公开(公告)号：US20210337493A1

公开(公告)日：2021-10-28

申请号：US17369770

申请日：2021-07-07

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  PATRICK WETTERWALD ,  JEAN-PHILIPPE VASSEUR ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04W56/00 ,  G06F16/901

Abstract: In one embodiment, a method comprises: receiving, by a constrained wireless network device comprising a local clock, a plurality of messages from respective neighboring wireless network devices advertising as available parent devices in a directed acyclic graph of a time-synchronized network that is synchronized to a master clock device; determining, by the constrained wireless network device, a corresponding timing error of the local clock relative to each message output by the corresponding available parent device; and executing, by the constrained wireless network device, a distributed time synchronization of the local clock with the master clock device based on correlating the respective timing errors relative to the local clock.

公开(公告)号：US20210288803A1

公开(公告)日：2021-09-16

申请号：US17336179

申请日：2021-06-01

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  HUIMIN SHE ,  PATRICK WETTERWALD ,  AKRAM ISMAIL SHERIFF ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04L9/32 ,  H04L29/12 ,  H04L9/30 ,  G06F16/901

Abstract: In one embodiment, a method comprises: receiving, by a parent network device providing at least a portion of a directed acyclic graph (DAG) according to a prescribed routing protocol in a low power and lossy network, a destination advertisement object (DAO) message, the DAO message specifying a target Internet Protocol (IP) address claimed by an advertising network device in the DAG and the DAO message further specifying a secure token associated with the target IP address; and selectively issuing a cryptographic challenge to the DAO message to validate whether the advertising network device generated the secure token.

公开(公告)号：US20210022098A1

公开(公告)日：2021-01-21

申请号：US16511321

申请日：2019-07-15

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  PATRICK WETTERWALD ,  JEAN-PHILIPPE VASSEUR ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04W56/00 ,  G06F16/901

Abstract: In one embodiment, a method comprises: receiving, by a constrained wireless network device comprising a local clock, a plurality of messages from respective neighboring wireless network devices advertising as available parent devices in a directed acyclic graph of a time-synchronized network that is synchronized to a master clock device; determining, by the constrained wireless network device, a corresponding timing error of the local clock relative to each message output by the corresponding available parent device; and executing, by the constrained wireless network device, a distributed time synchronization of the local clock with the master clock device based on correlating the respective timing errors relative to the local clock.

公开(公告)号：US20200322838A1

公开(公告)日：2020-10-08

申请号：US16372744

申请日：2019-04-02

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  PATRICK WETTERWALD ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04W28/02 ,  H04L12/931

Abstract: In one embodiment, a method comprises: determining, by a network switching device, whether the network switching device is configured as one of multiple leaf network switching devices, one of multiple Top-of-Fabric (ToF) switching devices, or one of multiple intermediate switching devices in a switched data network having a leaf-spine switching architecture; if configured as a leaf switching device, limiting flooding of an advertisement only to a subset of the intermediate switching devices in response to detecting a mobile destination is reachable; if configured as an intermediate switching device, flooding the advertisement, received from any one of the leaf network switching devices, to connected ToF switching devices without installing any routing information specified within the advertisement; if configured as a ToF switching device, installing from the flooded advertisement the routing information and tunneling a data packet, destined for the mobile destination, to the leaf switching device having transmitted the advertisement.

公开(公告)号：US20200259678A1

公开(公告)日：2020-08-13

申请号：US16585839

申请日：2019-09-27

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  RAMAKRISHNAN CHOKKANATHAPURAM SUNDARAM ,  PATRICK WETTERWALD ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04L12/44 ,  H04L12/18 ,  H04L29/06 ,  H04L12/46

Abstract: In one embodiment, a method comprises identifying within a network topology, by an apparatus, a plurality of network devices; and establishing by the apparatus, a multiple tree topology comprising a first multicast tree and a second multicast tree, the first and second multicast trees operable as redundant trees for multicast traffic in the network topology, the establishing including: allocating a first of the network devices as a corresponding root of the first multicast tree, allocating a first group of intermediate devices from the network devices as first forwarding devices in the first multicast tree, allocating a second group of intermediate devices as belonging to first leaf devices in the first multicast tree, and allocating terminal devices of the network devices as belonging to the first leaf devices, and allocating a second of the network devices as the corresponding root of the second multicast tree, allocating the second group of intermediate devices as second forwarding devices in the second multicast tree, allocating the first group of intermediate devices as belonging to second leaf devices in the second multicast tree, and allocating the terminal devices as belonging to the second leaf devices.

公开(公告)号：US20200186362A1

公开(公告)日：2020-06-11

申请号：US16685058

申请日：2019-11-15

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  HUIMIN SHE ,  PATRICK WETTERWALD ,  AKRAM ISMAIL SHERIFF ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04L9/32 ,  H04L12/725

Abstract: In one embodiment, a method comprises: identifying, by a root network device of a directed acyclic graph (DAG) in a low power and lossy network, a child network device in the DAG, including identifying a first rank associated with the child network device; allocating, by the root network device, an allocated rank for the child network device, the allocated rank different from the first rank; and outputting, by the root network device, a message to the child network device specifying the allocated rank, the message causing the child network device to implement the allocated rank in the DAG, including causing the child network device to generate and output a Destination Oriented Directed Acyclic Graph (DODAG) information object (DIO) message specifying the child network device is using the allocated rank.

公开(公告)号：US20200053006A1

公开(公告)日：2020-02-13

申请号：US16657179

申请日：2019-10-18

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  PATRICK WETTERWALD

IPC: H04L12/753 ,  H04L12/751 ,  H04L12/705 ,  H04L12/24

Abstract: In one embodiment, a network device (e.g., a RPL router) executes fast local RPL recovery in a low power and lossy network (LLN). The network device, in response to becoming an orphan in a directed acyclic graph (DAG) topology, can utilize the data plane to maintain at least some data traffic by randomly forwarding the data traffic to identified neighbor devices, while eliminating children from the list of forwarders and by finding successors that can be used for re-parenting. Hence, when a RPL network device having lost its last feasible parent can avoid data loss and accelerate a re-parenting process using local repair in the data plane instead of the control plane of the routing protocol used to establish the DAG topology.

公开(公告)号：US20190081892A1

公开(公告)日：2019-03-14

申请号：US15922177

申请日：2018-03-15

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  PATRICK WETTERWALD

IPC: H04L12/753 ,  H04L12/751 ,  H04L12/24 ,  H04L12/705

Abstract: In one embodiment, a network device (e.g., a RPL router) executes fast local RPL recovery in a low power and lossy network (LLN). The network device, in response to becoming an orphan in a directed acyclic graph (DAG) topology, can utilize the data plane to maintain at least some data traffic by randomly forwarding the data traffic to identified neighbor devices, while eliminating children from the list of forwarders and by finding successors that can be used for re-parenting. Hence, when a RPL network device having lost its last feasible parent can avoid data loss and accelerate a re-parenting process using local repair in the data plane instead of the control plane of the routing protocol used to establish the DAG topology.

公开(公告)号：US20180063073A1

公开(公告)日：2018-03-01

申请号：US15800274

申请日：2017-11-01

Applicant: Cisco Technology, Inc.

Inventor： PATRICK WETTERWALD ,  ERIC MICHEL LEVY-ABEGNOLI ,  PASCAL THUBERT

IPC: H04L29/12

CPC classification number: H04L61/103 ,  H04L61/6022

Abstract: In one embodiment, a method comprises detecting, by a network device, an endpoint device attempting to access a data network via a data link; and generating, by the network device, a unique device signature for identifying the endpoint device based on the network device identifying a sequence of link layer data packets transmitted by the endpoint device upon connection to the data link, the unique device signature identifying a behavior of the endpoint device independent of any link layer address used by the endpoint device.

公开(公告)号：US20170251468A1

公开(公告)日：2017-08-31

申请号：US15055690

申请日：2016-02-29

Applicant: Cisco Technology, Inc.

Inventor： PASCAL THUBERT ,  PATRICK WETTERWALD ,  JEAN-PHILIPPE VASSEUR ,  ERIC MICHEL LEVY-ABEGNOLI

IPC: H04W72/04

CPC classification number: H04W72/0446 ,  H04W84/005 ,  H04W84/22

Abstract: In one embodiment, a method comprises determining a movable network device is moving along a repeatable sequence of access point devices in a deterministic network; and establishing a deterministic track along the repeatable sequence of access point devices, the deterministic track comprising insertion slots allocated for insertion of a data packet, by the movable network device, into the deterministic track via any one of the respective access point devices.