GATE IT 2007 | Question: 74

Question

Consider a token ring topology with N stations (numbered 1 to N) running token ring protocol where the stations are equally spaced. When a station gets the token it is allowed to send one frame of fixed size. Ring latency is t_p, while the transmission time of a frame is t_t. All other latencies can be neglected.

The maximum utilization of the token ring when t_t =3 ms, t_p = 5 ms, N = 10 is

• A. 0.545
• B. 0.6
• C. 0.857
• D. 0.961

Comments

Not in the current syllabus of Gate CS

Answer 1

Answer is C

Maximum efficiency of token ring, early token release when every one wants to transmit

=(t_x)/(t_x +( t_p/n))

t_x=here given as t_t= 3 ms

t_p =5 ms and N=10,

so efficiency = 3/(3+.5)= .857

Answer 2

Answer is (C)