Method and apparatus for re-securing resources after a detected bus reset

Abstract

A communication path control system is provided for use in a data network configured by a number of buses each of which installs at least one node as an isochronous resource manager (IRM) based on the IEEE 1394 standard. Adjacent buses are interconnected together by means of a bridge consisting of at least two portals, each of which has a connection counter for counting a number of receiving nodes for receiving stream packets being transmitted thereto from a transmitting node by itself. For establishment of a communication path, a device controller specifies all portals that lie in the communication path to request each of them to increment a value of the connection counter by '1'. For disconnection of the communication path, the device controller requests each of the specified portals to decrement a value of the connection counter by '1'. More specifically, each portal stores a communication path management table containing the connection counter, while the device controller stores a communication path management table that describes resources (e.g., bandwidths, channels) in connection with a connection counter with respect to each of buses corresponding to the communication path. At occurrence of bus reset on a specific bus, its corresponding portal proceeds to initialization of the specific bus, then, the device controller proceeds to re-securement or release of the resources.