# hw2 - (a but assume that the receiver has received packets...

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(1) MTU = 500 Bytes. RTT = 250 ms. Assume the sender will grows its window linearly according to the following formula: W i = W i-1 + 10 and W 0 = 1. When a packet is dropped, the window size will be reduced to W 0 and starts all over again. Assume the network can only sustain 500 Kbps. The TCP channel will perform as shown below. Compute the average capacity that we can transmit through this TCP channel. 2) A data link protocol uses a sliding window for error recovery. Assume the total number of IDs is 8 (i.e. 0, 1, . ., 7). The size of the sending and receiving window is 4. At the beginning, both windows are initialized to 0 1 2 3. (a) Assume a while later, the sender sent out 4 packets 0 1 2 and 3. The receiver has only received 0, 1, 2 but not 3. (a) Suppose all the ACKs sent back by the receiver are lost. What is the sending and receiving window after these events? (b) Repeat part

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Unformatted text preview: (a), but assume that the receiver has received packets 0 1 3 , but not 2. Again all ACKs are lost. 3) Assume RTT of a network = 250 ms. If we like to set up a 200Kbps TCP channel, (a) what is the widow size we need to use? (b) Repeat part (a) for a 2 Mbps. 4) After setting up a TCP channel to a server, a client machine crashes at t0. But it comes back up at t1 and the data rate of the new channel is shown by the red arrows in the figure. Assuming TCP channels always initialize the sequence number to 0. Will we ever have two packets of the same sequence generated by the client machine, before and after the crash, existing in the network? Explain. (Here the client’s port number remains unchanged.) Time Sequence number T T: lifetime of a packet t0: system crashes t1: system resumes t0 t1...
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• Spring '11
• Prof.ShenghuiSong
• Transmission Control Protocol, sliding window, TCP channel, data link protocol, 500 bytes, 200Kbps TCP channel

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