Method and circuit arrangement for transmitting message cells via redundant, virtual path pairs of an ATM communication network

A method for transmitting message cells for redundant, virtual path pairs formed of an active path and of an alternate path in an ATM communication network operating according to an asynchronous transfer mode, comprising the steps of:

• for each virtual path pair, duplicating message cells to be transmitted via the path pair by a start switching network lying at a start of the respective path pair, the message cells allocated to one another being separately transmitted via the corresponding active path and alternate path;
• providing an end switching network having an output interface at outputs thereof and lying at an end of the respective virtual path pair;
• forwarding message cells transmitted via the active path and the alternate path of the respective path pair to respective outputs of the end switching network, and continuously and separately but simultaneously counting a number of message cells arriving via the active path and via the alternate path;
• and
• if the number of message cells arriving via the alternate path is higher than the number of message cells arriving via the active path by a defined value, the message cells arriving via the alternate path are forwarded by the output interface but the message cells arriving via the active path are discarded.

A method for transmitting message cells for redundant, virtual path pairs respectively formed of an active path and of an alternate path in an ATM communication network operating according to an asynchronous transfer mode, comprising the steps of:

• duplicating message cells to be transmitted via each of the virtual path pairs by providing a start switching network lying at a start of the respective path pair, message cells allocated to one another being separately transmitted via the corresponding active path and alternate path;
• providing an end switching network lying at an end of the respective virtual path pair;
• providing at least one intermediate switching network in each of said active and alternate paths of the respective path pair between the beginning and end switching networks;
• initially discarding message cells transmitted via the alternate path of the respective path pair at an input interface of the end switching network of the respective path pair, but forwarding the message cells transmitted via the active path via an input interface of said end switching network belonging to said active path;
• given an interruption of the active path of the respective path pair occurring prior to said intermediate switching network, transmitting an interrupt signal in a direction toward the end switching network of the respective path pair from said intermediate switching network lying following the interrupt;
• and
• in response to appearance of said interrupt signal at the end switching network of the respective path pair, controlling either the input interface belonging to the alternate path or the input interface belonging to the active path by an internal control signal such that subsequent thereto message cells transmitted via the alternate path are forwarded but message cells transmitted via the active path are discarded.

A method for transmitting message cells for redundant, virtual path pairs respectively formed of an active path and of an alternate path in an ATM communication network operating according to an asynchronous transfer mode, comprising the steps of:

• duplicating message cells to be transmitted via each of the virtual path pairs by providing a start switching network lying at a start of the respective path pair, message cells allocated to one another being separately transmitted via the corresponding active path and alternate path;
• providing an end switching network having an output interface and lying at an end of the paths of the respective path pair between the beginning and end switching networks;
• providing at least one intermediate switching network in each of said active and alternate respective virtual path pair;
• initially discarding message cells transmitted via the alternate path of the respective path pair at an input interface in the end switching network of the respective path pair, but forwarding to said output interface the message cells transmitted via the active path via an input interface of said end switching network belonging to this active path;
• given an interruption of the active path of the respective path pair, transmitting an interrupt signal in a direction toward the end switching network of the respective path pair from said switching intermediate switching network lying following the interrupt;
• and
• in response to appearance of said interrupt signal at the end switching network of the respective path pair, forwarding at the input interface of the alternate path to said output interface message cells which are then transmitted via the alternate path and stopping transmission of message cells via the active path at the input interface thereof.

A circuit arrangement for transmitting message cells in an ATM communication network operating according to an asynchronous transfer mode, comprising:

• redundant, virtual path pairs respectively formed of an active path and of an alternate path for redundantly transmitting message cells;
• a start switching network lying at a start of the respective path pair for duplicating message cells to be transmitted via the respective virtual path pair, message cells allocated to one another being separately transmitted via the corresponding active path or alternate path;
• an end switching network lying at an end of the respective virtual path pair;
• said end switching network of the respective path pair forwarding the message cells transmitted via the active path and via the alternate path to respective outputs thereof;
• a counting unit being provided for each of the corresponding outputs of the respective end switching network for continuously and separately but simultaneously determining a number of message cells arriving via the active path and a number of message cells arriving via the alternate path;
• and
• when the number of message cells arriving via the alternate path that lies above the number of message cells arriving via the active path by a defined value, said counting units controlling the corresponding outputs such that said message cells arriving via the alternate path are forwarded but the message cells arriving via the active path are discarded.

A circuit arrangement for transmitting message cells in an ATM communication network operating according to an asynchronous transfer mode, comprising:

• redundant, virtual path pairs respectively formed of an active path and of an alternate path for redundantly transmitting message cells;
• a start switching network lying at a start of the respective path pair for duplicating message cells to be transmitted via the respective virtual path pair, message cells allocated to one another being separately transmitted via the corresponding active path or alternate path;
• an end switching network lying at an end of the respective virtual path pair having an output interface at outputs thereof;
• said end switching network of the respective path pair forwarding the message cells transmitted via the active path and via the alternate path to respective outputs of said end switching network, an output interface being provided at said respective outputs;
• a counting unit being provided for each of the corresponding outputs of the respective end switching network for continuously and separately but simultaneously determining a number of message cells arriving via the active path and a number of message cells arriving via the alternate path;
• and
• when the number of message cells arriving via the alternate path that lies above the number of message cells arriving via the active path by a defined value, said counting units controlling the corresponding outputs such that said message cells arriving via the alternate path are forwarded by the output interface but the message cells arriving via the active path are discarded.