Consider a simple UDP-based protocol for requesting files (based somewhat loosely on the Trivial File Transport Protocol, TFTP). The client sends an initial file request, and the server answers (if the file can be sent) with the first data packet. Client and server then continue with a stop-and-wait transmission mechanism.
(a) Describe a scenario by which a client might request one file but get another; you may allow the client application to exit abruptly and be restarted with the same port.
(b) Propose a change in the protocol that will make this situation much less likely.