doubt.

Question

What are the effect of stop & wait protocol on half & full duplex system ?

Answer 1

In stop & wait protocol sender sends the data and waits for the ACK from the receiver during this time sender will not send data, so can both sender and receiver send data together?
It doesn’t matter whether we use half duplex or duplex link because both sender and receiver will not send their packet at the same time.

Comments

Aditya_

but isn’t it like this that both sender and receiver are sending there data after one completed its sending just because the link is half duplex . otherwise both can send at the same time right?

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@Aditya_ for this question if half duplex is mention then what u say ans will be same?

Host A is sending data to host B over a full duplex link. A and B are using the sliding window protocol for flow control. The send and receive window sizes are 5 packets each. Data packets (sent only from A to B) are all 1000 bytes long and the transmission time for such a packet is 50 μs. Acknowledgment packets (sent only from B to A) are very small and require negligible transmission time. The propagation delay over the link is 200 μs. What is the maximum achievable throughput in this communication?

1. 7.69×106 Bps
2. 11.11×106 Bps
3. 12.33×106 Bps
4. 15.00×106 Bps

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@Nisha Bharti No in this case answer will not be same, since sender is sending a window of packets but ACK will be sent be receiver for each packet, so when 1^st packet is received by the receiver then it will send ACK but if the sender is still sending the data then it would not have been possible if half duplex link is there, but here since full duplex link is given sender can continue sending data even when receiver send the ACK for the packet it received. 

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@Pranavpurkar Generally in Stop & wait protocol sender sends a packet and wait for the ACK then sends again so at a time only one station is sending the data so I have written in Stop&wait be it half duplex or full duplex it doesn’t matter but in above question sender is sending the window of data packets so it will send the full window and does not wait for the ACK of the 1^st packet of the window but receiver will send the ACK of the 1^st packet as soon as it receives it, so channel being full duplex or half duplex is important here and changes the answer

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@Aditya_ 

btw i m totaly mad actualy my question is  for SR protocol not STOP & WAIT protocol 

i mistakely written Stop & Wait SORRY.

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@Aditya_

 

Station A needs to send a message consisting of 9 packets to Station B using a sliding window (window size 3) and SR protocol error control strategy. All packets are ready and immediately available for transmission. If every 5th packet that A transmits gets lost (but no acks from B ever get lost), then what is the number of packets that A will transmit for sending the message to B? for full duplex & half duplex, please explain this Aditya*

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@Nisha Bharti number of packets transmitted will be same right be it full duplex or half duplex.

Only difference is in full duplex ACK can be sent at the same time sender is sending the data, in half duplex either ACK will be there or link of data packet. 

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thanku @Aditya_