title: mqtt-sn what is the raw data format
body: <p>I am very new to this mqtt-sn stuff. So my question is - how does a mqtt-sn message look like. So I mean the raw data format. I do not clearly understand what octet means. So as I understand an octet is a byte.</p>
  
  <p>So is the data transferred binary?</p>
  
  <p>Or what means octet exact?</p>
  
  <p>Please can someone give me a sample message. It is really bad that there is not example message in the specification.</p>
  
  <p>Thanks,
  Mathias</p>