Long description

Part (a): There is a client at the left in a vertical block with a small block with vertical lines inside it. There is a server on the right a square block with two small blocks with vertical lines inside it. The first block in a server is labeled Old file and the second block in a server is labeled New file. From an old file, a backward arrow labeled 1. The client fetches file points to block labeled 2. Accesses are done on the client on the client-side. From the client's block, the forward arrow is labeled 3. when the client is done, the file is returned to the server. Part (b): There is a vertical block labeled client on the left and the other vertical block labeled server. There is a horizontal block with the vertical lines labeled File stays on the server in the server block. There is a forward arrow labeled Request from client to server and a backward arrow labeled Reply from server to client.