title: What are the retransmission rules for TCP?
body: <p>The <a href="http://en.wikipedia.org/wiki/Transmission_Control_Protocol" rel="noreferrer">Wikipedia article on TCP</a> indicates that the IP packets transporting TCP segments can sometimes go lost, and that TCP "requests retransmission of lost data".</p>
  
  <p>What exactly are the rules for requesting retransmission of lost data? At what time frequency are the retransmission requests performed? Is there an upper bound on the number? Is there functionality for the client to indicate to the server to forget about the whole TCP segment for which part went missing when the IP packet went missing?</p>