If two host are connected by a link and in middle of the link there is a switch between them, then transmission and propagation time both doubled.
But if for the same link, there is no switch between that two hosts, then propagation time and transmission time will be once
Why that happens? Though both are operating on same link, why only a switch doubles propagation delay and transmission delay time?
In circuit switching resources are allocated (buffer ,bandwidth) early ,before packet is sent .So packet will reach to the destination definately.
As we can see time will be doubled when switch is there due to circuit switching.
Let me know if I m wrong.