实现心跳机制，用来判断对方（设备，进程或其它网元）是否正常运行，采用定时发送简单的通讯包，如果在指定时间段内未收到对方响应，则判断对方已经离线。用于检测TCP的异常断开。-To achieve the heartbeat mechanism used to determine each other (equipment, process, or other network elements) is functioning, the use of communication time to sen