Gateforum mock 2

Question

 

Comments

Does it mean that the acknowledgements for 0,1 and 3 are also lost bcoz if acknowldegement for 0 is lost then how come we move to 4 ...

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What is RW? Receiver window?

Does content of RW means what Receiver is expecting? Then it should be D.

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given sequence number =3

so window size of sender and receiver  = 4           ...(2^3/2)

sender sends 0 then 1 then 2 then 3

but data packet 2 is lost

so receiver gets packets 0 , 1 and 3 but since 3 is an out of order packet so it sends NACK for packet 2 to the receiver.

hence the next 4 packets that the receiver is expecting is 2 , 4 , 5 ,6.

So D.

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satbir it is asking that what will be content of RW before senders timeout timer expires

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what will be content of RW before senders timeout timer expires

this does not matches any of the options given. and one thing that i am not able to understand is that why senders timeout will expire?

since the receiver is sending ack and Nack both ...sender will know which packet has arrived and which are lost.

sender timer will only expire if sender does not gets any ACK or NACK about a packet till he sends 4 packets to receiver.

packets 0,1,3 should be present in receiving window as packet 2 is lost