title: SPICE protocol extension
body: <p>I am doing a project that extends SPICE. I need to send some custom data between server and client. I beleiev this is done by adding a custom channel to the SPICE protocol</p>
  
  <p>I've got the source code, but it's huge and overwhelming. Can anyone give me a few pointers as to how to start, or direct me to a similar project so I can refer?</p>
  
  <p>Thanks in advance</p>