A factor in the delay of a store$-$and$-$forward packet$-$switching system is how long it takes to store and forward a packet through a switch. If switching time is $20$ usec, is this likely to be a major factor in the response of a client$-$server system where the client is in New York and the server is in California? Assume the propagation speed in copper and fiber to be $2/3$ the speed of light in vacuum.