Design and describe an utility-degree protocol to be used among an computerized teller system and a bank's centralized laptop. Your protocol should allow a person's card and password to be tested, the account balance (that's maintained at the centralized pc) to be queried, and an account withdrawal to be made (this is, money disbursed to the user). Your protocol entities ought to be able to cope with the all-too-commonplace case wherein there isn't always enough cash within the account to cowl the withdrawal. Specify your protocol by means of list the messages exchanged and the movement taken by the computerized teller machine or the bank's centralized computer on transmission and receipt of messages. Sketch the operation of your protocol for the case of a easy withdrawal without a errors, the usage of a diagram just like that in Figure 1.2. Explicitly kingdom the assumptions made by your protocol about the underlying give up-to-give up delivery provider. P2. Equation 1.1 offers a method for the cease-to-end put off of sending one packet of period L over N links of transmission fee R. Generalize this formulation for sending P such packets again-to-lower back over the N links. P3. Consider an software that transmits information at a consistent rate (for example, the sender generates an N-bit unit of information every ok time devices, where k is small and fixed). Also, while such an utility begins, it'll retain strolling for a fantastically long period of time. Answer the following questions, in brief justi- fying your answer: a. Would a packet-switched network or a circuit-switched network be extra suitable for this software? Why? B. Suppose that a packet-switched network is used and the simplest site visitors in this community comes from such programs as defined above. Further- extra, expect that the sum of the utility facts costs is much less than the capacities of every and every hyperlink. Is some form of congestion control wanted? Why? P4. Consider the circuit-switched community in Figure 1.Thirteen. Recall that there are four circuits on every link. Label the 4 switches A, B, C and D, going within the clockwise route. A. What is the maximum variety of simultaneous connections that may be in development at any individual time in this community? B. Suppose that every one connections are between switches A and C. What is the most wide variety of simultaneous connections that can be in progress? C. Suppose we want to make four connections between switches A and C, and any other 4 connections among switches B and D. Can we course these calls via the 4 links to house all 8 connections? P5. Review the auto-caravan analogy in Section 1.Four. Assume a propagation velocity of 100 km/hour. A. Suppose the caravan travels one hundred fifty km, starting in front of 1 tollbooth, passing via a second tollbooth, and completing just after a third toll- sales space. What is the give up-to-give up postpone?

question 1

Suppose that A and B are decision problems and it is known that both A Sp B and B