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host A host B | seq=92 , 8 bytes data | |______________________| | | | ×los_____

ID: 3691457 • Letter: H

Question

              host A                       host B
             | seq=92 , 8 bytes data     |
             |______________________|
             |                                             |
             | ×los___________ACK_ |
             | seq=92 , 8 bytes              |
             |______________________|
             |                                             |
             |            ACK =?                    |
sendBase____________________|
    =?     |                                             |
             |                                             |
         time
                                     (a)


              host A                           host B
                        |                                           |
                        | seq=92 , 8 bytes data   |
                        |_____________________|
                        |                      ACK=100    |
                        |    los ×______________ |
                        |                                            |
                        | seq=100 , 20 bytes data|
                        | _____________________ |
                        |                                             |
                        |                          ACK =?      |
                        |______________________|
sendBase      |                                          |
=?                    |                                          |
                   time
                                         ( b )


the figure above two scenarios in which host A send some packets to host B. Both users use TCP.
a ) In the first case, what will be the acknowledgment number of the last ACK sent by host B? What will be the new sendBase when host A receives the acknowledgement?
b ) In the second case, what will be the acknowledgment number of the last ACK sent by host B? What will be the new sendBase when host A receives the acknowledgement?












Explanation / Answer

a) ACK = 100
      sendBase= 100

b) ACK = 120
    sendBase= 120