Detecting an active network node using a login attempt

Abstract

A method and apparatus for notifying a first network node that a second network node has gone off-line during a communication session is disclosed. The first network node may be a client and the second network node may be a server. The client and the server communicate using an embedded protocol, such as telnet. The protocol defines a login process that must be used by the client to establish a logical connection to the server. The protocol also specifies that the server must immediately issue a response to a login attempt, by either establishing a connection or issuing an error message. The first network node determines that no communications have been received from the second server in a pre-determined period of time. The first network node generates invalid login information, such as a randomly generated invalid user id and an invalid password. A login command is sent from the first network node to the second network node. The login command includes the previously generated invalid login information. The second network node responds, indicating that the login information is invalid or that login is refused. The response provides a positive indication to the first network node that the second network node is on-line. The process can be repeated frequently without requiring any significant system resources. If the second network node does not immediately respond, the communication session can be recovered or terminated, thereby maximizing system resources.