number of devices due to the excessive number of connections required, making the network complex and difficult to manage.

What is switching, and how does it address the problem of impracticality in large networks?

Switching is a method where devices called switches are used to set up temporary point-to-point connections among end systems. It addresses the problem of impracticality by reducing the number of connections needed and allowing efficient communication in large networks.

What are the two fundamental approaches to data transfer in a network?

The two fundamental approaches to data transfer in a network are circuit switching and packet switching.

How is circuit switching analogous to restaurant A in the given analogy?

Circuit switching is analogous to restaurant A because, like the restaurant accepting reservations, it reserves resources for the communication session, ensuring a dedicated connection for data transfer.

What is the difference between circuit switching and packet switching in terms of resource allocation?

In circuit switching, resources are reserved for the entire communication session, whereas in packet switching, resources are not reserved, and data is sent in packets that are routed independently.

What is a circuit in the context of circuit-switched networks?

A circuit in the context of circuit-switched networks is a dedicated path established between two endpoints, consisting of a combination of channels in the interconnected links, ensuring a constant transmission rate for data transfer.

How are channels created in a circuit-switched network?

Channels in a circuit-switched network are created using Frequency Division Multiplexing (FDM) or Time Division Multiplexing (TDM), where bandwidth or time slots are reserved for sender-receiver pairs.

What are the three phases of communication in a circuit-switched network?

The three phases of communication in a circuit-switched network are the connection setup phase, the data transfer phase, and the connection teardown phase.

Why are circuit-switched networks considered to have low efficiency?

Circuit-switched networks are considered to have low efficiency because the reserved resources are idle during periods of inactivity, and cannot be used by other communication sessions, leading to underutilization of the network.

What is the primary advantage of circuit-switched networks in terms of delay?

The primary advantage of circuit-switched networks in terms of delay is that it is minimal because there is no waiting at the switches for resources, as the circuit is already set up before data transfer begins.