System and methods for network path detection
    1.
    发明授权
    System and methods for network path detection 有权
    网络路径检测的系统和方法

    公开(公告)号:US07433320B2

    公开(公告)日:2008-10-07

    申请号:US11048077

    申请日:2005-02-01

    IPC分类号: H04L12/28 H04L12/46

    摘要: Customer edge (CE) to CE device verification checks initiate routes from available CEs as a set of path verification messages, destined for remote CE routes serving a remote VPN. An extended community attribute, included among the attributes of the path verification message, stores the identity of the originating CE router. The path verification message propagates across the network, and transports the identity of the originating CE router because the originator identity is not overwritten by successive routing. Upon receipt by the remote CE, the originator is determinable from the extended community attribute. A further reachability field is also included in the extended community attribute and indicates whether per CE or per prefix is appropriate for the particular route in question. In this manner, CE-CE connectivity checks identify CEs which are reachable from other CEs. Accordingly, such a mechanism allows for route reachability aggregation on a per-CE or per-prefix reachability basis.

    摘要翻译: 客户端(CE)到CE设备验证检查从可用的CE启动路由作为一组路径验证消息,目的地是服务于远程VPN的远程CE路由。 包含在路径验证消息的属性之间的扩展团体属性存储始发CE路由器的身份。 路径验证消息通过网络传播,并传输始发CE路由器的身份,因为始发方身份不会被连续路由覆盖。 远程CE收到后,发起者可以从扩展团体属性中确定。 扩展社区属性中还包括另外的可访问性字段,并指示每个CE或每个前缀是否适合所讨论的特定路由。 以这种方式,CE-CE连接检查可以识别可从其他CE接入的CE。 因此,这种机制允许基于每个CE或每个前缀可达性的路由可达性聚合。

    System and methods for detecting network failure
    2.
    发明授权
    System and methods for detecting network failure 有权
    检测网络故障的系统和方法

    公开(公告)号:US07583593B2

    公开(公告)日:2009-09-01

    申请号:US11001149

    申请日:2004-12-01

    IPC分类号: G01R31/08 H04L12/26

    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.

    摘要翻译: 列出沿着可疑路径发送到一组节点或路由器的一系列消息的路径验证协议(PVP)识别用于在控制平面级别实现改变的转发平面问题。 消息包括请求询问另一个远程节点以获取关于接收PVP消息的节点与另外的远程节点之间的路径的信息的命令。 接收PVP消息的节点用指示响应到达远程节点的结果的命令响应来回复。 一系列消息共同地涵盖沿着始发者到接收者的路径的一组重要的路由点。 对一系列PVP消息的聚合命令响应进行分析,不仅可以识别整个路径是否可操作,还可以确定问题的位置和性质。

    Methods and apparatus based on message transmission times
    3.
    发明授权
    Methods and apparatus based on message transmission times 有权
    基于消息传输时间的方法和设备

    公开(公告)号:US07471636B2

    公开(公告)日:2008-12-30

    申请号:US11063803

    申请日:2005-02-23

    IPC分类号: H04L12/26

    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通过网络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。

    Time-based scheduling for tunnels computed by a stateful path computation element
    4.
    发明授权
    Time-based scheduling for tunnels computed by a stateful path computation element 有权
    由状态路径计算元素计算的隧道的基于时间的调度

    公开(公告)号:US09197508B2

    公开(公告)日:2015-11-24

    申请号:US13524751

    申请日:2012-06-15

    摘要: In one embodiment, a path computation element (PCE) in a computer network receives one or more path computation requests (PCReqs), and records a time of each PCReq and the corresponding requested bandwidth. Based on this information, the PCE may determine a traffic profile of the computer network, and may augment a traffic engineering database (TED) with requested bandwidth according to time based on the traffic profile. As such, prior to a particular time, the PCE may determine placement of tunnels within the traffic profile for the particular time.

    摘要翻译: 在一个实施例中,计算机网络中的路径计算元件(PCE)接收一个或多个路径计算请求(PCReq),并记录每个PCReq的时间和相应的请求带宽。 基于该信息,PCE可以确定计算机网络的流量简档,并且可以基于流量简档来根据时间来增加具有所请求带宽的流量工程数据库(TED)。 因此,在特定时间之前,PCE可以在特定时间内确定隧道在业务简档内的布置。

    Distributed stateful path computation element overlay architecture
    5.
    发明授权
    Distributed stateful path computation element overlay architecture 有权
    分布状态路径计算元素覆盖架构

    公开(公告)号:US08855014B2

    公开(公告)日:2014-10-07

    申请号:US13524071

    申请日:2012-06-15

    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。

    Inter-domain signaling to update remote path computation elements after a call set-up failure
    6.
    发明授权
    Inter-domain signaling to update remote path computation elements after a call set-up failure 有权
    呼叫建立失败后更新远程路径计算元素的域间信令

    公开(公告)号:US08817591B2

    公开(公告)日:2014-08-26

    申请号:US13524168

    申请日:2012-06-15

    IPC分类号: H04L1/00 H04L12/26

    摘要: In one embodiment, a router in a non-originating domain receives a signal to establish a tunnel, the signal having an identification (ID) of an originating path computation element (PCE) of an originating domain from where the signal to establish the tunnel originated. In response to determining that establishment of the tunnel fails, the router may signal the failure of the establishment to a local PCE of the non-originating domain, the signaling indicating the ID of the originating PCE to cause the local PCE to provide updated routing information of the non-originating domain to the originating PCE.

    摘要翻译: 在一个实施例中,非起始域中的路由器接收建立隧道的信号,该信号具有始发域的始发路径计算元件(PCE)的标识(ID),其中建立隧道的信号源自 。 响应于确定隧道的建立失败,路由器可以将建立的失败信号发送到非始发域的本地PCE,该信令指示发起PCE的ID,以使本地PCE提供更新的路由信息 的非始发域到原始PCE。

    Efficient constrained shortest path first optimization technique
    8.
    发明申请
    Efficient constrained shortest path first optimization technique 有权
    有效约束最短路径优化技术

    公开(公告)号:US20070047469A1

    公开(公告)日:2007-03-01

    申请号:US11210910

    申请日:2005-08-24

    IPC分类号: H04L12/28

    摘要: A technique performs an efficient constrained shortest path first (CSPF) optimization of Traffic Engineering (TE) Label Switched Paths (LSPs) in a computer network. The novel CSPF technique is triggered upon the detection of an event in the computer network that could create a more optimal path, such as, e.g., a new or restored network element or increased path resources. Once the novel CSPF technique is triggered, the computing node (e.g., a head-end node of the TE-LSP or a Path Computation Element, PCE) determines the set of nodes adjacent to the event, and further determines which of those adjacent nodes are within the TE-LSP (“attached nodes”). The computing node performs a CSPF computation rooted at the closest attached node to determine whether a new computed path cost is less than a current path cost (e.g., by a configurable amount), and if so, triggers optimization of the TE-LSP along the new path.

    摘要翻译: 一种技术在计算机网络中执行流量工程(TE)标签交换路径(LSP)的有效约束最短路径优先(CSPF)优化。 检测到计算机网络中可能产生更为优化的路径(例如,新的或恢复的网络元件或增加的路径资源)的事件触发了新的CSPF技术。 一旦新颖的CSPF技术被触发,计算节点(例如,TE-LSP的头端节点或路径计算元件PCE)确定与事件相邻的节点集合,并进一步确定那些相邻节点中的哪一个 在TE-LSP(“附属节点”)内。 计算节点执行根据最接近的附加节点的CSPF计算,以确定新的计算路径开销是否小于当前路径开销(例如,通过可配置的量),如果是,则触发TE-LSP沿着 新途径

    System and method for dynamically responding to event-based traffic redirection
    9.
    发明申请
    System and method for dynamically responding to event-based traffic redirection 有权
    用于动态响应基于事件的流量重定向的系统和方法

    公开(公告)号:US20060291391A1

    公开(公告)日:2006-12-28

    申请号:US11168694

    申请日:2005-06-27

    IPC分类号: H04J1/16 H04L12/28 H04L12/56

    摘要: A technique dynamically resizes Traffic Engineering (TE) Label Switched Paths (LSPs) at a head-end node of the TE-LSPs in preparation to receive redirected traffic in response to an event in a computer network. The novel dynamic TE-LSP resizing technique is based on the detection of an event in the network that could cause traffic destined for one or more other (“remote”) head-end nodes of one or more TE-LSPs to be redirected to an event-detecting (“local”) head-end node of one or more TE-LSPs. An example of such a traffic redirection event is failure of a remote head-end node or failure of any of its TE-LSPs. Specifically, the local head-end node maintains TE-LSP steady state sampling and resizing frequencies to adapt the bandwidth of its TE-LSP(s) to gradual changes in the network over time. Upon detection of an event identifying possible traffic redirection, the local head-end node enters a Fast Resize (FR) state, in which the sampling and resizing frequencies are increased to quickly adapt the TE-LSP bandwidth(s) to any received redirected traffic.

    摘要翻译: 技术动态地调整TE-LSP的头端节点处的流量工程(TE)标签交换路径(LSP),准备响应于计算机网络中的事件接收重定向的流量。 新型动态TE-LSP调整大小技术基于网络中可能导致一个或多个TE-LSP的一个或多个其他(“远程”)头端节点的流量被重定向到的事件的检测 一个或多个TE-LSP的事件检测(“本地”)头端节点。 这种流量重定向事件的示例是远程头端节点的故障或其任何TE-LSP的故障。 具体来说,本地前端节点维护TE-LSP稳态采样和调整频率,以适应其TE-LSP的带宽随时间逐渐变化的网络。 在检测到识别可能的业务重定向的事件时,本地前端节点进入快速调整大小(FR)状态,其中增加采样和调整大小频率以快速地将TE-LSP带宽适配到任何接收到的重定向业务 。

    Loop prevention technique for MPLS using service labels
    10.
    发明申请
    Loop prevention technique for MPLS using service labels 有权
    使用服务标签的MPLS环路防护技术

    公开(公告)号:US20060193248A1

    公开(公告)日:2006-08-31

    申请号:US11068081

    申请日:2005-02-28

    摘要: A local 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. The backup edge device identifies protected data packets as those which contain a predetermined “service” label in their MPLS label stacks. In other words, the service label is used as an identifier for packets that have been FRR rerouted. Upon receiving a data packet containing a service label, the backup edge device is not permitted to reroute the packet a second time, e.g., in response to another inter-domain node or link failure, thereby preventing loops from developing at the edge of the network.

    摘要翻译: 本地快速重路由(FRR)技术在计算机网络的边缘实现。 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。 备份边缘设备将受保护的数据包标识为在其MPLS标签堆栈中包含预定“服务”标签的数据包。 换句话说,服务标签被用作已被FRR重新路由的数据包的标识符。 在接收到包含服务标签的数据分组时,不允许备份边缘设备第二次重新路由该分组,例如响应于另一个域间节点或链路故障,从而防止在网络边缘发展的环路 。