Patents by Inventor Sitaram Dontu
Sitaram Dontu 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: 8730976Abstract: Various methods and systems for preventing erroneous link aggregation due to component relocation are disclosed. Such methods include a method for changing the identifier used by a network device and communicating the identifier change to a peer network device without disrupting an aggregated link. In one embodiment, a method involves detecting an identifier change and sending a Port Aggregation Protocol (PAgP) protocol data unit (PDU) that includes a new identifier and information. The information indicates the identifier change. The new identifier identifies a network device subsequent to the identifier change. Another embodiment of a method involves detecting an identifier change and, subsequent to the identifier change, sending a link aggregation protocol PDU that includes an “old device identifier” field dedicated to conveying an old identifier. The old identifier identifies a network device prior to the identifier change.Type: GrantFiled: August 17, 2004Date of Patent: May 20, 2014Assignee: Cisco Technology, Inc.Inventors: Sitaram Dontu, Norman W. Finn, Nelson B. D'Souza
-
Patent number: 7876764Abstract: Various systems and methods that allow multiple aggregation protocol sessions to be established in a daisy chain network are disclosed. One method involves sending a first aggregation protocol packet and a first session identifier associated therewith to a first network device via a first interface and sending a second aggregation protocol packet and a second session identifier associated therewith to a second network device via the first interface.Type: GrantFiled: October 11, 2005Date of Patent: January 25, 2011Assignee: Cisco Technology, Inc.Inventors: Stefano Binetti, Hiroshi Suzuki, Shreeram Bhide, Sitaram Dontu, Pagalavan Krishnamoorthy, Chien Fang, Norman W. Finn
-
Patent number: 7839843Abstract: A virtual network device sub-unit includes an interface to a virtual network device link and a distributed forwarding module. The interface receives a packet, and the distributed forwarding module forwards the packet received by the interface. The distributed forwarding module performs an ingress lookup if the packet includes a multicast destination address and an egress lookup if the packet includes a unicast destination address. If the packet includes a multicast destination address, the distributed forwarding module replicates the packet for each of several outgoing VLANs associated with the multicast destination address. If an additional multicast packet is received via an interface that is not coupled to a virtual network device link, the distributed forwarding module sends at most one copy of the additional multicast packet via the virtual network device link.Type: GrantFiled: April 16, 2004Date of Patent: November 23, 2010Assignee: Cisco Technology, Inc.Inventors: Sitaram Dontu, Faisal Mushtaq, Shreeram Bhide, Michael R. Smith, Ali Golshan
-
Patent number: 7706364Abstract: A virtual network device cluster includes several different virtual network device sub-units, which collectively operate as a single logical network device. The virtual network device cluster identifies the virtual network device sub-unit via which a given packet enters the virtual network device cluster. A packet is forwarded through the virtual network device cluster based on which virtual network device sub-unit has been identified for that packet. In one embodiment, a method involves receiving a packet via a first interface of a first one of several virtual network device sub-units of a virtual network device and associating the packet with the first one of the virtual network device sub-units. The method also involves inhibiting the packet from being sent via an interface of one of the virtual network device sub-units, in response to the packet being associated with the first one of the virtual network device sub-units.Type: GrantFiled: May 19, 2004Date of Patent: April 27, 2010Assignee: Cisco Technology, Inc.Inventors: Michael R. Smith, Sitaram Dontu, Faisal Mushtaq
-
Patent number: 7436836Abstract: Various methods and systems for detecting whether a network device supports a protocol, which defines a supplemental header, are disclosed. One method involves detecting a value within a preamble generated by a sending device and verifying that a header format of a header, also generated by the sending device, conforms to a header format definition of a protocol. The header format definition of the protocol defines a supplemental header. The preamble can be an Ethernet preamble. In one embodiment, the preamble is a converged data link (CDL) preamble or other type of preamble that is used to convey operation, administration and management (OAM) information.Type: GrantFiled: June 30, 2004Date of Patent: October 14, 2008Assignee: Cisco Technology, Inc.Inventors: Faisal Mushtaq, Sitaram Dontu, Shreeram Bhide, Ali Golshan, Michael R. Smith
-
Publication number: 20070081557Abstract: Various systems and methods that allow multiple aggregation protocol sessions to be established in a daisy chain network are disclosed. One method involves sending a first aggregation protocol packet and a first session identifier associated therewith to a first network device via a first interface and sending a second aggregation protocol packet and a second session identifier associated therewith to a second network device via the first interface.Type: ApplicationFiled: October 11, 2005Publication date: April 12, 2007Inventors: Stefano Binetti, Hiroshi Suzuki, Shreeram Bhide, Sitaram Dontu, Pagalavan Krishnamoorthy, Chien Fang, Norman Finn
-
Patent number: 7178052Abstract: Method and devices are provided for implementing high availability. Some implementations provide high availability for virtual switches of data networks. Each virtual switch acts as a single logical unit, while encompassing at least two physical chassis, referred to herein as a master chassis and a slave chassis. In some preferred embodiments, the active supervisor in the master chassis is configured as an active supervisor of the virtual switch and the active supervisor in the slave chassis is configured as the standby supervisor of the virtual switch.Type: GrantFiled: September 18, 2003Date of Patent: February 13, 2007Assignee: Cisco Technology, Inc.Inventors: Hemant Hebbar, Sitaram Dontu, Madhuri Kolli
-
Publication number: 20060039384Abstract: Various methods and systems for preventing erroneous link aggregation due to component relocation are disclosed. Such methods include a method for changing the identifier used by a network device and communicating the identifier change to a peer network device without disrupting an aggregated link. In one embodiment, a method involves detecting an identifier change and sending a Port Aggregation Protocol (PAgP) protocol data unit (PDU) that includes a new identifier and information. The information indicates the identifier change. The new identifier identifies a network device subsequent to the identifier change. Another embodiment of a method involves detecting an identifier change and, subsequent to the identifier change, sending a link aggregation protocol PDU that includes an “old device identifier” field dedicated to conveying an old identifier. The old identifier identifies a network device prior to the identifier change.Type: ApplicationFiled: August 17, 2004Publication date: February 23, 2006Inventors: Sitaram Dontu, Norman Finn, Nelson D'Souza
-
Publication number: 20060002299Abstract: Various methods and systems for detecting whether a network device supports a protocol, which defines a supplemental header, are disclosed. One method involves detecting a value within a preamble generated by a sending device and verifying that a header format of a header, also generated by the sending device, conforms to a header format definition of a protocol. The header format definition of the protocol defines a supplemental header. The preamble can be an Ethernet preamble. In one embodiment, the preamble is a converged data link (CDL) preamble or other type of preamble that is used to convey operation, administration and management (OAM) information.Type: ApplicationFiled: June 30, 2004Publication date: January 5, 2006Inventors: Faisal Mushtaq, Sitaram Dontu, Shreeram Bhide, Ali Golshan, Michael Smith
-
Publication number: 20050259646Abstract: A virtual network device cluster includes several different virtual network device sub-units, which collectively operate as a single logical network device. The virtual network device cluster identifies the virtual network device sub-unit via which a given packet enters the virtual network device cluster. A packet is forwarded through the virtual network device cluster based on which virtual network device sub-unit has been identified for that packet. In one embodiment, a method involves receiving a packet via a first interface of a first one of several virtual network device sub-units of a virtual network device and associating the packet with the first one of the virtual network device sub-units. The method also involves inhibiting the packet from being sent via an interface of one of the virtual network device sub-units, in response to the packet being associated with the first one of the virtual network device sub-units.Type: ApplicationFiled: May 19, 2004Publication date: November 24, 2005Inventors: Michael Smith, Sitaram Dontu, Faisal Mushtaq
-
Publication number: 20050163115Abstract: A virtual network device sub-unit includes an interface to a virtual network device link and a distributed forwarding module. The interface receives a packet, and the distributed forwarding module forwards the packet received by the interface. The distributed forwarding module performs an ingress lookup if the packet includes a multicast destination address and an egress lookup if the packet includes a unicast destination address. If the packet includes a multicast destination address, the distributed forwarding module replicates the packet for each of several outgoing VLANs associated with the multicast destination address. If an additional multicast packet is received via an interface that is not coupled to a virtual network device link, the distributed forwarding module sends at most one copy of the additional multicast packet via the virtual network device link.Type: ApplicationFiled: April 16, 2004Publication date: July 28, 2005Inventors: Sitaram Dontu, Faisal Mushtaq, Shreeram Bhide, Michael Smith, Ali Golshan
-
Publication number: 20050066216Abstract: Method and devices are provided for implementing high availability. Some implementations provide high availability for virtual switches of data networks. Each virtual switch acts as a single logical unit, while encompassing at least two physical chassis, referred to herein as a master chassis and a slave chassis. In some preferred embodiments, the active supervisor in the master chassis is configured as an active supervisor of the virtual switch and the active supervisor in the slave chassis is configured as the standby supervisor of the virtual switch.Type: ApplicationFiled: September 18, 2003Publication date: March 24, 2005Applicant: Cisco Technology, Inc.Inventors: Hemant Hebbar, Sitaram Dontu, Madhuri Kolli