Vanko A Vankov

US Patent:

8135990, Mar 13, 2012

Filed:

Aug 6, 2007

Appl. No.:

11/834058

Inventors:

Vanko Vankov - San Francisco CA, US
Vinod Jeyachandran - Rockville MD, US
Pradeep K. Singh - Arlington VA, US
Alain J. Cohen - McLean VA, US
Shobana Narayanaswamy - Kensington MD, US

Assignee:

OPNET Technologies, Inc. - Bethesda MD

International Classification:

G06F 11/00

US Classification:

714 33, 714 41, 714 46, 714 57

Abstract:

Network survivability is quantified in such a way that failure cases can be compared and ranked against each other in terms of the severity of their impact on the various performance measures associated with the network. The degradation in network performance caused by each failure is quantified based on user-defined sets of thresholds of degradation severity for each performance measure. Each failure is simulated using a model of the network, and a degradation vector is determined for each simulated failure. A comparison function is defined to map the degradation vectors into an ordered set, and this ordered set is used to create an ordered list of network failures, in order of the network degradation caused by each failure.

US Patent:

20090052333, Feb 26, 2009

Filed:

Aug 20, 2008

Appl. No.:

12/195393

Inventors:

Vanko Vankov - San Francisco CA, US
Arun Pasupathy - Gaithersburg MD, US
Vinod Jeyachandran - Rockville MD, US
Pradeep K. Singh - McLean VA, US
Alain J. Cohen - McLean VA, US
Yonghuan Cao - Morrisville NC, US

International Classification:

G06F 11/30

US Classification:

370242

Abstract:

First-order effects of hypothesized fault conditions are determined by propagating discrete test packets between select nodes and noting the change of path, if any, taken by the test packet under each condition relative to the fault-free path. Tools are provided to create classes of node pairs of interest, and test packets are created only for select classes. The network is analyzed to identify fault conditions that are likely to impact system performance, and only these fault conditions are simulated. By providing a methodology for selecting classes of node pairs to test, and prioritizing the faults to simulate, a first-order survivability analysis of large networks can be performed efficiently and effectively. The efficiency of this technique is also enhanced by providing test packets that are representative of a wide range of possible source-destination combinations, and by evaluating only the source-destination combinations that may be directly affected by each fault condition.

US Patent:

20130007524, Jan 3, 2013

Filed:

Mar 6, 2012

Appl. No.:

13/412623

Inventors:

Vanko VANKOV - Portland OR, US
Vinod JEYACHANDRAN - Rockville MD, US
Pradeep K. SINGH - Arlington VA, US
Alain J. COHEN - McLean VA, US
Shobana NARAYANASWAMY - Kensington MD, US

Assignee:

OPNET Technologies, Inc. - Bethesda MD

International Classification:

G06F 11/263

US Classification:

714 32, 714E11177

Abstract:

Network survivability is quantified in such a way that failure cases can be compared and ranked against each other in terms of the severity of their impact on the various performance measures associated with the network. The degradation in network performance caused by each failure is quantified based on user-defined sets of thresholds of degradation severity for each performance measure. Each failure is simulated using a model of the network, and a degradation vector is determined for each simulated failure. A comparison function is defined to map the degradation vectors into an ordered set, and this ordered set is used to create an ordered list of network failures, in order of the network degradation caused by each failure.