0 votes 0 votes A channel has propagation delay of 10 ms .For 320 bits frame what will be channel bit rate if stop -n-wait give efficiency of 50%? I have solved this using 2 approaches but getting different answers(as in the picture). Can anyone plz explain where i am wrong? komal07 asked Dec 30, 2015 komal07 1.2k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Your first approach is not understandable. Why are you multiplying propagation delay with the Bandwidth? I think it will not give total amount of data that could be sent. Method 2 is correct. monanshi answered Dec 30, 2015 monanshi comment Share Follow See all 4 Comments See all 4 4 Comments reply komal07 commented Dec 30, 2015 reply Follow Share In below link to calculate utilization size of frame/bandwidth delay product is done..thats why i multiplied RTT with B/w .. https://books.google.co.in/books?id=bwUNZvJbEeQC&pg=PA322&lpg=PA322&dq=in+stop+and+wait+ARQ+bandwidth+1Mbps+and+1+bit+take+20+ms+to+make+a+round+trip+if+system+data+frame+are+1000&source=bl&ots=qsr_E9SupI&sig=xQkLId_-8ZCZ8qAFWoG9D3aebSQ&hl=en&sa=X&ved=0ahUKEwj9u4qo3YPKAhVRTo4KHWQ2Bd4Q6AEILTAD#v=onepage&q=in%20stop%20and%20wait%20ARQ%20bandwidth%201Mbps%20and%201%20bit%20take%2020%20ms%20to%20make%20a%20round%20trip%20if%20system%20data%20frame%20are%201000&f=false 0 votes 0 votes komal07 commented Dec 30, 2015 reply Follow Share actually bandwidth delay product should be 2*B*10^-2..but then also answers not same 0 votes 0 votes Anoop Sonkar commented Dec 30, 2015 reply Follow Share how second method is correct? formula used here for link utilization not for efficiency(in efficiency we consider only RTT and do not consider other overhead). first method is almost correct only mistake is instead of pt*B, it should be RTT*B and answer will be 32 0 votes 0 votes komal07 commented Jan 2, 2016 reply Follow Share isn't utilization and efficiency same? 0 votes 0 votes Please log in or register to add a comment.