Every user want,s to Deliver his message or Data Successfully to the destination Host but it,s not easy for the network so let,s start the title of our Topic is “Stop-and-wait-ARQ” Before going to start our topic let,s discuss some Basics first.
what is Frame ?
Frame just Define packet or data boundary that from where it,s starting and where it will be end.
What is packet ?
To Divide a Large message in to segments (Pieces ) so these number of pieces is called packet
What is Acknowledgement ?
when a sender send packet so how will sender knows that his packet,s is arrived to the destination host or not so when ever the sender send a packet and the receiver received the packet correctly with out error free so he send back ” Acknowledgement single one bit frame ” to Sender that yes i received your packet now you are able to send the next packet .
what is stop-and- wait ?
when sender send a packet so for sender he needs to wait for the acknowledgement if sender receive acknowledgement back from receiver side so it,s means that packet is received successfully so stop and wait means sender will first send packet and wait for a moment which called Time out if sender does not receive acknowledgement at the given time out so sender send the same packet again because he thinks that i did not receive the Ack so that,s mean that packet is not reached correctly to the Reviver side may be packet is lost or drop on the way so he retransmit the same packet
what is ARQ ?
Arq stand,s for Automatic Repeat reQuest stop and wait use ARQ terminology First send packet wait for Ack if not recived Ack retransmit the same packet automatic and wait for the Ack.
what is time out ?
Time out is the specific time if sender not received the Ack at the given timeout so sender will automatically Retransmit the same packet again with out waiting or taking permission from someone.
Still some Problems May Occur
some Time receiver receive The packet successfully But the Ack Drops on the way
some time receiver did not receive the packet successfully
some time receiver receive the Ack too late mean out of the given time-out.