What are two reasons for using layered protocols? what is one possible disadvantage of using layered protocols?

Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below. internet speed levels of "fast comma " "medium comma " and "slow" choose the correct answer below. a. the ordinal level of measurement is most appropriate because the data can be ordered comma but differences left parenthesis obtained by subtraction right parenthesis cannot be found or are meaningless. nothing nothing nothing nothing nothing b. the interval level of measurement is most appropriate because the data can be ordered comma differences left parenthesis obtained by subtraction right parenthesis can be found and are meaningful comma and there is no natural starting point. c. the nominal level of measurement is most appropriate because the data cannot be ordered. nothing d. the ratio level of measurement is most appropriate because the data can be ordered comma differences left parenthesis obtained by subtraction right parenthesis can be found and are meaningful comma and there is a natural starting point.

Consider a slotted aloha system, where the time slot equals the fixed duration of each packet. assume that there are 4 stations a,b,c,d sharing the medium. (a) stations a,b,c,d receive one packet each from higher layers at times 1.3, 1.5, 2.6,5.7 respectively. show which transmissions take place when, according to the slottedaloha protocol; describe all transmissions until all four packets have been successful.when needed, each station has access to the following sequence of random number, provided by a random number generator and drawn uniformly between 0 and 1: (1) station a draws numbers: 0.31, 0.27, 0.78, 0.9, 0.9, 0.11, 0. (2) station b draws numbers: 0.45, 0.28, 0.11, 0.83, 0.37, 0.22, 0. (3)station c draws numbers: 0.1, 0.2, 0.3, 0.4, 0. (4) station d draws numbers: 0.36, 0.77, 0.9, 0.1, 0.1, 0.1, 0.1, 0. (b) in slotted aloha, a station transmits in each time slot with a given probability. what probabilities would you assign to each of the four stations so as to: (i) maximize the efficiency of the protocol? (ii) maximize fairness among the four stations? (c) will the efficiency increase or decrease if we modify slotted aloha as follows: (i) get rid of slots and allow stations to transmit immediately? (ii) implement carrier sensing? (iii) implement collision detection? (iv) implement collision avoidance?

What is the primary difference between the header section of a document and the body? a. the body is displayed on the webpage and the header is not. b. the header is displayed on the webpage and the body is not. c. the tag for the body is self-closing, but the tags for the headers must be closed. d. the tag for the header is self closing, but the tag for the body must be closed.