Method and system for computer network link with undefined termination condition
View Patent ↗The location of a termination in a properly terminated LAN can be remotely detected. The cable's skin effect produces a detectable signature at the sending-end when a step function, for example, reaches the termination. Accordingly, a network analysis device is connected to the network to inject the step function onto the network cabling. The voltage response of the cabling to this is first digitally sampled and then analyzed in a system controller. The system controller reviews the sampled data for an inflection point and then locates the termination by reference to the delay between when the signal was placed on the cable and the detection of the inflection point.
1. A method for analyzing a network link in a computer network, comprising:
generating a predetermined signal on the network link;
detecting a response of the link to the predetermined signal;
analyzing the response for an influence of a termination of the link, in which the step of analyzing comprises:
applying a short circuit threshold to the response of the link,
applying an open circuit threshold to the response of the link, and
searching the response of the link for a matched terminator;
locating the termination of the link in response to the application of the short circuit threshold, open circuit threshold, and search for the matched terminator; and
determining a time delay between the generation of the predetermined signal and the located termination.
2. The method described in claim 1 , wherein the step of searching for the response of the matched terminator comprises determining a change in the influence of skin effects on the response resulting from the predetermined signal reaching the terminator.
3. The method described in claim 1 , wherein generating the predetermined signal comprises generating a current step function on the network link.
4. The method described in claim 1 , wherein the step of searching for the response of the matched terminator comprises detecting an inflection point in induced voltage on the network link.
5. The method described in claim 1 , further comprising calculating the length of the network link to the terminator in response to the time delay.
6. The method described in claim 1 , wherein the step of analyzing further comprises low pass filtering the response of the link and then detecting an inflection point in filtered response of the network link.
7. The method described in claim 1 , wherein the step of analyzing further comprises low pass filtering the response of the link and then applying the thresholds to the filtered response.
8. The method described in claim 1 , wherein the detection of the response of the link to the predetermined signal occurs at a non-terminator location on the network link.
9. The method described in claim 1 , wherein the generation of the predetermined signal on the network link occurs at a non-terminator location on the network link.
10. The method described in claim 1 , wherein the detection of the response of the link to the predetermined signal occurs on an operational computer network.
11. The method described in claim 1 , wherein the generation of the predetermined signal on the network link occurs on an operational computer network.
12. A network termination analysis device for a digital data network, comprising:
a function generator that injects a predetermined signal onto cabling of the network;
a digitizer that digitally samples the network's response to the predetermined signal; and
a system processor that downloads data from the digitizer to analyze the network's response to the predetermined signal and identify a time between the generation of the predetermined signal and a change in the network's response due to a termination of the network, in which the analysis comprises applying a short circuit threshold to the response, applying an open circuit threshold to the response, and searching the response for a matched terminator.
13. A device as described in claim 12 , wherein the function generator injects a step function.
14. The device described in claim 12 , wherein the system processor calculates at least one length of the cabling based on the time between the generation of the predetermined signal and a change in the network's response exceeding any one of the short or open circuit thresholds or the detection of the matched terminator.
15. The device described in claim 14 , further comprising a monitor for displaying at least one calculated length of the cabling.
16. The device described in claim 15 , wherein the display further indicates a maximum protocol-determined length for the cabling.
17. The device described in claim 12 , wherein the function generator injects the predetermined signal onto cabling of the network at a non-terminator location.
18. The device described in claim 12 , wherein the digitizer samples the network's response to the predetermined signal at a non-terminator location on the cabling.
19. The device described in claim 12 , wherein the function generator injects the predetermined signal onto cabling of an operational network.
20. The device described in claim 12 , wherein the digitizer samples the response to the predetermined signal of an operational network.
21. A method for analyzing a network link in a computer network, comprising:
generating a predetermined signal on the network link;
detecting a response of the link to the predetermined signal, said response including a resistance response;
filtering the response of the link by removing a contribution of a real component of the resistance response of the link; and
displaying the filtered data to assist in the identification of impedance problems on the link.
22. The method described in claim 21 , wherein the detection of the response of the link to the predetermined signal occurs at a non-terminator location on the network link.
23. The method described in claim 21 , wherein the generation of the predetermined signal on the network link occurs at a non-terminator location on the network link.
24. The method described in claim 21 , wherein the detection of the response of the link to the predetermined signal occurs on an operational computer network.
25. The method described in claim 21 , wherein the generation of the predetermined signal on the network link occurs on an operational computer network.