Discussion Assignment Unit 6 CS 2204-01 Communications and Networking - AY2023-T5 University of the People Majd Alhaddad Consider a simple application-level protocol built on top of UDP that allows a client to retrieve a file from a remote server residing at a well-known address. The client first sends a request with a file name, and the server responds with a sequence of data packets containing different parts of the requested file. To ensure reliability and sequenced delivery, client and server use a stop-and-wait protocol. Ignoring the obvious performance issue, do you see a problem with this protocol? Think carefully about the possibility of processes crashing. The characteristics of using such a protocol are concentrated in the following points: · In this flow control method, the sender sends one frame to the receiver and waits for an acknowledgment of receipt. · The next frame is sent by the sender only when an acknowledgment of the previous frame is received. · The process of sending a frame and waiting for an acknowledgment continues as long as the sender has data to send. · To terminate the sender's transmission at the end of the EOT frame. · The next frame is only sent when the first frame is recognized, so there is no chance of a frame being lost. · The main drawback of this method is that it is inefficient and makes the transfer process slow. In this method, the single frame is transmitted from the source to the destination and the single acknowledgement is transmitted from the destination to the source. . As a result each frame sent and received uses the full time needed to traverse the link, furthermore if two devices are far apart, a lot of time is wasted waiting for ACK messages which increases the total transmission time. · The sender places the data packet on the transmission link. · The data packet propagates towards the receiving end.
· The data packet reaches the receiver and waits in its own buffer. · The receiver handles the data packet. · The recipient places an acknowledgment on the sending link. · The acknowledgment is posted at the sender's end. · The acknowledgment reaches the sender and waits in its buffer. · The sender handles the acknowledgment. However, the use of such a protocol creates many problems, including: · Only one packet can be sent at a time. · If the distance between the transmitter and the receiver is large, the propagation delay will be greater than the transmission delay, and then the efficiency will be very low. . After each transmission, the sender has to wait for the acknowledgment, and this time will increase the total transmission time, which makes the transmission process slow. . References : Kurose, J., & Ross, K. W. (2007). Study companion, Computer networking, a top- down approach featuring the Internet, third edition, James F. Kurose, Keith W. Ross. https://lib.ugent.be/en/catalog/rug01:001649489 Dordal, P. L. (2014). An Introduction to Computer Networks.