[Boost-users] Why cannot asio tcp socket server detect TCP disconnection when the client device lost power?

Hi, The asio tcp server can detect the disconnection when the client program stop. But I have small device when it lost power, the server won't be able to detect the TCP disconnection. Does the boost socket has TCP timeout? What is an effective way to handle this situation other than running heartbeat in user level? Thank you. Kind regards, - j