title: How long does it take to send a file of 640,000 bits from host A to host B over a circuit-switched network?
body: <p>Just going over an exam question and can't figure out the correct method to solve it. The question is as follows :</p>
  
  <pre><code>How long does it take to send a file of
  640,000 bits from host A to host B over a
  circuit-switched network?
  
   - All links are 1.536 Mb/s
   - Each link uses TDM with 24 slots/sec (TDM = Time Division Multiplexing)
   - 500 msec to establish end-to-end circuit  
  </code></pre>
  
  <p>To my mind, then, the answer would be</p>
  
  <pre><code> x = (1.536 * 10^6) / 24
   y = 640,000 / x.
   Answer : y + 500 * 10^-3
  </code></pre>
  
  <p>I have a feeling this is catastrophically wrong though. Can anyone help me out please ? :) </p>