private void startSession() {
   SipClientConnection scc = null;
   try {
     // <i><b>start a listener for incoming requests</b></i>
     startListener();
     // <i><b>open SIP connection with remote user</b></i>
     scc = (SipClientConnection) Connector.open(address.getString());
     scc.setListener(this);
     // <i><b>initialize INVITE request</b></i>
     scc.initRequest("INVITE", scn);
     scc.setHeader("Content-Length", "" + sdp.length());
     scc.setHeader("Content-Type", "application/sdp");
     OutputStream os = scc.openContentOutputStream();
     os.write(sdp.getBytes());
     os.close(); // <i><b>close and send</b></i>
     str = new StringItem("Inviting... ", scc.getHeader("To"));
     form.append(str);
   } catch (Exception ex) {
     ex.printStackTrace();
     // <i><b>handle IOException</b></i>
   }
 }