Patents by Inventor Muralidharan Kodialam

Muralidharan Kodialam 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).

  • Publication number: 20070237081
    Abstract: The invention includes a method and apparatus for generating a link transmission schedule for handling traffic variation in wireless networks without dynamic scheduling or routing. The method includes determining fixed traffic capacities associated with respective wireless links of a wireless network according to a routing algorithm, and generating, using the routing algorithm and the fixed traffic capacities, a link transmission schedule including at least one condition by which traffic is transmitted using each of the network links. The link transmission schedule is adapted to remain substantially fixed during dynamic traffic changes. The routing algorithm may be a two-phase routing algorithm in which traffic is distributed by each node in the wireless network to every node in the wireless network using traffic split ratios.
    Type: Application
    Filed: March 30, 2006
    Publication date: October 11, 2007
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20070211635
    Abstract: The invention includes a method and apparatus for determining a coincidence count associated with a traffic flow in a network. The method includes receiving a first packet having a first flow identifier associated with one of the traffic flows, comparing the first flow identifier of the first packet to each of a plurality of other flow identifiers associated with a respective plurality of other packets, and determining a coincidence count associated with the first flow identifier based on the comparison of the first flow identifier to each of the plurality of other flow identifiers. The method for determining a coincidence count associated with one of a plurality of traffic flows may be extended for determining respective coincidence counts associated with a plurality of traffic flows. The determined coincidence counts may be used for determining at least one traffic flow statistic.
    Type: Application
    Filed: March 10, 2006
    Publication date: September 13, 2007
    Inventors: Fang Hao, Muralidharan Kodialam, Tirunell Lakshman, Hui Zhang
  • Publication number: 20070211647
    Abstract: The invention includes a method and apparatus for generating a coincidence count table adapted for determining at least one flow statistic. The method includes receiving a plurality of packets comprising a respective plurality of payloads, comparing payloads associated with consecutive ones of the plurality of packets for identifying at least one simple pattern included within the compared payloads of the consecutive ones of the plurality of packets, for each of the consecutive ones of the plurality of packets, if the at least one simple pattern is identified, processing the at least one simple pattern to form a complex pattern, and for each complex pattern, updating a coincidence count associated with the complex pattern, wherein the coincidence counts are adapted for determining at least one flow statistic.
    Type: Application
    Filed: March 10, 2006
    Publication date: September 13, 2007
    Inventors: Fang Hao, Muralidharan Kodialam, Tirunell Lakshman, Hui Zhang
  • Publication number: 20070147248
    Abstract: A method of characterizing a capacity region in a multi-channel, multi-radio mesh network of nodes interconnected by links. The method includes: (a) modeling the network by determining one or more link-flow feasibility constraints; (b) obtaining a feasible upper-capacity bound by solving an optimization problem using the one or more link-flow feasibility constraints as necessary conditions; and (c) using an algorithm adapted to provide a feasible lower-capacity bound by (i) receiving the solution to the optimization problem as input, (ii) allocating channels to links to meet a demand vector that satisfies the one or more link-flow feasibility constraints, and (iii) scheduling flows along the allocated channels. The upper- and lower-capacity bounds define the capacity region.
    Type: Application
    Filed: December 22, 2005
    Publication date: June 28, 2007
    Inventors: Muralidharan Kodialam, Thyagarajan Nandagopal
  • Publication number: 20070025364
    Abstract: A method of routing data from a source node to a destination node in a multi-hop network of nodes interconnected by links comprises: (a) determining that a link-flow vector satisfies one or more necessary scheduling conditions for achievability, wherein the link-flow vector represents a set of flows to be routed on one or more links from the source node to the destination node; (b) generating a scheduling multi-graph for the network, wherein the scheduling multi-graph comprises a graph having at least one pair of nodes with multiple edges therebetween; (c) deriving one or more sufficient scheduling conditions for achievability of the link-flow vector by edge-coloring the scheduling multi-graph; (d) solving a linear optimization problem over the one or more necessary scheduling conditions to obtain an upper bound on the achievability of the link-flow vector; (e) generating, based on the scheduling multi-graph, a solution comprising a set of routes and an associated schedule for achieving the link-flow vector,
    Type: Application
    Filed: August 1, 2005
    Publication date: February 1, 2007
    Inventors: Muralidharan Kodialam, Thyagarajan Nandagopal
  • Publication number: 20060221855
    Abstract: A method for measuring flow is disclosed. The method includes receiving an IP packet; determining if another IP packet is stored in a register; if another IP packet is stored in the register, comparing the stored IP packet with the received IP packet; and determining the longest match between the stored IP packet and the received IP packet.
    Type: Application
    Filed: March 31, 2005
    Publication date: October 5, 2006
    Inventors: Fang Hao, Muralidharan Kodialam, Tirunell Lakshman
  • Publication number: 20060067331
    Abstract: The invention comprises a method for routing traffic from a first node towards a plurality of intermediate nodes according to respective traffic weighting factors associated with the plurality of intermediate nodes.
    Type: Application
    Filed: September 27, 2004
    Publication date: March 30, 2006
    Inventors: Muralidharan Kodialam, Tirunell Lakshman
  • Publication number: 20050270985
    Abstract: A method of estimating per-flow traffic in a network of nodes interconnected by links splits the incoming traffic stream to a node into a number of parallel sub-streams by flow assignment using a hash function. Since each flow in the incoming traffic stream constitutes a larger fraction of the traffic in its sub-stream, the probability of obtaining two-runs increases. The number of two-runs per flow is then employed to generate an estimate of the traffic of the flow.
    Type: Application
    Filed: September 22, 2004
    Publication date: December 8, 2005
    Inventors: Fang Hao, Muralidharan Kodialam, Tirunell Lakshman
  • Publication number: 20050270984
    Abstract: A method of estimating per-flow traffic in a network of nodes interconnected by links samples an incoming traffic stream to a node. A sampling interval is derived based on a desired level of accuracy. The number of two-run occurrences for each flow is tracked in the sample stream. The number of two-runs per flow is then employed to generate an estimate of the traffic of the flow.
    Type: Application
    Filed: September 22, 2004
    Publication date: December 8, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman
  • Publication number: 20050270972
    Abstract: A method for supporting recovery from failure of a path in a network of nodes interconnected by links comprises: (a) selecting an intermediate node between an ingress point and an egress point of the network, wherein the intermediate node minimizes the sum of (i) a capacity constraint between the ingress point and the intermediate node and (ii) a capacity constraint between the intermediate node and the egress point; wherein the selection identifies a first link-disjoint path set between the ingress point and the intermediate node, and a second link-disjoint path set between the intermediate node and the egress point, each link-disjoint path set comprising a backup path and at least one primary path; (b) implementing, during a first routing phase, a first routing method for routing a fraction of a service level between the ingress point and the intermediate node along each of the one or more primary paths of the first link-disjoint path set; and (c) implementing, during a second routing phase, a second routin
    Type: Application
    Filed: May 31, 2005
    Publication date: December 8, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20050271060
    Abstract: A method for supporting recovery from failure of a link in a network of nodes interconnected by links comprises: (a) selecting an intermediate node between an ingress point and an egress point of the network, wherein the intermediate node minimizes the sum of (i) a capacity constraint between the ingress point and the intermediate node and (ii) a capacity constraint between the intermediate node and the egress point; wherein the selection identifies a first path structure between the ingress point and the intermediate node, and a second path structure between the intermediate node and the egress point, each path structure comprising a primary path and one or more link backup detours protecting each link on the primary path; (b) implementing, during a first routing phase, a first routing method for routing a fraction of a service level between the ingress point and the intermediate node along the primary path of the first path structure; and (c) implementing, during a second routing phase, a second routing met
    Type: Application
    Filed: May 31, 2005
    Publication date: December 8, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20050265258
    Abstract: A scheme for a carrier to route one or more packets of traffic to their destination after ensuring that they pass through a pre-determined intermediate node also in the carrier's domain permits the carrier to handle all permissible traffic patterns without knowledge of the traffic matrix, subject to edge-link capacity constraints.
    Type: Application
    Filed: April 14, 2005
    Publication date: December 1, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20050265255
    Abstract: A method for supporting recovery from failure of a node in a network of nodes interconnected by links, wherein the failed node is in a path providing a service level between an ingress point and an egress point of the network, comprises: (a) selecting a set of one or more intermediate nodes between the ingress point and the egress point, the set excluding the failed node; (b) determining, based on available bandwidth of the network, a non-zero fraction of the service level to route from the ingress point to each intermediate node; (c) implementing, during a first routing phase, a first routing method to determine one or more paths from the ingress point to each intermediate node for routing the corresponding fraction of the service level; and (d) implementing, during a second routing phase, a second routing method to determine one or more paths from each intermediate node to the egress point for routing the corresponding fraction of the service level.
    Type: Application
    Filed: May 31, 2005
    Publication date: December 1, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20050259648
    Abstract: A network of nodes interconnected by links has content filtering specified at certain nodes, and routing of packet connections through the network is generated based on the specified content-filtering nodes. The network is specified via a content-filtering node placement method and a network-capacity maximization method so as to apply content filtering to packets for substantially all traffic (packet streams) carried by the network.
    Type: Application
    Filed: May 21, 2004
    Publication date: November 24, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20050226214
    Abstract: A network of nodes interconnected by links, such as a wavelength division multiplexing (WDM) ring network, is modeled by a delayed graph in which propagation delay between nodes is accounted for. Given the delayed graph, a traffic matrix for an admissible traffic pattern is scheduled over a frame period. Scheduling of the traffic matrix formulates a set of scheduling constraints based on the delays and decomposes the traffic matrix into a set of transmission matrices. Each of the set of transmission matrices is scheduled over the frame period.
    Type: Application
    Filed: April 8, 2004
    Publication date: October 13, 2005
    Inventors: Isaac Keslassy, Muralidharan Kodialam, Tirunell Lakshman, Dimitrios Stiliadis
  • Publication number: 20050220023
    Abstract: We formulate the network-wide traffic measurement/analysis problem as a series of set-cardinality-determination (SCD) problems. By leveraging recent advances in probabilistic distinct sample counting techniques, the set-cardinalities, and thus, the network-wide traffic measurements of interest can be computed in a distributed manner via the exchange of extremely light-weight traffic digests (TD's) amongst the network nodes, i.e. the routers. A TD for N packets only requires O(loglog N) bits of memory storage. The computation of such O(loglog N)-sized TD is also amenable for efficient hardware implementation at wire-speed of 10 Gbps and beyond. Given the small size of the TD's, it is possible to distribute nodal TD's to all routers within a domain by piggybacking them as opaque data objects inside existing control messages, such as OSPF link-state packets (LSPs) or I-BGP control messages.
    Type: Application
    Filed: August 2, 2004
    Publication date: October 6, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Wing Lau
  • Publication number: 20050174934
    Abstract: A given network of nodes that are interconnected by links having corresponding capacities has each link's capacity divided into working capacity and restoration capacity without a priori information about network traffic characteristics. Allocation of working capacity and restoration capacity for the network might be optimized by characterization of the network in accordance with a linear programming problem (LPP) subject to network constraints and then generating a solution to the LPP either exactly or with an approximation. Partitioning the capacity of each link in the network into working and restoration capacities minimizes the restoration capacity overhead in the network to allow for higher network utilization.
    Type: Application
    Filed: February 11, 2004
    Publication date: August 11, 2005
    Inventors: Muralidharan Kodialam, Tirunell Lakshman, Sudipta Sengupta
  • Publication number: 20050147031
    Abstract: A fast and efficient method for network re-optimization is described. In one embodiment, the technique uses an algorithm that requires limited aggregate information to continually monitor the network for re-optimization opportunities. The re-optimization of the present invention enables a network to accommodate more traffic without adding capacity. The re-optimization of the present invention is performed only when network efficiency benefits above a predetermined threshold may be obtained. In addition, a least-cost set of sessions is determined to perform the re-routing of the present invention to attain the desired network efficiency.
    Type: Application
    Filed: January 7, 2004
    Publication date: July 7, 2005
    Inventors: Randeep Bhatia, Muralidharan Kodialam, Tirunell Lakshman
  • Patent number: 5923742
    Abstract: A system and method for detecting mass addressing events comprising a first register, a second register, a first counter, and a second counter is disclosed. Potential mass addressing events are detected by comparing a most recently selected address to the contents of the first register and incrementing the first counter if they are equal, or loading the most recently selected address into the first register and initializing the first counter if they are unequal. If the first counter's count reaches a first count threshold, the contents of the first register are compared to the contents of the second register and the second counter is incremented if they are equal, or, if they are unequal, the contents of the first register are loaded into the second register and the second counter is initialized. If the second counter's count reaches a second count threshold, an alarm is issued.
    Type: Grant
    Filed: February 14, 1997
    Date of Patent: July 13, 1999
    Assignee: AT&T Grp.
    Inventors: Muralidharan Kodialam, Donald Jay Mintz
  • Patent number: 5864611
    Abstract: A system and method for estimating the traffic rates of large traffic sources is provided. A class of a most recently selected address is compared to the contents of a register. If the class is the same as the contents of the register, a first counter is incremented; otherwise, the class is loaded into the register and the first counter is initialized. A class of a new most recently selected address is then obtained and the above process repeated. If the count of the first counter reaches a predetermined threshold, a threshold counter associated with the class is incremented and the first counter and register are reset. A different threshold counter is associated with each different class. After a predetermined time period, the traffic rate for a class may be computed from the count of the threshold counter associated with the class.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: January 26, 1999
    Assignee: AT&T Corp.
    Inventors: Chee Ching, Salomon Leo Ehrenreich, Muralidharan Kodialam, Donald Jay Mintz