Answer:

Circuit switching is the method in which the required resources for communication between end systems are reserved for the duration of the session between end systems. In this method, a dedicated communication path is established between the sender and the receiver before any data transmission takes place. The path remains reserved for the entire duration of the session, even if there is no data being transmitted.

Explanation:

Circuit Switching:

Circuit switching is a method of establishing a dedicated communication path between the sender and the receiver. In this method, a virtual circuit is created between the two end systems before any data transmission takes place. The virtual circuit consists of a series of physical links and switches that are reserved exclusively for the session.

Reservation of Resources:

In circuit switching, the required resources for communication are reserved for the duration of the session. These resources include bandwidth, buffers, and routing tables. Bandwidth is reserved to ensure that there is sufficient capacity to transmit the data. Buffers are reserved to temporarily store the data packets during transmission. Routing tables are reserved to determine the path of the virtual circuit.

Advantages of Circuit Switching:

1. Guaranteed Quality of Service: Since the resources are reserved for the entire duration of the session, circuit switching provides a guaranteed quality of service. The dedicated path ensures that there is no congestion or interference from other sessions.

2. Low Latency: Circuit switching provides low latency as the communication path is established before any data transmission takes place. There is no delay in setting up the connection, and the data can be transmitted immediately.

3. Efficient for Continuous Data Streams: Circuit switching is particularly efficient for continuous data streams such as voice and video. The resources are reserved for the entire session, ensuring a continuous and uninterrupted transmission.

Disadvantages of Circuit Switching:

1. Inefficient for Bursty Traffic: Circuit switching is not efficient for bursty traffic, where data is transmitted in short bursts with idle periods in between. The resources remain reserved even during the idle periods, resulting in underutilization of the network capacity.

2. Inflexible: Circuit switching is inflexible as the resources are dedicated to a specific session. It is not suitable for situations where the communication requirements change dynamically.

In conclusion, circuit switching is a method in which the required resources for communication between end systems are reserved for the duration of the session. It provides guaranteed quality of service and low latency but is not efficient for bursty traffic and lacks flexibility.