Patents by Inventor David R. Cheriton

David R. Cheriton 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: 20130024645
    Abstract: Intercepting a requested memory operation corresponding to a conventional memory is disclosed. The requested memory operation is translated to be applied to a structured memory.
    Type: Application
    Filed: May 20, 2010
    Publication date: January 24, 2013
    Applicant: HICAMP SYSTEMS, INC.
    Inventors: David R. Cheriton, Alexandre Y. Solomatnikov
  • Publication number: 20120265931
    Abstract: Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.
    Type: Application
    Filed: June 26, 2012
    Publication date: October 18, 2012
    Applicant: HICAMP SYSTEMS, INC.
    Inventor: David R. Cheriton
  • Publication number: 20120260238
    Abstract: A method is provided for translating sets of constraint declarations to imperative code sequences based on defining an instantiatable object per set, inserting calls to a notification callback mechanism on state modification and defining calls in the constraint context as imperative code sequences that, in response to these callbacks, take actions to maintain these constraints. This notification and callback mechanism can also be employed in connection with external events, thereby providing for efficient implementation of event-sequenced imperative procedures in a constraint programming language.
    Type: Application
    Filed: June 12, 2012
    Publication date: October 11, 2012
    Inventor: David R. Cheriton
  • Patent number: 8230168
    Abstract: Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.
    Type: Grant
    Filed: October 11, 2011
    Date of Patent: July 24, 2012
    Assignee: Hicamp Systems, Inc.
    Inventor: David R. Cheriton
  • Patent number: 8214795
    Abstract: A method is provided for translating sets of constraint declarations to imperative code sequences based on defining an instantiatable object per set, inserting calls to a notification callback mechanism on state modification and defining calls in the constraint context as imperative code sequences that, in response to these callbacks, take actions to maintain these constraints. This notification and callback mechanism can also be employed in connection with external events, thereby providing for efficient implementation of event-sequenced imperative procedures in a constraint programming language.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: July 3, 2012
    Assignee: OptumSoft, Inc.
    Inventor: David R. Cheriton
  • Publication number: 20120131643
    Abstract: A method for providing security groups based on the use of tunneling is disclosed. The method includes assigning a security group identifier (SGI) to a packet and classifying the packet based on the packet's SGI.
    Type: Application
    Filed: January 31, 2012
    Publication date: May 24, 2012
    Inventor: David R. Cheriton
  • Publication number: 20120096221
    Abstract: Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.
    Type: Application
    Filed: October 11, 2011
    Publication date: April 19, 2012
    Applicant: Hicamp Systems, Inc.
    Inventor: David R. Cheriton
  • Patent number: 8146148
    Abstract: A method for providing security groups based on the use of tunneling is disclosed. The method includes assigning a security group identifier (SGI) to a packet and classifying the packet based on the packet's SGI.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: March 27, 2012
    Assignee: Cisco Technology, Inc.
    Inventor: David R. Cheriton
  • Patent number: 8065476
    Abstract: Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.
    Type: Grant
    Filed: December 17, 2009
    Date of Patent: November 22, 2011
    Assignee: Hicamp Systems, Inc.
    Inventor: David R. Cheriton
  • Patent number: 8064451
    Abstract: A method for using network address translation in switches and routers to define a virtual host as the source of a multicast channel within a single-source multicast model and to translate packet addresses from different multicast sources so that the packets appear to be originating from the virtual host. Address-translated packets are thus forwarded through a single-source multicast channel and received by the subscribing host(s)/clients as though the packets came from a single “virtual” source. This methodology can be used to map two or more sources simultaneously onto the same multicast channel. Such a mapping is useful, for example, to present multiple views of a sporting event video broadcast, provide advertisement insertion capability, or to support transparent fail-over to a backup video source in a critical multicast application. Subscribing client hosts in the multicast reception group simply subscribe to the single virtual host as the source of a multicast channel.
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: November 22, 2011
    Assignee: Cisco Technology, Inc.
    Inventor: David R. Cheriton
  • Patent number: 7953088
    Abstract: In one embodiment, a method for processing a packet is disclosed. The method includes classifying the packet and determining an action to be taken with regard to the packet. Classifying the packet includes using information in the packet to perform the classification. The determination made as to the action to be taken with regard to the packet is based on the classifying that is performed, and is performed using a plurality of rules. At least one of the rules is configurable. The information in the packet is related to time-to-live (TTL) data corresponding to the packet.
    Type: Grant
    Filed: June 10, 2003
    Date of Patent: May 31, 2011
    Assignee: Cisco Technology, Inc.
    Inventors: David R. Cheriton, Fusun Ertemalp
  • Patent number: 7921422
    Abstract: A scheduling mechanism that fairly allocates a resource to a number of schedulable elements, of which some are latency-sensitive, is disclosed. Each element's use of the resource is tracked by determining the element's virtual time. An active element is selected from the elements that are ready to use the resource by determining the element that has the smallest effective virtual time. The effective virtual time is the element's actual virtual time modified by a borrowed virtual time value. When an element has a short-term need for the resource, it can borrow the privilege to run by borrowing virtual time. As the element uses the resource, it consumes virtual time according to its weight. When the elements are scheduled for the resource, the ready element having the smallest virtual time is selected. The invention enforces long-term fairness to each element while allowing latency-sensitive elements to be preferably selected.
    Type: Grant
    Filed: June 20, 2006
    Date of Patent: April 5, 2011
    Assignee: Cisco Technology, Inc.
    Inventors: Kenneth J. Duda, David R. Cheriton
  • Patent number: 7900251
    Abstract: A logging module is disclosed. A communications device can include, and so be made secure through the use of, the logging module. The logging module is configured to communicate information regarding a change to a configuration of a subsystem of the communications device.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: March 1, 2011
    Assignee: Cisco Technology, Inc.
    Inventor: David R. Cheriton
  • Publication number: 20110010347
    Abstract: Loading data from a computer memory system is disclosed. A memory system is provided, wherein some or all data stored in the memory system is organized as one or more pointer-linked data structures. One or more iterator registers are provided. A first pointer chain is loaded, having two or more pointers leading to a first element of a selected pointer-linked data structure to a selected iterator register. A second pointer chain is loaded, having two or more pointers leading to a second element of the selected pointer-linked data structure to the selected iterator register. The loading of the second pointer chain reuses portions of the first pointer chain that are common with the second pointer chain. Modifying data stored in a computer memory system is disclosed. A memory system is provided. One or more iterator registers are provided, wherein the iterator registers each include two or more pointer fields for storing two or more pointers that form a pointer chain leading to a data element.
    Type: Application
    Filed: July 23, 2010
    Publication date: January 13, 2011
    Applicant: Hicamp Systems, Inc.
    Inventors: David R. Cheriton, Amin Firoozshahian, Alexandre Y. Solomatnikov
  • Publication number: 20100251224
    Abstract: A programming language is extended to have embedded interpretive types (EIT) that define objects and variables to be resolved at translation time. A variable or data element having a type that is one of the EITs is referred to as an embedded interpretive variable (EIV). A control construct containing an EIV is interpreted (i.e. executed) at translation time.
    Type: Application
    Filed: March 27, 2009
    Publication date: September 30, 2010
    Inventor: David R. Cheriton
  • Patent number: 7782774
    Abstract: An extension to the conventional single rate microflow policer that provides dual rate policing with a minimum of extra resource utilization. Using the extended microflow policer, an aggressive TCP flow ramps up to exceed the policer rate, setting a burst drop flag. Once the flow rate exceeds the burst rate, a single packet is dropped and the burst drop flag is cleared. On seeing the single packet drop, the TCP sender is then expected to reduce its rate. Flows that do not back off will eventually exceed a higher, hard drop threshold and experience packet drop. An aggressive TCP rate thus oscillate around the burst rate, efficiently approaching the hard drop rate without exceeding it. The addition of only a single bit flag avoids the cost of a dual-rate policer and the tail drop behavior induced by a single rate policer.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: August 24, 2010
    Assignee: Cisco Technology, Inc.
    Inventor: David R. Cheriton
  • Patent number: 7760636
    Abstract: A system includes a network tunnel, an ingress network device coupled to send packets via the network tunnel, and an egress network device coupled to receive packets sent via the network tunnel. The egress network device is configured to provide information to the ingress network device. The information indicates whether a packet transmitted from the ingress network device to the egress network device was dropped in the network tunnel. The ingress network device can retransmit the packet to the egress network device if the packet is dropped in the network tunnel.
    Type: Grant
    Filed: January 26, 2004
    Date of Patent: July 20, 2010
    Assignee: Cisco Technology, Inc.
    Inventor: David R. Cheriton
  • Patent number: 7734811
    Abstract: The present invention describes a method and an apparatus of multi-feature lookup process using multi-feature classification memory (“CM”). In one embodiment of the present invention, the method defines various features, offered in the router, into a feature hierarchy. Individual associated CMs are merged into a combined associated multi-feature CM. The feature rules for packet processing are merged according to the feature hierarchy and the multi-feature CM is populated with the merged rules. The multi-feature CM includes combined packet-processing rules for multiple features. The multi-feature CM eliminates the need for individual associated CMs. The memory space in the multi-feature CM is shared by various feature rules.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: June 8, 2010
    Assignee: Cisco Technology, Inc.
    Inventor: David R. Cheriton
  • Publication number: 20100131936
    Abstract: A method is provided for translating sets of constraint declarations to imperative code sequences based on defining an instantiatable object per set, inserting calls to a notification callback mechanism on state modification and defining calls in the constraint context as imperative code sequences that, in response to these callbacks, take actions to maintain these constraints. This notification and callback mechanism can also be employed in connection with external events, thereby providing for efficient implementation of event-sequenced imperative procedures in a constraint programming language.
    Type: Application
    Filed: November 26, 2008
    Publication date: May 27, 2010
    Inventor: David R. Cheriton
  • Publication number: 20100100673
    Abstract: Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.
    Type: Application
    Filed: December 17, 2009
    Publication date: April 22, 2010
    Inventor: David R. Cheriton