Technique for selecting a path computation element
    1.
    发明授权
    Technique for selecting a path computation element 有权
    选择路径计算元素的技术

    公开(公告)号:US08131873B2

    公开(公告)日:2012-03-06

    申请号:US10983280

    申请日:2004-11-05

    IPC分类号: G06F15/173

    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。

    Inter-domain optimization trigger in PCE-based environment
    2.
    发明授权
    Inter-domain optimization trigger in PCE-based environment 有权
    基于PCE的环境中的域间优化触发

    公开(公告)号:US07684351B2

    公开(公告)日:2010-03-23

    申请号:US11052280

    申请日:2005-02-07

    IPC分类号: H04L12/28

    摘要: A technique triggers optimization of a traffic engineering (TE) label switched path (LSP) that spans multiple domains of a computer network from a head-end node of a local domain to a tail-end node of a remote domain. The technique is based on the detection of an event in the remote domain (“event domain”) that could create a more optimal TE-LSP, such as, e.g., restoration of a network element or increased available bandwidth. Specifically, a path computation element (PCE) in the event domain learns of the event and notifies other PCEs of the event through an event notification. These PCEs then flood an event notification to label switched routers (LSRs) in their respective domain. Upon receiving the notification, if an LSR has one or more TE-LSPs (or pending TE-LSPs), it responds to the PCE with an optimization request for the TE-LSPs. The PCE determines whether a particular TE-LSP may benefit from optimization based on the event domain (i.e., whether the TE-LSP uses the event domain), and processes the request accordingly.

    摘要翻译: 一种技术触发跨越计算机网络的多个域从本地域的头端节点到远程域的尾端节点的流量工程(TE)标签交换路径(LSP)的优化。 该技术基于对远程域(“事件域”)中的事件的检测,其可以创建更优化的TE-LSP,例如网络元件的恢复或增加的可用带宽。 具体地,事件域中的路径计算元素(PCE)学习事件并通过事件通知通知其他PCE事件。 然后,这些PCE将事件通知泛滥到其各自域中的标签交换路由器(LSR)。 在收到通知后,如果LSR有一个或多个TE-LSP(或待处理的TE-LSP),则对该TEE的优先请求响应PCE。 PCE确定特定TE-LSP是否可以从基于事件域的优化(即,TE-LSP是否使用事件域)获益,并且相应地处理该请求。

    Inter-domain path computation technique
    4.
    发明授权
    Inter-domain path computation technique 有权
    域间路径计算技术

    公开(公告)号:US08320255B2

    公开(公告)日:2012-11-27

    申请号:US11049587

    申请日:2005-02-02

    IPC分类号: G01R31/08

    摘要: A technique computes a traffic engineering (TE) label switched path (LSP) that spans multiple domains of a computer network from a head-end node of a local domain to a tail-end node of a remote domain. The novel inter-domain TE-LSP computation technique comprises a computation algorithm executed by the head-end node, which utilizes Path Computation Elements (PCEs) located within the remote domains (i.e., other than the local domain). Specifically, the head-end node requests path segments from a PCE in each of the remote domains, in which the path segments represent paths between all entry border routers to either all exit border routers of the particular remote domain (i.e., through the domain), or to the tail-end node. Upon receiving path segments from each remote domain, the head-end node combines the path segments with local domain information, and performs a forward path computation from the head-end node to the tail-end node to find the best (i.e., “shortest”) path.

    摘要翻译: 一种技术计算跨越计算机网络的多个域的流量工程(TE)标签交换路径(LSP),从本地域的头端节点到远程域的尾端节点。 新颖的域间TE-LSP计算技术包括由前端节点执行的计算算法,其利用位于远程域内的路径计算元素(PCE)(即,除本地域之外)。 特别地,前端节点从每个远程域中的PCE请求路径段,其中路径段表示所有入口边界路由器之间到特定远程域的所有出口边界路由器(即,通过域)的路径, ,或到尾端节点。 在从每个远程域接收到路径段时,前端节点将路径段与本地域信息相结合,并且执行从前端节点到尾端节点的前向路径计算,以找到最佳(即最短) 路径。

    Reoptimization triggering by path computation elements
    5.
    发明授权
    Reoptimization triggering by path computation elements 有权
    路径计算元素的优化触发

    公开(公告)号:US07031262B2

    公开(公告)日:2006-04-18

    申请号:US10848744

    申请日:2004-05-19

    IPC分类号: H04L12/26

    摘要: A mechanism to alleviate bandwidth fragmentation in a network employing path computation element(s) to place MPLS Traffic Engineering tunnels. One application is a multiple Autonomous System or multiple area network employing distributed computation of MPLS Traffic Engineering LSPs. A particular path computation element may determine that bandwidth fragmentation is present based on monitoring of path computation failures where desired paths are blocked due to bandwidth constraints. In response to the detected bandwidth fragmentation condition, the path computation element floods a routing notification within its Autonomous System or area. Nodes respond to the routing notification by requesting reoptimization of their own previously requested Traffic Engineering LSPs allowing the path computation element an opportunity to alleviate bandwidth fragmentation.

    摘要翻译: 一种减轻使用路径计算元素的网络中带宽分段的放置MPLS流量工程隧道的机制。 一个应用是采用MPLS流量工程LSP的分布式计算的多自治系统或多区域网络。 特定路径计算元件可以基于由于带宽限制阻止期望路径的路径计算失败的监视来确定存在带宽分段。 响应于检测到的带宽分段条件,路径计算元件在其自治系统或区域内泛洪路由通知。 节点通过请求重新优化自己先前请求的流量工程LSP来响应路由通知,允许路径计算元素减轻带宽分段的机会。

    Inter-domain optimization trigger in PCE-based environment
    6.
    发明申请
    Inter-domain optimization trigger in PCE-based environment 有权
    基于PCE的环境中的域间优化触发

    公开(公告)号:US20060176820A1

    公开(公告)日:2006-08-10

    申请号:US11052280

    申请日:2005-02-07

    摘要: A technique triggers optimization of a traffic engineering (TE) label switched path (LSP) that spans multiple domains of a computer network from a head-end node of a local domain to a tail-end node of a remote domain. The technique is based on the detection of an event in the remote domain (“event domain”) that could create a more optimal TE-LSP, such as, e.g., restoration of a network element or increased available bandwidth. Specifically, a path computation element (PCE) in the event domain learns of the event and notifies other PCEs of the event through an event notification. These PCEs then flood an event notification to label switched routers (LSRs) in their respective domain. Upon receiving the notification, if an LSR has one or more TE-LSPs (or pending TE-LSPs), it responds to the PCE with an optimization request for the TE-LSPs. The PCE determines whether a particular TE-LSP may benefit from optimization based on the event domain (i.e., whether the TE-LSP uses the event domain), and processes the request accordingly.

    摘要翻译: 一种技术触发跨越计算机网络的多个域从本地域的头端节点到远程域的尾端节点的流量工程(TE)标签交换路径(LSP)的优化。 该技术基于对远程域(“事件域”)中的事件的检测,其可以创建更优化的TE-LSP,例如网络元件的恢复或增加的可用带宽。 具体地,事件域中的路径计算元素(PCE)学习事件并通过事件通知通知其他PCE事件。 然后,这些PCE将事件通知泛滥到其各自域中的标签交换路由器(LSR)。 在收到通知后,如果LSR有一个或多个TE-LSP(或待处理的TE-LSP),则对该TEE的优先请求响应PCE。 PCE确定特定TE-LSP是否可以从基于事件域的优化(即,TE-LSP是否使用事件域)获益,并且相应地处理该请求。

    Technique for selecting a path computation element
    7.
    发明申请
    Technique for selecting a path computation element 有权
    选择路径计算元素的技术

    公开(公告)号:US20060101142A1

    公开(公告)日:2006-05-11

    申请号:US10983280

    申请日:2004-11-05

    IPC分类号: G06F15/173

    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。

    Concurrent path computation using virtual shortest path tree
    8.
    发明授权
    Concurrent path computation using virtual shortest path tree 有权
    使用虚拟最短路径树的并行路径计算

    公开(公告)号:US07801048B1

    公开(公告)日:2010-09-21

    申请号:US10874660

    申请日:2004-06-23

    IPC分类号: H04L12/28 G08C15/00

    CPC分类号: H04L45/12 H04L45/04 H04L45/44

    摘要: Parallelism is exploited to accelerate the distributed computation of an MPLS Traffic Engineering LSP across multiple Autonomous Systems or areas using a virtual shortest path tree. After relaying a path computation request, a path computation element immediately begins local path segment computations even before a response to the request is received. When a response including virtual shortest path tree information is received, the tree is extended using the previously computed path segments. Also, a path computation element can verify the local feasibility of the requested path after receiving a request so that a requesting head-end or upstream path computation element can be quickly informed that a constraints-satisfying path is not available.

    摘要翻译: 利用并行化来加速跨越多个自治系统或使用虚拟最短路径树的区域的MPLS流量工程LSP的分布式计算。 在中继路径计算请求之后,即使在接收到对请求的响应之前,路径计算元素也立即开始本地路径段计算。 当接收到包括虚拟最短路径树信息的响应时,使用先前计算的路径段来扩展树。 此外,路径计算元件可以在接收到请求之后验证所请求的路径的本地可行性,使得请求的头端或上游路径计算元件可以被快速通知约束满足路径不可用。