code: public String getSystemNetworkId()
  	{
  		String ipAddress = getConfig().getSystemIpAddress();
  		if (!EventUtils.isEmptyOrNull(ipAddress)) {
  			return ipAddress;
  		}
  		if (EventUtils.isEmptyOrNull(systemNetworkAccessPointId)) {
  			// No set System Address, will attempt to look it up
  			try {
  				InetAddress localAddress = InetAddress.getLocalHost();
  				systemNetworkAccessPointId = localAddress.getHostAddress();
  			} catch (Exception e) {
  				LOGGER.error("Unable to get system IP address, defaulting to localhost");
  				systemNetworkAccessPointId = "localhost";
  			}
  		}
  		return systemNetworkAccessPointId;
  	}
docs: Get the system's ActiveParticipant Network ID  for use
  in audit messages.  Configuration is the default value
  used.  If no value is set in configuration, then Java
  will attempt to determine your system's IP address.  If
  Java cannot determine your system's IP address, then localhost
  is used.
  
  @see org.openhealthtools.ihe.atna.auditor.context.AuditorModuleConfig#setSystemIpAddress(String)
  @return The system's ActiveParticipant NetworkID