Connectionless ATM data services

Apparatus for transferring data messages, without establishing a connection between users, in an Asynchronous Transfer Mode system otherwise using established connections for data message transfers through a given network comprising a plurality of switching nodes (11), a plurality of user units (15) each connected to one of the switching nodes, and a network management center (17, 19), the apparatus comprising:

• A) means (43, 47, 53) associated with the switching nodes for allocating a Routing Identifier RI to any user unit being activated at a specific network location for connectionless data transfer services,
• said Routing Identifier RI indicating routing information to a location of the user, not established by a connection set-up procedure which establishes a connection between two users wanting to communicate and remaining the same value throughout the network;
• B) in each switching node of said network, table means (51, 53) including at least a portion of said Routing Identifier RI and respective routing directions for correctly routing a message cell containing the Routing Identifier RI;
• C) in the network management center, means (59, 61) for maintaining a global table including the address of each user unit activated for connectionless service, together with the allocated Routing Identifier RI, and means (55, 59) for updating the global table each time a new Routing Identifier RI is allocated to a user unit;
• and
• D) in each user unit:
• D1) means (27, 31) for transmitting, when the user unit desires to send a data message in connectionless mode to another user, a signalling message to said network management center requesting the destination user's Routing Identifier RI,
• D2) means (27, 33) for receiving, from said network management center in a signalling message the respective Routing Identifier RI if existing, and
• D3) means (21, 23, 33) for sending a data message to said another user by including said received Routing Identifier RI in the header of at least one cell of said data message.

An user terminal for connecting to an Asynchronous Transfer Mode Network said user terminal including:

• means located in said user terminal for transmitting, when the user terminal desires to send a data message to another user terminal in the connectionless mode, a signalling message to a network management center requesting a Routing Identifier RI, said Routing Identifier RI indicating routing information to a location of said another user terminal and is not established by a set-up procedure which establishes a connection between the user terminal and remaining the same value throughout the network and the another user terminal;
• means located in said user terminal for receiving from said network management center a signalling message containing the Routing Identifier RI, if existing;
• means located in said user terminal for including in each ATM cell of a data message transmitted to the another user terminal the Routing Identifier RI and an indicator which alerts nodes in the network that said ATM cell is being transmitted in the connectionless mode;
• and
• means for transmitting each ATM cell into the ATM network.

In an Asynchronous Transfer Mode Network using established connections for data message transfers through the network comprising a plurality of switching nodes (11), a plurality of user units (15) connected to each one of the switching nodes, and a network management center (17, 19), apparatus for transferring data messages, without establishing a connection between users, the apparatus comprising:

• A) means (43, 47, 53) associated with each switching node for allocating a Routing Identifier RI, not established through connection set-up procedures which establish a connection between a pair of user units and identifying routing to a location of a user unit using connectionless data transfer services and remaining the same value throughout the network;
• B) in each switching node of said network, table means (51, 53) including at least a portion of each allocated Routing Identifier RI and respective routing directions for correctly routing a message cell containing the Routing Identifier RI;
• C) in the network management center, means (59, 61) for maintaining a global table including the address of each user unit activated for connectionless service together with the allocated Routing Identifier RI;
• and means (55, 59) for updating this table in response to a message received from each switching node each time a new Routing Identifier RI is allocated to an user unit by the switching node.

Apparatus for transferring data messages, without establishing a connection between users, in an Asynchronous Transfer Mode Network otherwise using established connections for data message transfers through the given network comprising a plurality of switching nodes (11), a plurality of user units (15) connected to each one of the switching nodes, and a network management center (17, 19), the apparatus comprising:

• A) means (43, 47, 53) associated with each switching node for allocating a Routing Identifier RI, not established through connection set-up procedures which define a connection between user units and identifying routing information to a location of an user unit activated at a specific network location, to an user unit using connectionless data transfer services and remaining the same value throughout the network
• B) in each switching node of said network, table means including at least a portion of the allocated Routing Identifier RI and respective routing directions for correctly routing an ATM message cell containing the Routing Identifier RI;
• and
• C) means in each switching node for correlating the RI in the ATM cell with a corresponding RI in the table and routing said ATM cell in accordance with the routing directions associated with said RI.

An apparatus for use in transferring data messages, without establishing a connection between users, in an Asynchronous Transfer Mode Network otherwise using established connections for data message transfers through the network comprising a plurality of switching nodes (11), a plurality of user units (15) connected to each one of the switching nodes, the apparatus comprising;

• a cell handling means (55) for receiving and sending signalling message cells;
• a network management center coupled to the cell handling means;
• said network management center including a global table including an address of each user unit activated for connectionless service and Routing Identifiers RIs, each one of the Routing Identifier RI associated with the address of each user unit with said each one of the Routing Identifier RI indicating routing to a location of the user unit in the network, not established by connection set-up procedures which indicate a connection between the user units wanting to communicate and remaining the same value throughout the network;
• and
• means for selectively updating the global table in response to a Routing Identifier RI being allocated to a user unit.

An asynchronous transfer mode network comprising:

• a plurality of switching nodes (11);
• user units (15) connected to the switching nodes;
• a network management center (17, 19) coupled to the plurality of switching nodes and user units;
• A) means (43, 47, 53) associated with the switching nodes for allocating a Routing Identifier RI to any user unit being activated at a specific network location for connectionless data transfer services;
• said Routing Identifier RI indicating a path to a single user unit to which message cells are to be routed, not established by a connection set-up procedure which establishes connection between user units wanting to communicate and remaining the same value throughout the network;
• B) in each switching node of said network, table means (51, 53) including a portion of each allocated Routing Identifier RI and respective routing directions for correctly routing a message cell containing a Routing Identifier RI, to the respective user unit;
• C) in the network management center, means (59, 61) for maintaining a global table including the address of each user unit activated for connectionless service, together with each allocated Routing Identifier RI, and means (55, 59) for updating the global table each time a new Routing Identifier RI is allocated to an user unit;
• and
• D) in each user unit:
• D1) means (27, 31) for transmitting, when the user unit desires to send a data message in connectionless mode to another user unit, a signalling message to said network management center requesting the other user unit Routing Identifier RI,
• D2) means (27, 33) for receiving, from said network management center in a signalling message the respective Routing Identifier RI if existing, and
• D3) means (21, 23, 33) for sending a data message to said another user unit by including said received Routing Identifier RI in the header of at least one cell of said data message.

In an Asynchronous Transfer Mode Network having a plurality of switching nodes, a plurality of user units connected to each one of the switching nodes and a network management center, an apparatus for transferring data messages without establishing a connection between users, said apparatus comprising:

• a first generator for generating an ATM cell including a first field for inserting a Routing Identifier RI, said RI identifying routing to a location of a user unit using connectionless data transfer services, not established through connection set-up procedures which establishes a connection between user units remaining the same value throughout the network;
• a second generator for generating a signalling message requesting the Routing Identifier RI for a named end station;
• means responsive to a response signalling message to extract the Routing Identifier RI and to insert said Routing Identifier RI in the first field of the ATM cell being transferred to the named end station;
• and
• means for transferring/receiving the ATM cell and the signalling message.