|Authors:||James F. Kurose, Keith W. Ross|
Consider the rdt 3.0 protocol. Draw a diagram showing that if the net-work connection between the sender and receiver can reorder messages (that is, that two messages propagating in the medium between the sender and receiver can be reordered), then the alternating-bit protocol will not work correctly (make sure you clearly identify the sense in which it will not work correctly). Your diagram should have the sender on the left and the receiver on the right, with the time axis running down the page, showing data (D) and acknowledgment (A) message exchange. Make sure you indicate the sequence number associated with any data or acknowledgment segment.
rdt 3.0 protocol’s message exchange procedure:
rdt 3.0 stands for reliable data transfer protocol. The following are the steps involved in message exchange.
The following diagram represents the sender and receiver connected through a network. The messages reordering is illustrated:
In the above diagram D0, D1 indicate data with sequence number 0 and 1 respectively. A0, A1, indicates acknowledgements with sequence number 0 and 1 respectively.
Step by step process of message exchange:
The new version of the data D0 received by the receiver is replaced by the old version of the data D0 due to the reordering.
Therefore, the protocol is not working well and message exchange is improper. Data is not transmitted as intended.