Hello,

Please support providing a solution for the below-mentioned question for understanding the concepts.

Q5. (a) Define what is meant by the term "Window Flow Control" in relation to communication networks. Explain the role of the "SEQ" identifier in such a scheme. Define the essential difference between frame and byte -based approaches and give examples of where each are deployed. Window-based schemes often make use of an "ACK" identifier to work alongside the "SEQ" identifier. Explain its role and general operation. (b) Donald is using a personal laptop via his home router to access a server run by VP Enterprises located in Moscow to facilitate a series of file transfers. This access is facilitated via a secure connection using byte-based window flow control mechanism running at 2.048 Mb/s. At the time of setup, Donald's link to the server has around a round-trip latency of 512mS and a BER of 106. i) To confirm operation of the link, Donald intends first to send a series of test messages each 16kBytes long. For such a message size, determine an appropriate window size to minimise delay. ii) The window size field in each message is limited to 2 bytes. Comment upon the implications of such a limit on the result of part i). iii) Donald then sends 6 messages (each 16 kBytes long) to VP Enterprises. Determine the time it takes to successfully transfer all 6 messages. (c) Donald is rather unhappy at what he considers the unresponsive and slow nature of the file transfer service offered by VP Enterprises and he calls the CEO of VP Enterprises (Vladimir) to complain. The CEO suggests two possibilities to improve the situation. The first is to increase the link rate to 8.192 Mbytes while the second is a proposal that rather than send individual 16 kByte messages he consolidates these into maximum size messages of 64 kBytes. Sending fewer messages but faster is the proposal. Comment upon the appropriateness of this proposal in both quantitative and qualitative terms