Patents by Inventor Dinesh Mohan

Dinesh Mohan 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: 20110164502
    Abstract: Maintenance entities may be defined between customer and provider flow points to allow performance management to take place on an Ethernet network. The maintenance entities may be defined for access link, intra-domain, and inter-domain, and may be defined on a link or service basis. The maintenance entities may be used to monitor performance within a network or across networks, and may be used to monitor various performance parameters, such as frame loss, frame delay, frame delay variation, availability, errored frame seconds, service status, frame throughput, the number of frames transmitted, received or dropped, the status of a loopback interface, the amount of time a service has been unavailable, and many other parameters. Several management mechanisms may be used, and the measurements may be collected using a solicited collection method, in which a response is required and collected, or an unsolicited collection method in which a response is not required.
    Type: Application
    Filed: March 14, 2011
    Publication date: July 7, 2011
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, Marc Holness
  • Patent number: 7924725
    Abstract: Maintenance entities may be defined between customer or provider flow points for performance management on an Ethernet network. The maintenance entities may be defined for access link, intra-domain, and inter-domain, and may be defined on a link or service basis. The maintenance entities may be used to monitor performance within a network or across networks, and may be used to monitor various performance parameters, such as frame loss, frame delay, frame delay variation, availability, errored frame seconds, service status, frame throughput, the number of frames transmitted, received or dropped, the status of a loopback interface and/or the amount of time a service has been unavailable. Several management mechanisms may be used, and the measurements may be collected using a solicited collection method, in which a responses are required and collected, or an unsolicited collection method in which a response is not required.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: April 12, 2011
    Assignee: Nortel Networks Limited
    Inventors: Dinesh Mohan, Marc Holness
  • Publication number: 20110058483
    Abstract: Described is a process and system for providing an extensible forwarding plane data communications channel adapted to selectively support operations, administration and maintenance (OAM) activity within one or more different domains of an Ethernet transport network. The data communication channel is established using Ethernet protocol data units forwarded within the forwarding plane, between network elements. The Ethernet protocol data units can be Ethernet OAM frames modified to include an OpCode indicative of a maintenance communication channel. The OAM frames are generated at a selected one of the network elements (source), forwarded along the same network path as the Ethernet frames, and terminate at another network element (destination) associated with a maintenance level identified within the OAM frame. The source and destination network elements can reside on a domain boundary using the Ethernet OAM frames flowing therebetween to relay maintenance communications channel messages.
    Type: Application
    Filed: September 21, 2010
    Publication date: March 10, 2011
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, David Allan
  • Patent number: 7898965
    Abstract: Network and performance monitoring in a link state protocol controlled Ethernet network. A first node receives a network layer monitoring command from a network layer monitoring requestor. The monitoring command is directed to a second node. The first node resolves the network layer monitoring command into one or more Ethernet OAM command(s); The first node sends the Ethernet OAM command(s) to the second node, receives the results of the Ethernet OAM command(s) from the second node; and returns the results of the Ethernet OAM command(s) in the form of a network layer response to the network layer monitoring requestor. Furthermore, network layer monitoring commands may be one or more performance monitoring commands, and the Ethernet OAM commands can include Y.1731 commands. An IP flow can be adjusted between the first node and the second node in response to the network layer response returned to the network layer monitoring requestor.
    Type: Grant
    Filed: October 12, 2008
    Date of Patent: March 1, 2011
    Assignee: Nortel Networks Limited
    Inventors: Dinesh Mohan, Paul Unbehagen, Srikanth Keesara
  • Patent number: 7821949
    Abstract: Described is a process and system for providing an extensible forwarding plane data communications channel adapted to selectively support operations, administration and maintenance (OAM) activity within one or more different domains of an Ethernet transport network. The data communication channel is established using Ethernet protocol data units forwarded within the forwarding plane, between network elements. The Ethernet protocol data units can be Ethernet OAM frames modified to include an OpCode indicative of a maintenance communication channel. The OAM frames are generated at a selected one of the network elements (source), forwarded along the same network path as the Ethernet frames, and terminate at another network element (destination) associated with a maintenance level identified within the OAM frame. The source and destination network elements can reside on a domain boundary using the Ethernet OAM frames flowing therebetween to relay maintenance communications channel messages.
    Type: Grant
    Filed: September 12, 2006
    Date of Patent: October 26, 2010
    Assignee: Nortel Networks Limited
    Inventors: Dinesh Mohan, David Allan
  • Publication number: 20100226376
    Abstract: Frames of customer traffic may be encapsulated by adding Mac-in-Mac (MiM) encapsulation fields for transportation of the frames over a portion of provider network. The MiM encapsulated traffic may be further encapsulated using VPLS by adding VPLS encapsulation fields for transportation of the frames over another portion of the provider network. The MiM encapsulations use provider network MAC addresses which enables VPLS MAC learning to occur using provider network MAC address space. MiM tunnels are mapped to VPLS service instances which are assigned pseudowire tags for transportation over the VPLS portion of provider network. The MiM header is retained when the MiM encapsulated frames are transported over the VPLS portion of the provider network. As VPLS frames exit the core network, the VPLS encapsulation fields are removed to extract the original MiM encapsulated frames for further transportation over the MiM portion of the provider network.
    Type: Application
    Filed: May 24, 2010
    Publication date: September 9, 2010
    Inventors: Dinesh Mohan, Hamid Ould Brahim
  • Patent number: 7746892
    Abstract: Frames of customer traffic may be encapsulated by adding Mac-in-Mac (MiM) encapsulation fields for transportation of the frames over a portion of provider network. The MiM encapsulated traffic may be further encapsulated using VPLS by adding VPLS encapsulation fields for transportation of the frames over another portion of the provider network. The MiM encapsulations use provider network_MAC addresses which enables VPLS MAC learning to occur using provider network MAC address space. MiM tunnels are mapped to VPLS service instances which are assigned pseudowire tags for transportation over the VPLS portion of provider network. The MiM header is retained when the MiM encapsulated frames are transported over the VPLS portion of the provider network. As VPLS frames exit the core network, the VPLS encapsulation fields are removed to extract the original MiM encapsulated frames for further transportation over the MiM portion of the provider network.
    Type: Grant
    Filed: September 30, 2006
    Date of Patent: June 29, 2010
    Assignee: Nortel Networks Limited
    Inventors: Dinesh Mohan, Hamid Ould Brahim
  • Publication number: 20090234969
    Abstract: Ethernet OAM MEPs are automatically configured in a link state protocol controlled Ethernet network. A node operating in the link state protocol controlled Ethernet network receives a Link State PDU (LSP) containing a TLV having a MEP associated with the Ethernet MAC node ID of a second node in the link state protocol controlled Ethernet network, where the path between the first and second node includes a plurality of links. The node updates a forwarding table to indicate an association between the MEP ID and a Ethernet MAC node ID of the second node. An Ethernet OAM maintenance endpoint is produced in a link state protocol controlled Ethernet network by hashing a Sys-ID to produce a MEP; storing the MEP in a TLV; and forwarding the TLV over the link state protocol controlled Ethernet network in an LSP.
    Type: Application
    Filed: October 12, 2008
    Publication date: September 17, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, Paul Unbehagen, Srikanth Keesara
  • Publication number: 20090232006
    Abstract: An OAM link trace message is sent from a source node to a target node in a link state protocol controlled Ethernet network. The link trace message using an 802.1ag format except, as a destination address, it uses either the unicast Ethernet MAC node ID of the target node, or the multicast destination address of the service instance. A method of network topology verification in a link state protocol controlled Ethernet network checks the link state protocol database at a node to ascertain the control plane topology view of at least part of the network. It then executes one or more Ethernet OAM commands from the node to ascertain the data plane topology view of the same part of the network. The control plane topology view of the network is compared to the data plane topology view of the network to see if they match. An error is flagged if they do not match.
    Type: Application
    Filed: October 12, 2008
    Publication date: September 17, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, Paul Unbehagen, Srikanth Keesara
  • Publication number: 20090232005
    Abstract: Network and performance monitoring in a link state protocol controlled Ethernet network. A first node receives a network layer monitoring command from a network layer monitoring requestor. The monitoring command is directed to a second node. The first node resolves the network layer monitoring command into one or more Ethernet OAM command(s); The first node sends the Ethernet OAM command(s) to the second node, receives the results of the Ethernet OAM command(s) from the second node; and returns the results of the Ethernet OAM command(s) in the form of a network layer response to the network layer monitoring requestor. Furthermore, network layer monitoring commands may be one or more performance monitoring commands, and the Ethernet OAM commands can include Y.1731 commands. An IP flow can be adjusted between the first node and the second node in response to the network layer response returned to the network layer monitoring requestor.
    Type: Application
    Filed: October 12, 2008
    Publication date: September 17, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, Paul Unbehagen, Srikanth Keesara
  • Patent number: 7590054
    Abstract: Protection switching in an Ethernet packet-switched network includes establishing first and second virtual circuits. The first virtual circuit carries packet traffic associated with a different service instance from packet traffic carried by the second virtual circuit. Packet traffic of the first virtual circuit is transmitted from a source network element to a sink network element through a first Ethernet tunnel. Packet traffic of the second virtual circuit is transmitted from the same source network element to the same sink network element through a second Ethernet tunnel. The second Ethernet tunnel is a different path through the Ethernet packet-switched network from the first Ethernet tunnel. During a protection switch, the first virtual circuit is switched from the first Ethernet tunnel to the second Ethernet tunnel. After the switch, packet traffic of the first virtual circuit and packet traffic of the second virtual circuit are transmitted over the second Ethernet tunnel.
    Type: Grant
    Filed: September 14, 2005
    Date of Patent: September 15, 2009
    Assignee: Nortel Networks Limited
    Inventors: Marc Holness, Dinesh Mohan, Beata Mirek
  • Publication number: 20090175176
    Abstract: The present invention relates to techniques for allowing one or more edge nodes in a backbone network to quickly and efficiently switch traffic delivery from a first virtual network to a second virtual network in response to a failure occurring in association with the first virtual network. In certain embodiments, an edge node is capable of independently detecting that a failure has occurred on the first virtual network and quickly transitioning from the first virtual network to the second virtual network for receiving or delivering traffic. Upon detecting the failure in the first virtual network, the edge node will begin delivering traffic over the second virtual network. If control messages are not already being provided over the second network, the edge node may begin providing the control messages over the second virtual network.
    Type: Application
    Filed: October 13, 2008
    Publication date: July 9, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventor: Dinesh Mohan
  • Publication number: 20090168783
    Abstract: Described are methods and communications network for carrying pseudowires over packet-switched network. A communication network includes a packet-switched network (PSN), a first provider edge (PE) device in communication with a second PE device through the PSN, and a pseudowire (PW) established between the PE devices for emulating a service across the PSN. The PW has a Virtual Circuit Connection Verification (VCCV) control channel that carries an Ethernet Operations, Administration, and Maintenance (OAM) message. In some embodiments, various data plane encapsulation formats enable a PW to emulate an Ethernet or a non-Ethernet service over an Ethernet PSN. Each encapsulation format includes an Ethernet tunnel header and a PW header that encapsulates an Ethernet or non-Ethernet payload.
    Type: Application
    Filed: February 23, 2007
    Publication date: July 2, 2009
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, Florin Balus
  • Publication number: 20090059800
    Abstract: A control protocol is run in the interconnect region between network domains so that the interconnect region may be managed using a separate control plane. According to an embodiment of the invention, a spanning tree protocol is used to establish a separate spanning tree within the interconnect region. To avoid loop formation within the interconnect region, links interconnecting adjacent edge nodes that are part of the interconnect region and which belong to a given domain are allowed to pass control frames but not data frames. OAM may be used detect link failure of a link between adjacent nodes on a given domain.
    Type: Application
    Filed: December 31, 2007
    Publication date: March 5, 2009
    Applicant: Nortel Networks Limited
    Inventor: Dinesh Mohan
  • Publication number: 20090041023
    Abstract: To allow seamless interworking between an 802.1ah service instance (ISID) and a VPLS service instance, the AGI value used to signal the setup of the pseudowire portion of the VPLS may carry the ISID value of an associated 802.1ah service instance. This allows the service instance to be identified end-to-end across the Ethernet and VPLS networks using the same value without modifying how the MPLS network operates. The VPLS network will use AGI/AII signaling to set up pseudowires on the MPLS network, but instead of using an AGI value assigned by the MPLS network, the AGI value that is assigned will be taken from the ISID value of the Ethernet frame or from ISIDs registered by the Ethernet network. The AGI message may be given a new type value indicating that the AGI message carries a value that corresponds to the ISID value on an attached Ethernet network.
    Type: Application
    Filed: April 17, 2008
    Publication date: February 12, 2009
    Applicant: Nortel Networks Limited
    Inventors: Hamid Ould Brahim, David Allan, Dinesh Mohan
  • Publication number: 20080281987
    Abstract: An existing protection mechanism is enhanced through the use of an automatic protection switching protocol data unit (APS PDU). In conjunction with transmitting Ethernet frames to a second bridge over a primary path, a first bridge transmits APS PDUs to the second bridge over a secondary path. The APS PDUs provide the second bridge with information about the protection switching mechanism being used and provide indications regarding the status of the primary path. In particular, protection switching may be facilitated by forming an APS PDU that is extended to include an indication of an identity for a trunk or a primary path before transmitting the APS PDU to the second bridge. Alternatively, after forming a regular APS PDU, protection switching may be facilitated by encapsulating the regular APS PDU with information identifying a trunk or a primary path before transmitting the APS PDU to the second bridge.
    Type: Application
    Filed: July 5, 2007
    Publication date: November 13, 2008
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Darek Skalecki, Geraldine Civil, Dinesh Mohan
  • Publication number: 20080219172
    Abstract: Described is a process and system for providing an extensible forwarding plane data communications channel adapted to selectively support operations, administration and maintenance (OAM) activity within one or more different domains of an Ethernet transport network. The data communication channel is established using Ethernet protocol data units forwarded within the forwarding plane, between network elements. The Ethernet protocol data units can be Ethernet OAM frames modified to include an OpCode indicative of a maintenance communication channel. The OAM frames are generated at a selected one of the network elements (source), forwarded along the same network path as the Ethernet frames, and terminate at another network element (destination) associated with a maintenance level identified within the OAM frame. The source and destination network elements can reside on a domain boundary using the Ethernet OAM frames flowing therebetween to relay maintenance communications channel messages.
    Type: Application
    Filed: September 12, 2006
    Publication date: September 11, 2008
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Dinesh Mohan, David Allan
  • Patent number: 7403988
    Abstract: A technique for autonomous network provisioning based on establishing a relation between network performance indices, traffic measurements and resource capacities, which provides automatic provisioning recommendations for identified critical links is disclosed. The technique may be implemented in a network through collaboration across node controllers and network controllers. A method for the autonomous provisioning of a network, wherein a plurality of nodes of the network collaborate to determine required additional resources, may comprise the steps of receiving at least one network-state measurement comprising at least one of a traffic measurement and a performance measurement; determining at least one critical link based at least in part on the at least one network-state measurement; and formulating at least one link provisioning recommendation for the at least one critical link.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: July 22, 2008
    Assignee: Nortel Networks Limited
    Inventors: Francois J. Blouin, Dinesh Mohan, Maged E. Beshai
  • Publication number: 20080172497
    Abstract: MPLS networks offering PW or VPLS services may be interconnected with Ethernet networks implemented according to 802.1ah or 802.1Qay. The MPLS network may be a core and offer services to the Ethernet access networks, or vise-versa. Additionally, a mixture of different types of access networks may be interconnected by an MPLS core or an Ethernet core. Both network interworking and service interworking are provided. OAM fault detection may be implemented via maintenance entities extending across the network or end to end depending on the combination of networks and services offered by the networks.
    Type: Application
    Filed: January 17, 2008
    Publication date: July 17, 2008
    Applicant: Nortel Networks Limited
    Inventors: Dinesh MOHAN, Gerald Smallegange, Paul Unbehagen, Nigel Bragg
  • Publication number: 20080101241
    Abstract: OAM may be implemented at an intermediate node on a PBT trunk in an Ethernet network by causing OAM frames to be addressed to the PBT trunk endpoint but causing the OAM frames to carry an indicia (Ether-type, OpCode, TLV value or combination of these and other fields) that the OAM frames are intended to be used for intermediate node OAM functions. The Ether-type, OpCode, and TLV values may be standardized values, or vendor specific values such as OpCode=51 or TLV=31 may be used. Addressing the OAM frames to the PBT trunk end point enables the OAM frames to follow the PBT trunk through the network. The OAM indicia signals to the intermediate nodes that the OAM frames are intended to be used to perform an intermediate node OAM function. The OAM frames may contain reverse trunk information to prevent the intermediate nodes from being required to store correlation between forward and reverse PBT trunks.
    Type: Application
    Filed: March 16, 2007
    Publication date: May 1, 2008
    Applicant: Nortel Networks Limited
    Inventors: Dinesh Mohan, Christopher Monti, Piotr Romanus, David Tsang, Michael Chen