@Override
  public boolean process(SmppSimulatorSessionHandler session, Channel channel, Pdu pdu)
      throws Exception {
    // anything other than a bind is super bad!
    if (!(pdu instanceof BaseBind)) {
      if (pdu instanceof PduRequest) {
        session.addPduToWriteOnNextPduReceived(
            ((PduRequest) pdu).createGenericNack(SmppConstants.STATUS_INVBNDSTS));
        return true;
      } else {
        // logger.error("PDU response received, but not bound");
        channel.close();
        return true;
      }
    }

    BaseBind bind = (BaseBind) pdu;
    BaseBindResp bindResp = (BaseBindResp) bind.createResponse();

    if (!bind.getSystemId().equals(systemId)) {
      bindResp.setCommandStatus(SmppConstants.STATUS_INVSYSID);
    } else if (!bind.getPassword().equals(password)) {
      bindResp.setCommandStatus(SmppConstants.STATUS_INVPASWD);
    }

    session.addPduToWriteOnNextPduReceived(bindResp);
    return true;
  }
  protected BaseBindResp createBindResponse(BaseBind bindRequest, int statusCode) {
    BaseBindResp bindResponse = (BaseBindResp) bindRequest.createResponse();
    bindResponse.setCommandStatus(statusCode);
    bindResponse.setSystemId(configuration.getSystemId());

    // if the server supports an SMPP server version >= 3.4 AND the bind request
    // included an interface version >= 3.4, include an optional parameter with configured
    // sc_interface_version TLV
    if (configuration.getInterfaceVersion() >= SmppConstants.VERSION_3_4
        && bindRequest.getInterfaceVersion() >= SmppConstants.VERSION_3_4) {
      Tlv scInterfaceVersion =
          new Tlv(
              SmppConstants.TAG_SC_INTERFACE_VERSION,
              new byte[] {configuration.getInterfaceVersion()});
      bindResponse.addOptionalParameter(scInterfaceVersion);
    }

    return bindResponse;
  }