Question

An output interface in a switch is designed using the leaky bucket algorithm to send 8000 bytes/s (tick). If the following frames are received in sequence, show the frames that are sent during each second:ch

Answer 1

An output interface in a switch is designed using the leaky bucket algorithm to
send 8000 bytes/s (tick). If the following frames are received in sequence, show the
frames that are sent during each second.
Frames 1, 2, 3, 4: 4000 bytes each
Frames 5, 6, 7: 3200 bytes each
Frames 8, 9: 400 bytes each
Frames 10, 11, 12: 2000 bytes each

Answer 2

Answer:

Second 1: Frames 1,2

Second2: Frames 3,4

Second 3: Frames 5,6

Second 4: Frames 7 to 11

and at second 5: Frame 12

Explanation:

Given Frames with sizes as,

1,2,3,4 each of 4000 Bytes

5,6,7 each of 3200 Bytes

8,9 each of 400 Bytes

10,11,12 each of 2000 Bytes

Second 1: counter set to 8000 Bytes,

Frame 1 is sent and now counter=4000 Bytes

Frame 2 is also sent because counter >= frame 2 size and counter=0 Bytes now.

Frame 3 can't be sent.

Reset the counter.

Second 2:

Frame 3 is sent and now counter=4000 Bytes

Frame 4 is also sent because counter >= frame 2 size and counter=0 Bytes now.

Frame 5 can't be sent.

Reset the counter.

Similarly,

at Second 3:

Frames 5,6 are sent and Frame 7 is rejected because it's size is greater than counter

at Second 4:

Frames 7 to 11 are sent but Frame 12 is rejected for the same reason.

at Second 5:

Frame 12 is sent.