Excavating
Patent
1997-01-21
1999-06-29
Tu, Trinh L.
Excavating
39518307, 39520067, G01R 3128
Patent
active
059178310
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention concerns a procedure for testing an electrical network for data transmission.
In data-transmission and data-communication technology, a number of nodes are linked together through a network. As a node, a computer system as an example or a similar system may be available, and as a network, optical-fiber cables arranged in a star-like configuration may be provided, for example. With the help of existing transmission mechanisms, it is possible that data from one of the nodes can be transmitted through the network to any other arbitrary node.
This kind of transmission mechanism consists in making information available which, proceeding from a first node, indicates the path to a destination node. If data from the first node are to be transmitted to the destination nodes, then, based on this information, the first node can determine which is the next node to which it must send the data on the way to the destination node. This next node, using the information specified above, can determine in the same manner the next node on the path to the destination node and send the data correspondingly. This is repeated until the data reach the destination node and the transmission of the data is completed successfully.
It is possible that one of the nodes of the network has a defect, and that a transmission of information through this node is therefore impossible. This has the result that not only is the node which is impaired by the defect no longer accessible, but any other nodes which are arranged beyond the defective node on the path to an arbitrary destination node, and are hence "in the shadow" of the defective node, are also inaccessible. Typically, all of these nodes are viewed as inaccessible from the first node, therefore there is no differentiation between the nodes located "in the shadow" and which are thus not necessarily defective nodes, and the actual defective node.
It is conceivable that, in a large network, a defect in one single node has as a result that a large number of nodes lie "in the shadow." All of these nodes are regarded, as mentioned above, as inaccessible without differentiation as seen from the first node. Based on the large number of nodes reported alone it is hardly possible for a user to detect the actual defective node and then eliminate the defect.
SUMMARY OF THE INVENTION
It is the object of the invention to create a test system which makes possible the detection of the actual defective node.
This object is achieved in accordance with the invention by the sequential interrogation and testing of nodes along the path to the destination node. The invention makes a test system available by which the actual defective node in the network is automatically detected. In this way it is possible to differentiate between the nodes located "in the shadow" and the actual defective node. A user is hence placed in the position where he can concentrate immediately on the defect of the defective node. The defect can be eliminated quickly without trial and error. No time is lost for testing of the nodes which are "in the shadow." The defect in the network can therefore be eliminated more quickly and the availability of the network is increased. It is clear that this can result in significant cost savings, especially in large networks.
By storing path information at each node along the path to the destination node, the interrogation and testing steps can be consolidated into one step. The test system in accordance with the invention is thus further simplified, and the availability of the network is further increased.
The actual testing of the next node on the path to determine accessibility can be achieved by sending a status query message to that node. Alternatively, the status query can be, in effect, a status message which is automatically generated at periodic time intervals by the node being tested. In both instances, the test system in accordance with the invention receives the information required for the test in accordance with step (b) so that the detec
REFERENCES:
patent: 4745593 (1988-05-01), Stewart
patent: 4977499 (1990-12-01), Banning et al.
patent: 5095444 (1992-03-01), Motles
patent: 5170393 (1992-12-01), Petterson et al.
patent: 5241534 (1993-08-01), Omuro et al.
patent: 5404565 (1995-04-01), Gould et al.
IBM, TDB, vol. 24, No. 10, Mar. 1982, pp. 4974, 4977-4978 "Method for Dynamic Distributed Generation of Explicit Routes".
International Search Report.
Katker Stefan
Paterok Martin
International Business Machines Corporations
Timar John J.
Tu Trinh L.
LandOfFree
System for testing a data-transmission network does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System for testing a data-transmission network, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System for testing a data-transmission network will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1382680