Apparatus for and method of releasing stuck virtual circuits in an asynchronous transfer mode network

A method of releasing a stuck virtual circuit, wherein the last cell of a frame transmitted on said virtual circuit is not received, said method comprising the steps of:

• setting a first_cell bit upon reception of the first cell of a frame on said virtual circuit;
• setting a last_cell bit upon reception of a cell on said virtual circuit having an end of frame indication;
• clearing said last_cell bit upon reception of a cell on said virtual circuit not having an end of frame indication;
• examining on a periodic basis said first_cell bit and said last_cell bit;
• and if said first_cell bit is set,
• clearing said first_cell bit;
• identifying said virtual circuit as a stuck virtual circuit when a first cell has not been received since said first_cell bit was cleared and said last_cell bit is cleared;
• and
• releasing memory resources currently consumed by said stuck virtual circuit.

An apparatus for releasing a stuck virtual circuit, wherein the last cell of a frame transmitted on said virtual circuit is not received, comprising:

• a control memory adapted to store, for each virtual circuit, a first_cell bit and a last_cell bit;
• a cell processor operative to:
• set a first_cell bit upon reception of the first cell of a frame on said virtual circuit;
• set a last_cell bit upon reception of a cell on said virtual circuit having an end of frame indication;
• clear said last_cell bit upon reception of a cell on said virtual circuit not having an end of frame indication;
• software means operative on said cell processor to:
• examining said first_cell bit and said last_cell bit periodically;
• and if said first_cell bit is set,
• clearing said first_cell bit;
• and if, after a predetermined period of time, said first_cell bit is cleared and said last_cell bit is cleared then
• identifying said virtual circuit as a stuck virtual circuit;
• and
• means for releasing memory resources currently consumed by said stuck virtual circuit.