International Business Machines Corporation

Bruno Rousseau

Daniel Orsatti

Ange Aznar

Dominique Rigal

Jean-Claude Zunino

Jose Iruela

Jean Claude Zunino

Jose Iruella

In an ATM cell-relay network usually comprising several switching nodes a method enabling remote surveillance of any entry port to any switching node of the network. The method first assumes that a path is set up from the entry port to a remote observation point. Then, all cells of the incoming traffic, entering entry port to be watched, are duplicated and marked. After which they are transported, unaltered, following the path, up to the observation point. The invention permits that any entry port of an ATM network, that may well span over large geographic areas, be conveniently observable and analyzed transparently i.e., without disturbing users traffic, from a remote location so as network can be maintained and run trouble free.

System and method for enabling remote surveillance of ATM network switching node ports

A method and system for transmitting a loopback cell within an ATM connection. The method comprises the steps of detecting in an input adapter whether or not an incoming ATM cell includes a loopback condition indicator. If so, specific routing labels are appended to the incoming ATM cell indicating that the incoming cell is a loopback cell to be looped back on the connection such that the switch engine of the switching node transfers the loopback cell to the same port of the input adapter utilizing the appended routing labels.

Method for transmitting loopback cells through a switching node of an asynchronous transfer mode (ATM) network

A system and method for merging multiple connections that share a same class of service into a single virtual circuit (VC) in an Asynchronous Transfer Mode (ATM) network. A queuing apparatus includes multiple connection queues for each of the connections, and further includes a scheduled queue corresponding to a particular class of service, wherein contents of the connection queues are transferred into the scheduled queue before being transmitted on the VC. A reassembly queue control block (RQCB) defines a chain of buffer control blocks for the connection queues. Each buffer control block corresponds to a cell belonging to a packet of a particular connection and includes a next buffer address and a lock bit. The chain of buffer control blocks is transferred to a scheduled queue control block (SQCB) in response the lock bit indicating a last packet cell.

Enqueuing apparatus for asynchronous transfer mode (ATM) virtual circuit merging

A system and method for freezing a processing unit to facilitate on-line debugging of a protocol engine within a switching node of a data transmission network. In accordance with the system of the present invention, the protocol engine includes a plurality of processing units such as an identification unit, a lookup unit, a traffic management and congestion unit, an enqueue unit, a dequeue unit, a traffic management scheduling unit, a frame transmission unit, a control unit, and a control block unit. The control block unit includes a freeze register containing multiple freeze bits, wherein each freeze bit is associated with one processing unit. In response to setting a freeze bit, resources and settings of a processing unit associated with the set freeze bit are prevented from being changed by the processing unit.

On-line debugging system in a switching node of a data transmission network

A method and system for enforcing a transmission control parameter for a virtual connection comprising multiple cells within an input port. The virtual connection has a nominal inter-cell arrival rate increment. Each of the cells are associated with a theoretical arrival time and an early arrival limit, wherein a difference of the early arrival limit from said theoretical arrival time delineates a lower boundary of a good zone, while the theoretical arrival time minus the sum of the early arrival limit and the nominal inter-cell arrival rate increment delineates an upper boundary of the good zone. The method includes determining an actual arrival time for an incoming cell from the cells that make up the virtual connection. Next, the actual arrival time is compared to the upper boundary and the lower boundary to determine whether or not the actual arrival time falls within the good zone. In response to determining that the actual arrival time falls within the good zone, the incoming cell is identified as conforming to the transmission control parameter. The method and system of the invention allow to use a finite counter for measuring elapsed time at entry ports of ATM switching nodes, a mandatory feature in order to enforce policing, while avoiding having to manage the overflows of the counter.

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Vence, France

Bruno Rousseau