Patents by Inventor Krishnamurthy Subramanian

Krishnamurthy Subramanian 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: 8014278
    Abstract: A packet network device has multiple equal output paths for at least some traffic flows. The device adjusts load between the paths using a structure that has more entries than the number of equal output paths, with at least some of the output paths appearing as entries in the structure more than once. By adjusting the frequency and/or order of the entries, the device can effect changes in the portion of the traffic flows directed to each of the equal output paths. Other embodiments are described and claimed.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: September 6, 2011
    Assignee: Force 10 Networks, Inc
    Inventors: Krishnamurthy Subramanian, Eddie Tan, Rajeev Manur
  • Patent number: 7957391
    Abstract: A physical layer device distributes a high-speed packet data stream to multiple lower-speed physical channels, and reverses the process to receive a high-speed packet data stream that has been distributed across multiple lower-speed physical channels. The packet data is distributed by removing interpacket gap characters from between packets and using a different control character to delineate packets. Interpacket gap characters can then be used to delineate equal-length frames distributed to each of the multiple physical channels. Each frame consists of a concatenation of fixed-size blocks of packet data. By selecting a frame size larger than the average packet size, overhead on the multiple physical channels can actually be lower than the overhead on the single high-speed channel, allowing the aggregation to achieve line rate operation at the high-speed rate.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: June 7, 2011
    Assignee: Force 10 Networks, Inc
    Inventor: Krishnamurthy Subramanian
  • Patent number: 7949134
    Abstract: In one embodiment, a hybrid backplane coding scheme transmits data using lengthy sequences of scrambled data, separated by 8b/10b control character sequences that prepare the receiver for the next scrambled sequence and permit realignment if necessary. Several lanes are coded separately in this manner, and then multiplexed on a common channel. Alignment sequences in the control character sequences, as well as scrambler seeds, are set to avoid synchronization of patterns generated among all lanes, which would tend to confuse a receiving serdes and/or phase-locked loop that recovers timing from the multiplexed scrambled signals.
    Type: Grant
    Filed: October 17, 2007
    Date of Patent: May 24, 2011
    Assignee: Force 10 Networks, Inc.
    Inventors: Joel Goergen, Krishnamurthy Subramanian, Ann Gui
  • Patent number: 7903554
    Abstract: Traffic engineering using a label-switching protocol is enhanced for label-switched paths that traverse a logical link that is an aggregation of component links. In one embodiment, a label edge router is provided with information regarding the bandwidth capabilities and loading of the component links of a LAG. The label edge router is then allowed to set up paths that traverse a specific component link of a LAG, and reserve bandwidth on such a component link. Other traffic may continue to be distributed across the LAG membership.
    Type: Grant
    Filed: April 4, 2008
    Date of Patent: March 8, 2011
    Assignee: Force 10 Networks, Inc.
    Inventors: Rajeev Manur, Krishnamurthy Subramanian, Vishal Zinjuvadia
  • Patent number: 7843830
    Abstract: Apparatus and methods for epoch retransmission in a packet network device are described. In at least one embodiment, epoch receivers check received epoch data for errors. When an error is detected, a receiver is allowed to request that the entire epoch be retransmitted. All epoch senders retain transmitted epoch data until the time for requesting a retransmission of that data is past. If retransmission is requested by any receiver, the epoch is “replayed.” This approach mitigates the problem of dropping multiple packets (bundled in a large epoch) due to an intraswitch error with the epoch. Other embodiments are also described and claimed.
    Type: Grant
    Filed: May 5, 2005
    Date of Patent: November 30, 2010
    Assignee: Force 10 Networks, Inc
    Inventors: Krishnamurthy Subramanian, Heeloo Chung, Glenn Poole
  • Publication number: 20090034728
    Abstract: In one embodiment, a hybrid backplane coding scheme transmits data using lengthy sequences of scrambled data, separated by 8b/10b control character sequences that prepare the receiver for the next scrambled sequence and permit realignment if necessary. Several lanes are coded separately in this manner, and then multiplexed on a common channel. Alignment sequences in the control character sequences, as well as scrambler seeds, are set to avoid synchronization of patterns generated among all lanes, which would tend to confuse a receiving serdes and/or phase-locked loop that recovers timing from the multiplexed scrambled signals.
    Type: Application
    Filed: October 17, 2007
    Publication date: February 5, 2009
    Applicant: Force10 Networks, Inc.
    Inventors: Joel Goergen, Krishnamurthy Subramanian, Ann Gui
  • Patent number: 7190696
    Abstract: A network-processor device comprises a packet-processor for an ingress port that is operative to distribute data flows to a plurality of equal-cost paths for transfer of data toward a given destination. The packet-processor also includes further distribution circuitry for designating a link of a link aggregation by which to channel the data between routers within a part of a selected path. Accordingly, each of the layer distributions—i.e., amongst the higher-level equal-cost-paths and amongst the lower-level link aggregation—are capable of being coordinated by a common, generic packet-processor.
    Type: Grant
    Filed: March 5, 2002
    Date of Patent: March 13, 2007
    Assignee: Force10 Networks, Inc.
    Inventors: Rajeev Manur, Krishnamurthy Subramanian, Tissa Senevirathne