I found nothing about the default value of heart beat mechanism in official doc

I tried to find a result in source code, nothing found!

here are definition, but no default values

/**
* Heart beat interval. Time unit: millisecond.
*/
	private Integer heartBeatInterval;

	/**
* Heart beat timeout. Time unit: millisecond.
*/
	private Integer heartBeatTimeout;

	/**
* Ip delete timeout. Time unit: millisecond.
*/
	private Integer ipDeleteTimeout;

Do default values same as older version?