Abstract: A first form of an ATM channel testing apparatus tests an ATM channel by having a test cell detector in each switch to detect whether or not the switch appropriately switches a test cell generated by a test cell generating trunk. A second form of an ATM channel testing apparatus easily tests an ATM channel by having test cell generators provided for the respective input highways sequentially generating test cells including test cell identifying information and input highway identifying information, and having test cell checkers provided respectively for the output highways simply tally the test cells by the respective input highways. A third form of an ATM channel testing apparatus tests an ATM channel with less pieces of hardware by having turnaround parts in respective ordinary trunks sequentially turn around a test cell generated by a test cell generating trunk to be finally returned to the test cell generating trunk.

Abstract: An in-service activator for a broadband exchanger has a dual system structure, in which a first system and a second system form a dual pair. The first system and the second system in the dual pair each has at least one [1] channel converter and a switcher. A channel converter stores channel setting information for use in routing a cell inputted from a line, and outputs the cell inputted from the line by attaching the channel setting information to the cell. The switcher switches a cell outputted from a channel converter. The interfacer stores, in a channel converter of a to-be-activated standby system in the dual pair, the channel setting information read from the corresponding channel converter of an act system in the duplex pair.

Abstract: A virtual channel converter converts a virtual path identifier and a virtual channel identifier, e.g. in a twenty-eight (28) bit frame, attached to the header part of an incoming ATM cell on an input highway to an ATM switcher to identifiers to be attached to an outgoing ATM cell on an output highway capable of fully supporting all the combinations, two hundred fifty-six (256) for example, of a virtual path identifier and a virtual channel identifier no matter where the virtual path identifier and the virtual channel identifier are located in the twenty-eight (28) bit frame. The virtual channel converter comprises a plurality of identifier comparator units and a controller. Each of the identifier comparator units has an input identifier memory for storing an identifier attached to an ATM cell and a comparator for comparing the identifiers of an incoming ATM cell with the identifiers stored in the input identifier memory.

Abstract: The present invention relates to a transmission line test method in the broadband ISDN for assembling an ATM formatted cell into a frame and sending it in the synchronous optical network (SONET) formatted transmission line as a protocol of an optical fiber communication network. First, test data are inserted into an ATM cell according to a command of the central controlling unit in an ATM switching unit. Then, the test cell is sent through an ATM switch in the ATM switching unit after the insertion of the test data; the test data are extracted from the test cell turned around by an ATM layer provided between the ATM switch and the SONET-formatted transmission line or by a subscriber terminal adapter, or from the test frame (including the test cell) turned around by a terminator in the SONET-formatted transmission line or by a network terminator at a subscriber terminal in the transmission line; and finally a transmission test is conducted by checking the data in the line up to each turnaround point.

Abstract: A main processor assigns originated-call processings to each of a plurality of call processors in the sequence of call originations according to the first principle of this invention. A switching state controller collects usage information about a plurality of buffers composing the switching network in the ATM exchanger. The call processors to which call processings are assigned perform the call processings based on the content of switching state controller a main processor assigns a call processing for an originated call to one of a plurality of call processors by referring to the call processing assignment table memory with the virtual channel identifier corresponding to an originated call according to the second principle of this invention thus, call processing loads are distributed among call processors.

Abstract: An index value output circuit outputs an index value in response to a VCI added to the first signaling cell outputted from a terminal unit. A switching data output circuit outputs switching data for determining a path for signaling cells, based on the index value. Hence, by revising the index value according to a congestion state of an ATM switch, the above path is dynamically changed. The same index value is inserted in the second and subsequent signaling cells outputted from the terminal unit. Because switching data are based on the same index value, all signaling cells from the same terminal units are fed to the same signaling terminator.