Lab - Reliable Data Transfer

Problem 1.

Visit the Chapter 3 - Go-Back-N Protocol Java applet at the companion Web site. Please read the instructions carefully before proceeding.

1. Experiment with Five Packets:
   • Have the source send five packets.
   • Pause the animation before any of the packets reach the destination.
   • Eliminate the first packet and then resume the animation.
   • Describe what happens. Sender will eventually retransmit all 5 packets
2. Experiment with Acknowledgments:
   • Repeat the experiment, allowing all packets to reach the destination.
   • Kill the first acknowledgment.
   • Describe the outcome. Since Go-Back-N follows cumulative acknowledgement, next acknowledgement will confirm the receipt of the previous packet.
3. Experiment with the Second Packet:
   • Send five packets from the source again.
   • Pause the animation before any packets arrive at the destination.
   • Eliminate the second packet and resume the animation.
   • Describe what happens. Sender will eventually retransmit packets 2, 3, 4 and 5.
4. Experiment with Six Packets:
   • Increase the number of packets sent to six.
   • Describe the outcome.

Cannot send 6 packets. Windows is size 5.

Problem 2.

• Repeat Problem 1 (all questions), but now with Selective Repeat Protocol.

Eventually the first packet gets retransmitted

Eventually the first packet gets retransmitted

Eventually the second packet gets retransmitted

Problem 3.

• List Key Differences Between Selective Repeat and Go-Back-N?

Grading

Post your report including source in Marmoset by the scheduled due date in the syllabus.