PP Presentation
- With networks you must have distributed algorithms. The problem with simplex stop and wait, the return channel may have an error. Let s=sender, r=receiver
- s, sends a frame to r.
- r sends an ack to s but it is not recieved by s.
- s times out and retransmits
- r obtains 2nd copy of the frame
- This is known as a duplication error!
- To stop duplication errors we add sequence number, e.g. 0,1,2,3...