title: How does MPLS header give information about the next protocol?
body: <p>How does MPLS header give information about the next protocol ?  </p>
  
  <p>I did some research on internet , and found that the router holds that information, since router is the one assigning the labels.</p>
  
  <p>But there must be some information about next protocol passed on at every label switching which can be extracted when packet goes out of mpls domain.</p>