title: Understanding Bittorrent Tracker Request
body: <p>I'm reading Bittorrent Request parameter that need to be sent to announce URL over <a href="https://wiki.theory.org/index.php/BitTorrentSpecification" rel="nofollow noreferrer">here</a> </p>
  
  <p><strong>Question 1:</strong></p>
  
  <ul>
  <li>left params: </li>
  </ul>
  
  <blockquote>
    <p>left: The number of bytes this client still has to download in base
    ten ASCII. Clarification: The number of bytes needed to download to be
    100% complete and get all the included files in the torrent.</p>
  </blockquote>
  
  <p>also BEEP-3 states </p>
  
  <blockquote>
    <p>The number of bytes this peer still has to download, encoded in base
    ten ascii. Note that this can't be computed from downloaded and the
    file length since it might be a resume, and there's a chance that some
    of the downloaded data failed an integrity check and had to be
    re-downloaded.</p>
  </blockquote>
  
  <p>Now, if I'm starting my torrent download or anytime what possible value should I give to left.</p>
  
  <p><strong>Question 2:</strong></p>
  
  <p><strike>While reading through spec no where I found how often the client should query for announce to get the update lists of peers.</strike></p>
  
  <p><strike>Any word on that </strike></p>
  
  <p>I found this answer to this in term of <code>interval</code> and <code>min interval</code> in the Tracker response.</p>