public void processResponse(ResponseEvent responseReceivedEvent) {

    // Log.info("Registering response...." + sipCallId);

    Response response = (Response) responseReceivedEvent.getResponse();
    int statusCode = response.getStatusCode();
    String method = ((CSeqHeader) response.getHeader(CSeqHeader.NAME)).getMethod();

    Log.debug("Got response " + response);

    if (statusCode == Response.OK) {
      isRegistered = true;

      Log.info(
          "Voice bridge successfully registered with "
              + registrar
              + " for "
              + proxyCredentials.getXmppUserName());
      PluginImpl.sipRegisterStatus = "Registered ok with " + proxyCredentials.getHost();

      sipServerCallback.removeSipListener(sipCallId);

    } else if (statusCode == Response.UNAUTHORIZED
        || statusCode == Response.PROXY_AUTHENTICATION_REQUIRED) {

      if (method.equals(Request.REGISTER)) {
        CSeqHeader cseq = (CSeqHeader) response.getHeader(CSeqHeader.NAME);

        if (cseq.getSequenceNumber() < 2) {

          ClientTransaction regTrans =
              SipService.handleChallenge(
                  response, responseReceivedEvent.getClientTransaction(), proxyCredentials);

          if (regTrans != null) {
            try {
              regTrans.sendRequest();

            } catch (Exception e) {

              Log.info("Registration failed, cannot send transaction " + e);
              PluginImpl.sipRegisterStatus = "Registration error " + e.toString();
            }

          } else {
            Log.info("Registration failed, cannot create transaction");
            PluginImpl.sipRegisterStatus = "Registration cannot create transaction";
          }

        } else {
          Log.info("Registration failed " + responseReceivedEvent);
          PluginImpl.sipRegisterStatus = "Registration failed";
        }
      }

    } else {
      Log.info("Unrecognized response:  " + response);
    }
  }
  public void unregister() throws IOException {
    if (!isRegistered) {
      return;
    }

    cancelPendingRegistrations();
    isRegistered = false;

    if (this.registerRequest == null) {
      Log.info("Couldn't find the initial register request");
      throw new IOException("Couldn't find the initial register request");
    }

    Request unregisterRequest = (Request) registerRequest.clone();

    try {
      unregisterRequest.getExpires().setExpires(0);
      CSeqHeader cSeqHeader = (CSeqHeader) unregisterRequest.getHeader(CSeqHeader.NAME);
      // [issue 1] - increment registration cseq number
      // reported by - Roberto Tealdi <*****@*****.**>
      cSeqHeader.setSequenceNumber(cSeqHeader.getSequenceNumber() + 1);
    } catch (InvalidArgumentException e) {
      Log.info("Unable to set Expires Header " + e.getMessage());
      return;
    }

    ClientTransaction unregisterTransaction = null;

    try {
      unregisterTransaction = sipProvider.getNewClientTransaction(unregisterRequest);
    } catch (TransactionUnavailableException e) {
      throw new IOException("Unable to create a unregister transaction " + e.getMessage());
    }
    try {
      unregisterTransaction.sendRequest();
    } catch (SipException e) {
      Log.info("Faied to send unregister request " + e.getMessage());
      return;
    }
  }