公开(公告)号：US20050111349A1

公开(公告)日：2005-05-26

申请号：US10719003

申请日：2003-11-21

申请人： Jean Vasseur ,  Stefano Previdi ,  Clarence Filsfils ,  David Ward

发明人： Jean Vasseur ,  Stefano Previdi ,  Clarence Filsfils ,  David Ward

IPC分类号： G01S13/00 ,  H04B20060101 ,  H04B1/00 ,  H04B1/40 ,  H04B1/69 ,  H04L5/04 ,  H04L12/28 ,  H04L12/56 ,  H04M1/00 ,  H04W88/06 ,  H04W88/10 ,  H04L12/26

CPC分类号： H04L45/12 ,  H04B1/71635 ,  H04L45/02 ,  H04L45/18 ,  H04L45/22 ,  H04L45/28 ,  H04L45/46 ,  H04L45/48 ,  H04L45/50 ,  H04W88/06 ,  H04W88/10

摘要： A method and apparatus are disclosed for performing a shortest path first network routing path determination in a data communications network based in part on information about links that are associated as shared risk link groups. Micro-loops are avoided in computing shortest path first trees by considering whether links are within shared risk link groups. In a first approach, for each link state packet in a link state database, listed adjacencies are removed if the link between the node originating the LSP and the reported adjacency belongs to a shared risk link group for which one component (local link) is known as down, and a shortest path first computation is then performed. In a second approach, during the SPT computation and after having added a first node to a path, each neighboring node is added to a tentative tree if and only if, a link between the first node and the neighboring node does not belong to a shared risk link group for which one component (local link) is known as down.

摘要翻译： 公开了一种用于在数据通信网络中执行最短路径第一网络路由路径确定的方法和装置，部分地基于关于作为共享风险链路组关联的链路的信息。 通过考虑链路是否在共享风险链路组内，避免了计算最短路径树的微循环。 在第一种方法中，对于链路状态数据库中的每个链路状态分组，如果发起LSP的节点和报告的邻接关系之间的链路属于已知一个组件（本地链路）的共享风险链路组，则删除列出的邻接关系 然后执行最短路径优先计算。 在第二种方法中，在SPT计算期间，并且在将第一节点添加到路径之后，当且仅当第一节点和相邻节点之间的链路不属于共享时，每个相邻节点被添加到暂定树 一个组件（本地链路）被称为down的风险链路组。

公开(公告)号：US08488444B2

公开(公告)日：2013-07-16

申请号：US11824885

申请日：2007-07-03

申请人： Clarence Filsfils ,  Stefano Previdi ,  David Ward

发明人： Clarence Filsfils ,  Stefano Previdi ,  David Ward

IPC分类号： G01R31/08

CPC分类号： H04L45/22 ,  H04L45/02 ,  H04L45/28 ,  H04L67/14 ,  H04L69/40

摘要： A method and system for failure notification at a remote node in communication with a local node are disclosed. The local node is configured for faster failure detection than the remote node. In one embodiment, the method includes establishing a failure monitoring session between the local node and the remote node, receiving at the remote node, a failure notification from the local node, the failure notification sent using a protocol of the failure monitoring session, and rerouting traffic at the remote node in response to the failure notification.

公开(公告)号：US20060126495A1

公开(公告)日：2006-06-15

申请号：US11001149

申请日：2004-12-01

申请人： James Guichard ,  Jean-Philippe Vasseur ,  Thomas Nadeau ,  Clarence Filsfils ,  David Ward ,  Stefano Previdi

发明人： James Guichard ,  Jean-Philippe Vasseur ,  Thomas Nadeau ,  Clarence Filsfils ,  David Ward ,  Stefano Previdi

IPC分类号： H04J1/16

CPC分类号： H04L45/22 ,  H04L41/0677 ,  H04L43/50 ,  H04L45/02 ,  H04L45/28

摘要： A path verification protocol (PVP) which enumerates a series of messages sent to a set of nodes, or routers, along a suspected path identifies forwarding plane problems for effecting changes at the control plane level. The messages include a command requesting interrogation of a further remote node for obtaining information about the path between the node receiving the PVP message and the further remote node. The node receiving the PVP message replies with a command response indicative of the outcome of attempts to reach the further remote node. The series of messages collectively covers a set of important routing points along a path from the originator to the recipient. The aggregate command responses to the series of PVP messages is analyzed to identify not only whether the entire path is operational, but also the location and nature of the problem.

公开(公告)号：US20060165013A1

公开(公告)日：2006-07-27

申请号：US11045015

申请日：2005-01-26

申请人： Stefano Previdi ,  Clarence Filsfils ,  Jean-Philippe Vasseur ,  Benoit Claise ,  David Ward

发明人： Stefano Previdi ,  Clarence Filsfils ,  Jean-Philippe Vasseur ,  Benoit Claise ,  David Ward

IPC分类号： H04L12/28

CPC分类号： H04L45/02

摘要： A method of identifying an egress point to a network location in a data communications network comprising a plurality of nodes and links there between comprises the step, performed at the identifying node, of receiving a notification through the network advertising an adjacency to a network location. The method further comprises the steps, performed at the identifying node, of deriving from the notification adjacency information and identifying, from the adjacency information, the egress point.

摘要翻译： 一种识别包括在其中的多个节点和链路的数据通信网络中的网络位置的出口点的方法包括：在识别节点执行的步骤，通过网络接收通知与网络位置相邻的通知。 所述方法还包括在所述识别节点处执行的从所述通知邻接信息导出并从所述邻接信息识别所述出口点的步骤。

公开(公告)号：US20060221813A1

公开(公告)日：2006-10-05

申请号：US11098173

申请日：2005-04-04

申请人： John Scudder ,  David Ward ,  Clarence Filsfils

发明人： John Scudder ,  David Ward ,  Clarence Filsfils

IPC分类号： H04L12/56 ,  H04J1/16 ,  H04J3/14 ,  G08C15/00 ,  H04L12/28

CPC分类号： H04L45/22 ,  H04L45/02 ,  H04L45/28 ,  H04L45/50 ,  H04L47/2408

摘要： A fast reroute (FRR) technique is implemented at the edge of a computer network. In accordance with the technique, if an edge device detects a node or link failure that prevents it from communicating with a neighboring routing domain, the edge device reroutes at least some data packets addressed to that domain to a backup edge device which, in turn, forwards the packets to the neighboring domain. The rerouted packets are designated as being “protected” (i.e., rerouted) data packets before they are forwarded to the backup edge device. To that end, the edge device incorporates an identifier into the rerouted data packets to indicate that the packets are being FRR rerouted. The identifier may be a predetermined value stored at a known location in the rerouted packets'encapsulation headers, such as in their MPLS or IP headers. Upon receiving a data packet containing the identifier, the backup edge device is not permitted to reroute the packet a second time.

摘要翻译： 在计算机网络的边缘实现快速重路由（FRR）技术。 根据该技术，如果边缘设备检测到阻止其与相邻路由域通信的节点或链路故障，则边缘设备将至少一些寻址到该域的数据分组重新路由到备用边缘设备， 将数据包转发到相邻域。 重新路由的数据包在被转发到备份边缘设备之前被指定为“保护”（即重新路由）数据分组。 为此，边缘设备将重新路由的数据分组中的标识符合并，以指示分组正在被FRR重新路由。 标识符可以是存储在重新路由的分组的封装报头中的已知位置的预定值，例如在其MPLS或IP报头中。 在接收到包含标识符的数据分组时，不允许备份边缘设备再次重新路由该分组。

公开(公告)号：US08855014B2

公开(公告)日：2014-10-07

申请号：US13524071

申请日：2012-06-15

申请人： Stefano Previdi ,  Jean-Philippe Vasseur ,  Jan Medved ,  David Ward

发明人： Stefano Previdi ,  Jean-Philippe Vasseur ,  Jan Medved ,  David Ward

IPC分类号： H04L12/28 ,  H04L1/00

CPC分类号： H04L45/50 ,  H04L45/04

摘要： In one embodiment, a particular device in a computer network maintains a locally owned tunnel-state table, and joins a distributed hash table (DHT) ring. In addition, the locally owned tunnel-state table is shared with other devices of the DHT ring to establish a DHT-owned tunnel-state table. The particular device (and other devices) determines ownership of link-state advertisements (LSAs) for a specific portion of a traffic engineering database (TED) according to the DHT ring. As such, when the particular device (or any device) computes a path for a tunnel using a local TED, the particular device may request permission to use resources along the computed path that were advertised in particular LSAs from owners of those particular LSAs when not owned by the particular device.

摘要翻译： 在一个实施例中，计算机网络中的特定设备维护本地拥有的隧道状态表，并且连接分布式散列表（DHT）环。 此外，本地拥有的隧道状态表与DHT环的其他设备共享，以建立DHT拥有的隧道状态表。 特定设备（和其他设备）根据DHT环确定针对流量工程数据库（TED）的特定部分的链路状态通告（LSA）的所有权。 因此，当特定设备（或任何设备）使用本地TED计算隧道的路径时，特定设备可以请求允许沿着所计算的路径使用资源，这些资源在特定LSA的特定LSA中被发布，来自那些特定LSA的所有者 由特定设备拥有。

公开(公告)号：US20060262772A1

公开(公告)日：2006-11-23

申请号：US11135253

申请日：2005-05-23

申请人： James Guichard ,  Jean-Philippe Vasseur ,  Thomas Nadeau ,  David Ward ,  Stefano Previdi

发明人： James Guichard ,  Jean-Philippe Vasseur ,  Thomas Nadeau ,  David Ward ,  Stefano Previdi

IPC分类号： H04L12/28

CPC分类号： H04L45/308 ,  H04L43/0811 ,  H04L43/12 ,  H04L45/04 ,  H04L45/302 ,  H04L45/70 ,  H04L47/24 ,  H04L63/029

摘要： A path verification protocol (PVP) which enumerates a series of messages sent to a set of nodes, or routers, along a network path identifies connectivity and transmission characteristic attributes by defining, implementing, and analyzing path verification messages (PVMs) in a VPN environment. Typical VPN environments are characterized by service level agreements (SLAs) between service providers which specify particular service level and/or bandwidth level guarantees, typically in terms of megabits per second (MB/s) or other qualitative transfer criteria. Such guarantees are often expressed in contractual terms as Quality of Service (QoS) criteria. Configurations herein provide a mechanism for determination of paths and/or routes that satisfy a QoS or other delivery speed/bandwidth guarantee. Such a mechanism may therefore be employed to perform routing decisions for QoS based traffic. Further, such a mechanism is employable to verify QoS levels and related attributes related to contractual terms between service providers and customers.

摘要翻译： 路径验证协议（PVP），其列举沿着网络路径发送到一组节点或路由器的一系列消息，通过在VPN环境中定义，实现和分析路径验证消息（PVM）来识别连接性和传输特性属性 。 典型的VPN环境的特征在于服务提供商之间的服务级别协议（SLA），其指定特定服务级别和/或带宽级别保证，通常以兆比特每秒（MB / s）或其他定性传输标准。 这种保证通常以合同条款表示为服务质量（QoS）标准。 本文中的配置提供了用于确定满足QoS或其他传送速度/带宽保证的路径和/或路由的机制。 因此可以采用这种机制来执行基于QoS的业务的路由决策。 此外，这种机制可用于验证与服务提供商和客户之间的合同条款相关的QoS等级和相关属性。

公开(公告)号：US20060101142A1

公开(公告)日：2006-05-11

申请号：US10983280

申请日：2004-11-05

申请人： Jean-Philippe Vasseur ,  David Ward ,  Muthurajah Sivabalan ,  Stefano Previdi

发明人： Jean-Philippe Vasseur ,  David Ward ,  Muthurajah Sivabalan ,  Stefano Previdi

IPC分类号： G06F15/173

CPC分类号： H04L45/42 ,  H04L45/04 ,  H04L45/12 ,  H04L45/127 ,  H04L45/44 ,  H04L45/58

摘要： A technique efficiently selects a Path Computation Element (PCE) to compute a path between nodes of a computer network. The PCE selection technique is illustratively based on dynamic advertisements of the PCE's available path computation resources, using (i) a low-pass filter algorithm to compute such resources, and (ii) threshold determinations to control distribution of those advertisements. To that end, the novel technique enables one or more PCEs to dynamically send (advertise) their available path computation resources to a Path Computation Client (PCC) by way of the controlled advertisements. In addition, the technique enables the PCC to efficiently select a PCE (or set of PCEs) to service a path computation request based upon those available resources.

摘要翻译： 一种技术有效地选择路径计算元素（PCE）来计算计算机网络的节点之间的路径。 PCE选择技术说明性地基于PCE可用路径计算资源的动态广告，使用（i）低通滤波器算法来计算这样的资源，以及（ii）阈值确定以控制这些广告的分布。 为此，新技术使得一个或多个PCE能够通过受控广告动态地向路径计算客户端（PCC）发送（通告）它们的可用路径计算资源。 此外，该技术使得PCC能够基于这些可用资源有效地选择PCE（或一组PCE）来服务路径计算请求。

公开(公告)号：US20090144390A1

公开(公告)日：2009-06-04

申请号：US11948799

申请日：2007-11-30

申请人： Stefano Previdi ,  Robert Raszuk ,  David Ward ,  Jean-Phillippe Vasseur

发明人： Stefano Previdi ,  Robert Raszuk ,  David Ward ,  Jean-Phillippe Vasseur

IPC分类号： G06F15/16

CPC分类号： H04L45/18 ,  H04L45/04

摘要： In one embodiment, an apparatus comprises logic for optimizing network resources usage. The logic is operable to store IGP information, where the IGP information includes a set of attribute values associated with each of a set of content servers. When the logic receives a request for content from a remote peer, the logic determines one or more content servers that can provide the requested content. The logic then retrieves, from the IGP information, a plurality of attribute values associated with a non-looping path from each of the one or more content servers. For each of the one or more content servers, the retrieved attribute values include: one or more capacity values indicating capacities of one or more communication links on the non-looping path from that content server; and one or more utilization values indicating utilizations of the one or more communication links on the non-looping path from that content server. The logic then selects a content server based on the retrieved attribute values, and causes the request for the content to be sent to the selected content server.

摘要翻译： 在一个实施例中，一种装置包括用于优化网络资源使用的逻辑。 逻辑可操作地存储IGP信息，其中IGP信息包括与一组内容服务器中的每一个相关联的一组属性值。 当逻辑从远程对等体接收到对内容的请求时，逻辑确定可以提供所请求的内容的一个或多个内容服务器。 然后，逻辑从IGP信息中检索与一个或多个内容服务器中的每一个的非循环路径相关联的多个属性值。 对于所述一个或多个内容服务器中的每一个，所检索的属性值包括：指示来自该内容服务器的非循环路径上的一个或多个通信链路的容量的一个或多个容量值; 以及指示来自该内容服务器的非循环路径上的一个或多个通信链路的利用的一个或多个利用率值。 然后，该逻辑基于所检索的属性值选择一个内容服务器，并且将该内容的请求发送到所选择的内容服务器。

公开(公告)号：US20060187916A1

公开(公告)日：2006-08-24

申请号：US11063803

申请日：2005-02-23

申请人： Jean-Philippe Vasseur ,  Stefano Previdi ,  James Guichard ,  David Ward

发明人： Jean-Philippe Vasseur ,  Stefano Previdi ,  James Guichard ,  David Ward

IPC分类号： H04L12/56

CPC分类号： H04L12/56

摘要： A data communication device (e.g., a router) originates a network configuration message in response to a network topology change or so as to refresh a configuration message. The data communication device encodes a timestamp in the network configuration message. The timestamp indicates a time of originating the network configuration message. Further, the data communication device transmits the network configuration message over the network to other network devices that, in turn, initiate further broadcast of at least a portion of contents of the network configuration message. Based on the timestamp of the network configuration message, the data communication devices receiving the network configuration message identify transmission time value indicating how long the network configuration message takes to be conveyed over the network to the other network devices. The data communication devices utilize the transmission time value as a timeout period for determining whether a data communication device failure occurs.

摘要翻译： 数据通信设备（例如，路由器）响应于网络拓扑变化而发起网络配置消息，以便刷新配置消息。 数据通信设备对网络配置消息中的时间戳进行编码。 时间戳表示发起网络配置消息的时间。 此外，数据通信设备通过网络将网络配置消息发送到其他网络设备，其进一步发起网络配置消息的至少一部分内容的进一步广播。 基于网络配置消息的时间戳，接收网络配置消息的数据通信设备识别表示网络配置消息在网络上传送到其他网络设备多长时间的传输时间值。 数据通信设备利用传输时间值作为用于确定数据通信设备故障是否发生的超时周期。