title: How can I turn on IPCOMP for a socket?
body: <p>For reasons I can't go into, our system uses a very small MTU (128 bytes).  These embedded devices are on a completely separate network so no internet access or interaction with other devices.</p>
  
  <p>Obviously, TCP takes up 66 bytes per packet leaving not very much for payload.  </p>
  
  <p>After some googling, I came across IPCOMP which looks like it may help in reducing the amount of traffic on the network.</p>
  
  <p>My question is how can I enable this?  Is there a setsockopt, or do I need a special driver? </p>
  
  <p>The only example I've seen is:</p>
  
  <pre><code>socket(PF_INET, SOCK_RAW, IPPROTO_COMP)
  </code></pre>
  
  <p>but this means I need to create the IP/TCP/payload manually.</p>
  
  <p>Anyone have experience with this.</p>
  
  <p>EDIT: Perhaps a better method would be to enable cslip or ppp on this connection.  I can find tutorials on enabling PPP on a serial port (for dial-up modem), but nothing on enabling PPP on ethernet.<br>
  I've seen articles on PPPoE, but this seems to add MORE to the payload rather than reducing it.<br>
  Can anyone help with this?</p>