Circuit switching

Circuit switching
•a path is set up in the network between the sender and the receiver (by making the appropriate connections in the switches)
•the necessary network resources are reserved for the connection prior to any data transfer; if this is not possible, the connection request is blocked
•these reserved resources are then held for the duration of the connection, regardless of actual usage
 network links are not shared at the same time
•the links in a path are mono polised for the duration of the connection, then released so that they are available for other connections
•the connection set-up delay can be significant (>1 second)
•circuit switching is ideal for “smooth” network traffic
•e.g. telephone network
•what if the traffic from sender to receiver is “bursty” (which means it varies widely around its average value) ?
•computer-to-computer traffic can be very bursty
*could set up a new circuit for each burst
*could hold original circuit for duration of data transfer
•both of these solutions are wasteful of network resources