Patents by Inventor Balachander Krishnamurthy

Balachander Krishnamurthy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6928485
    Abstract: A method for clustering together network clients for guiding of placement of network servers is disclosed. A number of routing table prefix/netmask entries are aggregated and unified into a tubular format. The routing table entries may be converted into a singular format. A network server log is used to extract a number of client IP addresses which are compared to the entries within the unified routing table. A common prefix shared by a number of the client IP addresses and an entry in the unified routing table is determined and used to cluster the clients together in a client cluster. Network servers, such as proxy server, cache servers, content distribution servers and mirror server may be placed in the network according to the client clusters.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: August 9, 2005
    Assignee: AT&T Corp.
    Inventors: Balachander Krishnamurthy, Jia Wang
  • Patent number: 6912562
    Abstract: A Web server maintains, for one or more resources, a respective list of clients who requested that resource. The server takes on the responsibility of notifying all of those clients on when the resource in question changes, thereby letting them know that if the resource is again asked for by a user, an updated copy will have to be requested from the origin server. The server thereupon purges the client list, and then begins rebuilding it as subsequent requests come in for the resource in question. Invalidation messages are sent to selected “victim” clients on the client list, independent of whether the resource in question has changed, when the list meets a predetermined criterion, such as becoming too large. The victim clients may include clients who access the server less frequently than others, clients who have accessed the server in the more distant past than other clients, i.e., using a first-in-first methodology, or clients who have not subscribed to a service that keeps them from being victim clients.
    Type: Grant
    Filed: January 13, 2003
    Date of Patent: June 28, 2005
    Assignee: AT&T Corp.
    Inventors: Balachander Krishnamurthy, Michael Rabinovich
  • Publication number: 20050039086
    Abstract: A sketch-based change detection technique is introduced for anomaly detection and other applications that can benefit from having a quick and efficient change detection mechanism. The technique is capable of detecting significant changes in massive data streams with a large number of network time series. As part of the technique, we designed a variant of the sketch data structure, called k-ary sketch, uses a constant, small amount of memory, and has constant per-record update and reconstruction cost. A variety of time series forecast models are implemented on top of such summaries and detect significant changes by looking for flows with large forecast errors. Heuristics for automatically configuring the forecast model parameters are presented. Real Internet traffic data is used to demonstrate that the sketch-based change detection method is highly accurate when compared with per-flow analysis, and can be implemented at low computation and memory costs.
    Type: Application
    Filed: June 14, 2004
    Publication date: February 17, 2005
    Inventors: Balachander Krishnamurthy, Subhabrata Sen, Yin Zhang, Yan Chen
  • Publication number: 20040254921
    Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.
    Type: Application
    Filed: April 13, 2004
    Publication date: December 16, 2004
    Inventors: Edith Cohen, Balachander Krishnamurthy, Jennifer Lynn Rexford
  • Patent number: 6751608
    Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: June 15, 2004
    Assignee: AT&T Corp.
    Inventors: Edith Cohen, Balachander Krishnamurthy, Jennifer Lynn Rexford
  • Patent number: 6606639
    Abstract: A method more efficiently indexes dynamic documents. The method adjusts the frequency with which dynamic documents are retrieved taking into account the extent to which the document varies between its most recent retrievals. Furthermore, the method selects portions of the document to be indexed based on the substance of the differences between recently retrieved copies.
    Type: Grant
    Filed: May 22, 2002
    Date of Patent: August 12, 2003
    Assignee: AT&T Corp.
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Patent number: 6578113
    Abstract: A proxy cache maintains a copy of multiple resources from various servers in a network. When the proxy cache must generate a validation request for at least one resource at one of the servers, the proxy cache piggybacks one or more additional cache validation requests related to documents presently stored in the cache but originating from or associated with the server in question. Upon receipt of an indication of the freshness or validity of the cached copy of the document, the proxy cache can then make a determination as to whether to request an update of the document.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: June 10, 2003
    Assignee: AT&T Corp.
    Inventors: Balachander Krishnamurthy, Craig Ellis Wills
  • Publication number: 20030061272
    Abstract: A proxy cache maintains a copy of multiple resources from various servers in a network. When the proxy cache must generate a validation request for at least one resource at one of the servers, the proxy cache piggybacks one or more additional cache validation requests related to documents presently stored in the cache but originating from or associated with the server in question. Upon receipt of an indication of the freshness or validity of the cached copy of the document, the proxy cache can then make a determination as to whether to request an update of the document.
    Type: Application
    Filed: December 30, 1997
    Publication date: March 27, 2003
    Inventors: BALACHANDER KRISHNAMURTHY, CRAIG ELLIS WILLS
  • Publication number: 20030046343
    Abstract: The present invention is a method for improving delivery of content to a client communicating with a server on the Web. Groups or clusters of clients are formed by processing the IP addresses of the clients according to a network-aware, radix-encoded trie classification process. The groups of clients are categorized based on information about one or more clients in each group that can be determined by the server. That information is used to help drive tailored actions on the part of Web servers. Users with poor connectivity may choose not to spend much time at a Web site if it takes a long time to receive a page, even if the Web server at the site is not the bottleneck. Retaining such clients may be of interest to a Web site. Better-connected clients may be able to receive enhanced representations of Web pages such as with higher quality images.
    Type: Application
    Filed: August 7, 2002
    Publication date: March 6, 2003
    Inventors: Balachander Krishnamurthy, Craig Ellis Wills
  • Publication number: 20020198961
    Abstract: The present invention is a method for improving delivery of content to a client communicating with a server on the Web. The client is categorized based on information about the client that can be determined by the server. That information is used to help drive tailored actions on the part of Web servers. Users with poor connectivity may choose not to spend much time at a Web site if it takes a long time to receive a page, even if the Web server at the site is not the bottleneck. Retaining such clients may be of interest to a Web site. Better-connected clients may be able to receive enhanced representations of Web pages such as with higher quality images.
    Type: Application
    Filed: August 7, 2002
    Publication date: December 26, 2002
    Inventors: Balachander Krishnamurthy, Craig Ellis Wills
  • Publication number: 20020138467
    Abstract: A method more efficiently indexes dynamic documents. The method adjusts the frequency with which dynamic documents are retrieved taking into account the extent to which the document varies between its most recent retrievals. Furthermore, the method selects portions of the document to be indexed based on the substance of the differences between recently retrieved copies.
    Type: Application
    Filed: May 22, 2002
    Publication date: September 26, 2002
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Patent number: 6434573
    Abstract: A method more efficiently indexes dynamic documents. The method adjusts the frequency with which dynamic documents are retrieved taking into account the extent to which the document varies between its most recent retrievals. Furthermore, the method selects portions of the document to be indexed based on the substance of the differences between recently retrieved copies.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: August 13, 2002
    Assignee: AT&T Corp.
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Patent number: 6363379
    Abstract: A method of presenting clusters of documents in response to a search query where the documents within a cluster are determined to be related to one another. This relationship is assessed by comparing documents which match one or more terms in the query to determine the extent to which the documents have commonality with respect to terms appearing infrequently in the collection of documents. As a consequence, the cluster of documents represents a response or query result that is split across multiple documents. In a further variation the cluster can be constituted by a structured document and an unstructured document.
    Type: Grant
    Filed: September 28, 2000
    Date of Patent: March 26, 2002
    Assignee: AT&T Corp.
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Patent number: 6338058
    Abstract: A method provides a more informative result to a user in connection with the search for documents in a database. In particular, the method provides augmented addresses, in the Internet environment augmented universal resource locators, which include an indication of a document attribute which may be of interest to the user. Such attributes may include an indication of the language of the document (e.g., English or Japanese) or the popularity of the document.
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: January 8, 2002
    Assignee: AT&T Corp
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Publication number: 20010056409
    Abstract: It is an object of the invention to reduce the risk of misuse of a user's credit card number while avoiding having to securely contact and authenticate with a card-issuer before each transaction. In accordance with an aspect of the invention, the card-holder/user has access to a temporary authorization number generator, which is capable of accepting data from the user, such as the user's credit card number, and generating a cryptographically-secure temporary authorization number that is used in lieu of the user's credit card number in transactions. The card-issuer need not know the temporary authorization number before receiving the request for authorization from a merchant presented with it during a transaction. The present invention, while not limited to electronic commerce transactions, is especially suited for electronic commerce transactions occurring over a telecommunication network where the user cannot trust the integrity of either the network or the merchant receiving the credit card number.
    Type: Application
    Filed: May 15, 2001
    Publication date: December 27, 2001
    Inventors: Steven Michael Bellovin, Jeffrey Korn, Balachander Krishnamurthy
  • Patent number: 6330561
    Abstract: A method and apparatus provide improved cache coherency and more effective caching operations without placing an undue burden on network links. A proxy receives a request for a resource and then, depending on information in the proxy cache, generates a resource request for transmission to a resource server. The proxy appends a proxy filter to the request. The resource server maintains one or more volumes of resources based on some predetermined criterion that can be either static or dynamic in nature. Upon receipt of the request and the proxy filter the resource server generates a request response and a piggybacked list of additional resources selected from the volume with which the requested resource is associated.
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: December 11, 2001
    Assignee: AT&T Corp.
    Inventors: Edith Cohen, Balachander Krishnamurthy, Jennifer Lynn Rexford
  • Patent number: 6167397
    Abstract: A method of presenting clusters of documents in response to a search query where the documents within a cluster are determined to be related to one another. This relationship is assessed by comparing documents which match one or more terms in the query to determine the extent to which the documents have commonality with respect to terms appearing infrequently in the collection of documents. As a consequence, the cluster of documents represents a response or query result that is split across multiple documents. In a further variation the cluster can be constituted by a structured document and an unstructured document.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: December 26, 2000
    Assignee: AT&T Corporation
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Patent number: 6134553
    Abstract: A method improves a search in a hierarchical structure by focusing the search to selected regions within the structure. The method defines one or more region-sets and uses the region-set(s) as either a filter for the results of a key-word search or an integrated part of a search engine to increase the efficiency of the search engine. The method also provides for dynamic creation of new region-sets from existing region-sets using a prescribed set of operators.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: October 17, 2000
    Assignee: AT&T Corporation
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava, Dan Suciu
  • Patent number: 6073130
    Abstract: A method enhances the presentation of search results from a structured database. In accordance with the method, a search query including two or more attribute/value pairs is presented to a system. The system then identifies a plurality of records which each minimally match the search query. Each document or record in the plurality of identified records is assigned a weight based on at least two factors: the extent to which the record matches the entire search query; and the relative frequency with which the attribute/value pair that matches the given record matches the records of the remainder of the structured database. The plurality of records that minimally match the search query are then identified to the requester in ranked order based on the assigned weights.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: June 6, 2000
    Assignee: AT&T Corp.
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava
  • Patent number: 6070157
    Abstract: A method provides a more informative result to a user in connection with the search for documents in a database. In particular, the method provides augmented addresses, in the Internet environment augmented universal resource locators, which include an indication of a document attribute which may be of interest to the user. Such attributes may include an indication of the language of the document (e.g., English or Japanese) or the popularity of the document.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: May 30, 2000
    Assignee: AT&T Corporation
    Inventors: Guy Jacobson, Balachander Krishnamurthy, Divesh Srivastava