Question

Token Bucket mechanism is used for congestion control at router. Bucket capacity in 700 Bytes (initially full), token arrival rate is 200 Bytes/sec and maximum output rate is 300 Bytes/sec. The amount of time (in sec) required to transmit 3000 Bytes file is _____.

Comments

19.5?

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https://gateoverflow.in/136469/computer-network

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ohk Sir , Thanks :)

Answer 1

700B Capacity of bucket which is initially filled.
Token Arrival Rate = 200 Bytes/Sec
Max Output Rate= 300 Bytes

Time to transmit 3000 Bytes?

Bursty Traffic Time =
     C + P*S = M*S   (C=Bucket Capacity, P=Token Generating Rate, S= Bursty Time, M=Output Rate)
         700 + 200*S = 300*S
          S = 700/100 = 7 Seconds
For 7 seconds system will generate tokens at full speed of 300 Bytes/Sec, and after that it will switch to 200Bytes/Sec.

In 7 seconds at the speed of 300 Bytes/Sec, 2100 Bytes have been sent and left 900 bytes will be sent at the speed of

200 Bytes/sec which requires further 4.5 seconds.

So, Total time to send 3000 Bytes, it will take 7 + 4.5 = 11.5 Seconds

Comments

After 5 sec it is returning to 200MBPS . Where am I doing wrong??

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what change will ocuur if bucket if empty initially..will it transmitt whole data at token arrival rate

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@Neer01 Yes