Method for identifying devices in a communication network and device for implementing said method

Abstract

In a 1394 bus, during the bus reset procedure, nodes exchange some Self-id packets. The invention presents a method for a node to build the topology of the bus from the information contained in the Self-id packets. Once the node has collected all the Self-id packets, the node goes over nodes to separate parent nodes (with at least one child) and children nodes (with no child). Then by going over nodes from the smallest Phy-id to the root, one can attribute which node is connected to every port of a given node.

1 - 7 . (canceled).  
   
   
       8 . Method for a node in a network of interconnected nodes to build the network topology, the network being organized in a tree, where each node has at least one communication port, each port being connected to a parent node, a child node or being unconnected, each node possessing a physical identifier from zero to the number of nodes in the network minus one, the root of the tree having the highest physical identifier, the node possessing for each node of the network its physical identifier, and its connection ports with the information whether each port is connected to a parent node, a child node or is unconnected, comprising at least the following steps: 
 separating the parent nodes consisting in nodes with at least one port connected to a child, from the child nodes consisting in nodes with no port connected to a child;    processing each parent node from the node having the smallest physical identifier to the root and attributing the child nodes with the smallest physical identifier to ports of the considered node connected to a child;    suppressing the attributed child nodes from the child nodes set; and    adding a processed parent node to the child nodes set if it has a parent port.    
   
   
       9 . Method according to  claim 8  wherein the network is an IEEE 1394 bus.  
   
   
       10 . Apparatus to be connected to a network of interconnected apparatus wherein each apparatus comprises at least one connection port, the network being organized in a tree, each port being connected to a parent apparatus, a child apparatus or being unconnected, each apparatus in the network having a physical identifier from zero to the number of apparatus in the network minus one, the root of the tree having the highest physical identifier, the apparatus possessing for each node of the network its physical identifier, and its connection ports with the information whether each port is connected to a parent node, a childe node or is unconnected, the apparatus comprising: 
 means for separating the parent nodes consisting in nodes with at least one port connected to a child, from the child nodes consisting in nodes with no port connected to a child; and    means for processing parent nodes from node having the smallest physical identifier to the root and for each parent node, attributing the child nodes with the smallest physical identifier to ports of the considered node connected to a child and adding the processed parent node to the child nodes set if it has a parent port while suppressing the attributed child nodes from the child nodes set.    
   
   
       11 . Apparatus according to  claim 10 , wherein the network is an IEEE 1394 bus.