[b] [/b]Hi , i would like to get a c program for selective repeat protocol ..and i also wpould like to have a detail description on its working.....hope you will help me....
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Selective repetition is a connection-oriented protocol in which both the transmitter and the receiver have a sequence number window. The protocol simulation shows a time sequence diagram with users A and B, the protocol entities A and B that support them, and a communication medium that carries messages. Users request data transmissions with DatReq (DATAn) and receive data transmissions such as DatInd (DATAn). The data messages are simply numbered DATA0, DATA1, etc. without explicit content. The transmission protocol sends the DT (n) protocol message which provides only the sequence number, not the data. Once the sequence numbers reach a maximum number (such as 7), they are wrapped back to 0. An acknowledgment AK (n) means that the DT message numbered n is the next expected message (ie all messages up to but not include this number have been received). Since the sequence numbers are wrapped, an acknowledgment with the sequence number 1 refers to messages 0, 1, 7, 6, and so on. Note that if a DT message is received again due to retransmission, it is acknowledged but discarded.The protocol has a maximum number of messages that can be sent without confirmation. If this window is full, the protocol is blocked until an acknowledgment is received for the first pending message. At this point, the transmitter is free to send more messages.