Line failure notifying apparatus for terminal apparatus

A network apparatus to which a plurality of terminal apparatuses are connected, comprising:

• a plurality of terminal interfaces for receiving lines connected from the plural terminal apparatuses;
• multiplexing means for bit-multiplexing signals derived from the plural terminal interfaces;
• failure-occurrence-notifying bit producing means for replacing said multiplexed bit stream signal by a failure-occurrence-notifying bit stream which implies an occurrence of a failure when the failure occurred in a line is detected;
• and
• failure-problem processing means for detecting said failure-occurrence-notifying bit stream to thereby process a line failure problem with respect to said terminal apparatus.

A network apparatus to which a plurality of terminal apparatuses are connected, comprising:

• a terminal interface for receiving lines connected from the plural terminal apparatuses, including failure notifying means for notifying an occurrence of a failure to said terminal apparatuses;
• a line interface connected to an external line, including failure detecting means for detecting a failure of said external line;
• an actual data path for transmitting actual data appearing in both said terminal apparatuses and said external line;
• and
• a failure notification path set to said failure detecting means and said failure notifying means.

An ATM switching apparatus interposed between a plurality of own terminal apparatuses and an external line, comprising:

• a terminal interface for receiving lines connected from said plurality of own terminal apparatuses;
• an ATM switch for switching a cell between said plurality of own terminal apparatuses and said external line;
• a line interface for receiving the external line and for including failure detecting means for detecting a failure occurred in the external line;
• path monitoring means for specifying a path of the external line where the failure happens to occur;
• failure-notifying cell producing means for producing and transmitting a failure-notifying cell for notifying an occurrence of a failure to such a terminal apparatus for connecting with the external line where the failure happens to occur in response to information transmitted from said failure detecting means, or said path monitoring means;
• and
• output control means for instructing said ATM switch to be turned OFF.