Answer - The primary advantage of using circuit switching is that it ensures the availability of resources. That is it reserves the network resources required for a specific transfer prior to the transmission taking place. By doing so it ensures that no packet would be dropped and the required quality of service is met. The disadvantage of using circuit switching is that it requires a round trip message to setup a reservation. By doing so as it provisions the resources ahead of the transmission it might lead to the suboptimal use of resources. Circuit switching can be implemented for applications that have constant demand for network resources for long periods of time.