公开(公告)号：US08855113B2

公开(公告)日：2014-10-07

申请号：US13611981

申请日：2012-09-12

申请人： Wenhu Lu ,  Alfred C. Lindem, III ,  Uma S. Chunduri

发明人： Wenhu Lu ,  Alfred C. Lindem, III ,  Uma S. Chunduri

IPC分类号： H04L12/28 ,  H04L12/751

CPC分类号： H04L45/02

摘要： Methods and apparatus for a network element to handle LSID collisions to prevent different LSAs associated with different routes from sharing the same LSID. According to one embodiment, responsive to determining that a tentative LSID that is generated for a first route that is being added collides with an LSID that is assigned to an LSA for a second route, and that one of the first and second routes is a host route, the host route is suppressed. If the first route is the host route, suppressing includes not originating an LSA for the first route. If the second route is the host route, suppressing includes purging the LSA for the second route and not originating an LSA for the second route. Although the host route is suppressed, network reachability of the range subsuming the host route is provided through the route that is not the host route.

摘要翻译： 用于处理LSID冲突的网元的方法和装置，以防止与不同路由相关联的不同LSA共享相同的LSID。 根据一个实施例，响应于确定为被添加的第一路由生成的临时LSID与分配给用于第二路由的LSA的LSID相冲突，并且所述第一和第二路由中的一个是主机 路由，主机路由被抑制。 如果第一条路由是主机路由，则抑制包括不发起第一条路由的LSA。 如果第二路由是主机路由，则抑制包括清除第二路由的LSA，而不是为第二路由发起LSA。 虽然主机路由被抑制，但是通过不是主机路由的路由来提供包含主机路由的范围的网络可达性。

公开(公告)号：US08681607B2

公开(公告)日：2014-03-25

申请号：US13457192

申请日：2012-04-26

申请人： Wenhu Lu ,  Sriganesh Kini

发明人： Wenhu Lu ,  Sriganesh Kini

IPC分类号： G01R31/08

CPC分类号： H04L45/42 ,  H04L45/00 ,  H04L45/02 ,  H04L45/123 ,  H04L45/1283 ,  H04L45/28 ,  H04L45/50

摘要： A network element implementing Multiprotocol Label Switching to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP. The network element receives a request for a generation of an LSP, determines that the request for the generation of the LSP is for the back-up LSP, locates each link of the primary LSP in a traffic engineering database, modifies each link of the primary LSP to have a link cost significantly greater than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP, executes a Constrained Shortest Path First algorithm to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP, and returns the back-up LSP.

摘要翻译： 实现多协议标签交换的网元，自动创建一个最佳的确定性备份标签交换路径（LSP），最大限度地脱离主LSP，以提供可靠的备份到主LSP。 网元接收到生成LSP的请求，确定生成LSP的请求是用于备份LSP，将主LSP的每个链路定位在流量工程数据库中，修改主链路的每个链路 LSP具有明显大于实际链路成本的链路成本，以阻止在备用LSP中使用主LSP的每个链路，执行约束最短路径优先算法以获得备份LSP，其中备份LSP 由于主LSP的每个链路的修改成本，LSP与主LSP的最大不相容性，并返回备用LSP。

公开(公告)号：US08289961B2

公开(公告)日：2012-10-16

申请号：US12544789

申请日：2009-08-20

申请人： Wenhu Lu ,  Alfred C. Lindem, III ,  Uma S. Chunduri

发明人： Wenhu Lu ,  Alfred C. Lindem, III ,  Uma S. Chunduri

IPC分类号： H04L12/28

CPC分类号： H04L45/02

摘要： Methods and apparatus for a network element to handle LSID collisions to prevent different LSAs associated with different routes from sharing the same LSID. According to one embodiment, responsive to determining that a tentative LSID that is generated for a first route that is being added collides with an LSID that is assigned to an LSA for a second route, and that one of the first and second routes is a host route, the host route is suppressed. If the first route is the host route, suppressing includes not originating an LSA for the first route. If the second route is the host route, suppressing includes purging the LSA for the second route and not originating an LSA for the second route. Although the host route is suppressed, network reachability of the range subsuming the host route is provided through the route that is not the host route.

摘要翻译： 用于处理LSID冲突的网元的方法和装置，以防止与不同路由相关联的不同LSA共享相同的LSID。 根据一个实施例，响应于确定为被添加的第一路由生成的临时LSID与分配给用于第二路由的LSA的LSID相冲突，并且所述第一和第二路由中的一个是主机 路由，主机路由被抑制。 如果第一条路由是主机路由，则抑制包括不发起第一条路由的LSA。 如果第二路由是主机路由，则抑制包括清除第二路由的LSA，而不是为第二路由发起LSA。 虽然主机路由被抑制，但是通过不是主机路由的路由来提供包含主机路由的范围的网络可达性。

公开(公告)号：US08233387B2

公开(公告)日：2012-07-31

申请号：US12614323

申请日：2009-11-06

申请人： Wenhu Lu ,  Sriganesh Kini

发明人： Wenhu Lu ,  Sriganesh Kini

IPC分类号： G01R31/08

CPC分类号： H04L45/42 ,  H04L45/00 ,  H04L45/02 ,  H04L45/123 ,  H04L45/1283 ,  H04L45/28 ,  H04L45/50

摘要： A network element implementing Multiprotocol Label Switching to automatically create an optimal deterministic back-up Label Switch Path (LSP) that is maximally disjointed from a primary LSP to provide a reliable back up to the primary LSP. The network element receives a request for a generation of an LSP, determines that the request for the generation of the LSP is for the back-up LSP, locates each link of the primary LSP in a traffic engineering database, modifies each link of the primary LSP to have a link cost significantly greater than an actual link cost to discourage use of each link of the primary LSP in the back-up LSP, executes a Constrained Shortest Path First algorithm to obtain the back-up LSP, wherein the back-up LSP has a maximum disjointedness from the primary LSP due to a modified cost of each link of the primary LSP, and returns the back-up LSP.

摘要翻译： 实现多协议标签交换的网元，自动创建一个最佳的确定性备份标签交换路径（LSP），最大限度地脱离主LSP，以提供可靠的备份到主LSP。 网元接收到生成LSP的请求，确定生成LSP的请求是用于备份LSP，将主LSP的每个链路定位在流量工程数据库中，修改主链路的每个链路 LSP具有明显大于实际链路成本的链路成本，以阻止在备用LSP中使用主LSP的每个链路，执行约束最短路径优先算法以获得备份LSP，其中备份LSP 由于主LSP的每个链路的修改成本，LSP与主LSP的最大不相容性，并返回备用LSP。

公开(公告)号：US20120075986A1

公开(公告)日：2012-03-29

申请号：US12983126

申请日：2010-12-31

申请人： Wenhu Lu ,  Albert Jining Tian ,  Sriganesh Kini

发明人： Wenhu Lu ,  Albert Jining Tian ,  Sriganesh Kini

IPC分类号： H04L12/26

CPC分类号： H04L45/22 ,  H04L45/02 ,  H04L45/28 ,  H04L45/50 ,  H04L45/66

摘要： Fast flooding based fast convergence to recover from a network failure. A router detects a network failure, and responsive to that failure, transmits a fast failure notification message to a set of one or more routers. The fast failure notification message includes information that identifies the network failure and also indicates that the fast failure notification message is to be flooded by the set of routers independently of convergence. The router updates a routing table to reflect the network failure. The transmission of the fast failure notification message is performed prior to completion of the routing table update to reflect the network failure.

摘要翻译： 快速洪泛快速收敛，从网络故障中恢复。 路由器检测到网络故障，并响应于该故障，将快速故障通知消息发送到一个或多个路由器的集合。 快速故障通知消息包括识别网络故障的信息，并且还指示快速故障通知消息将被该组路由器独占于收敛而泛洪。 路由器更新路由表以反映网络故障。 在完成路由表更新之前执行快速故障通知消息的传输以反映网络故障。

公开(公告)号：US20110044348A1

公开(公告)日：2011-02-24

申请号：US12546433

申请日：2009-08-24

申请人： Sriganesh Kini ,  Wenhu Lu

发明人： Sriganesh Kini ,  Wenhu Lu

IPC分类号： H04L12/56

CPC分类号： H04L45/16 ,  H04L45/02 ,  H04L45/021 ,  H04L45/507 ,  H04L2463/143

摘要： A method and apparatus for LDP-IGP synchronization for broadcast networks. In one embodiment of the invention, responsive to a network element bringing up an adjacency with a Designated Router of the broadcast network on a broadcast interface, that network element advertises in its Link State Advertisement (LSA) a peer-to-peer (P2P) adjacency to each member of the broadcast network that has bidirectional IGP communication with the network element instead of advertising a pseudo-node adjacency to the pseudo-node of the broadcast network. Each P2P adjacency includes a high cost to discourage use of those links for transit traffic. After LDP becomes operational with all neighbors on the broadcast interface, the network element advertises the pseudo-node adjacency instead of the P2P adjacencies. Accordingly, transit traffic is avoided through that network element until LDP is operational with all neighbors on the broadcast interface.

摘要翻译： 用于广播网络的LDP-IGP同步的方法和装置。 在本发明的一个实施例中，响应于在广播接口上与广播网络的指定路由器相邻的网络元件，该网络单元在其链路状态通告（LSA）中通告对等（P2P） 与广播网络的与网络单元进行双向IGP通信的每个成员相邻，而不是向广播网络的伪节点广告伪节点邻接。 每个P2P邻接包括高昂的成本，以阻止使用这些链路进行过境业务。 LDP与广播接口上的所有邻居操作后，网元发布伪节点邻接而不是P2P邻接。 因此，通过该网络元件避免转接流量，直到LDP与广播接口上的所有邻居一起运行。

公开(公告)号：US20090285101A1

公开(公告)日：2009-11-19

申请号：US12121601

申请日：2008-05-15

申请人： Wenhu Lu

发明人： Wenhu Lu

IPC分类号： H04L12/26

CPC分类号： H04L41/12 ,  H04L45/12 ,  H04L45/122 ,  H04L45/125 ,  H04L45/20 ,  H04L45/42 ,  H04L45/50

摘要： A method and apparatus for performing a dynamically runtime adjustable constrained shortest path first (CSPF) computation of a label switched path (LSP) is described. In one embodiment of the invention, a network element acting as a source of the LSP receives a request to compute the LSP which includes one or more traffic engineering constraints. If the request includes at least one additive constraint, the network element performs a CSPF calculation. If the request does not include an additive constraint, the network element prunes each link that does not satisfy each of the constraints, and prunes those links whose paths converge at an intermediary network element according to cost, calculates a path to the destination according to cost. Other methods and apparatuses are also described.

摘要翻译： 描述了用于执行标签交换路径（LSP）的动态运行时可调约束最短路径优先（CSPF）计算的方法和装置。 在本发明的一个实施例中，充当LSP的源的网络元件接收包括一个或多个业务工程约束的计算LSP的请求。 如果请求包括至少一个附加约束，则网元执行CSPF计算。 如果请求不包含加性约束，则网络元素修剪不满足每个约束的每个链路，并根据成本修剪路由在中间网元收敛的链路，根据成本计算到目的地的路径 。 还描述了其它方法和装置。

公开(公告)号：US08964758B2

公开(公告)日：2015-02-24

申请号：US13349392

申请日：2012-01-12

申请人： Wenhu Lu ,  Ing-Wher Chen ,  Alfred C. Lindem, III

发明人： Wenhu Lu ,  Ing-Wher Chen ,  Alfred C. Lindem, III

IPC分类号： H04L12/28 ,  H04L12/56 ,  H04J1/16 ,  H04J3/14 ,  H04L12/703 ,  H04L12/775 ,  H04L12/773 ,  H04L12/707

CPC分类号： H04L45/28 ,  H04L45/22 ,  H04L45/58 ,  H04L45/60

摘要： A network element is configured to reduce the synchronization costs for implementing Open Shortest Path First (OSPF) Nonstop routing (NSR). The reduced synchronization costs are achieved by reducing the number of acknowledgement messages that are needed to be sent though reliable inter-process communication (IPC) between the active OSPF instance and the standby OSPF instance. The number of acknowledgement messages is reduced by tracking the link state advertisements (LSAs) that have been sent by the active OSPF instance to the standby OSPF instance and by the standby OSPF replying with an acknowledgement of only the last LSA in a group of LSAs received from the active OSPF instance, where the group can have a variety of boundaries such as a group of LSAs in an IPC message. This avoids having a significant number of acknowledgement messages sent through the IPC.

摘要翻译： 网元被配置为减少实现开放最短路径优先（OSPF）不间断路由（NSR）的同步成本。 降低的同步成本是通过减少在活动的OSPF实例和备用OSPF实例之间通过可靠的进程间通信（IPC）需要发送的确认消息的数量来实现的。 通过跟踪已经由主动OSPF实例发送到备用OSPF实例的链路状态通告（LSA），以及通过仅接收所接收到的一组LSA中最后一个LSA的确认的备用OSPF来回复确认消息的数量 来自活动的OSPF实例，其中组可以具有各种边界，例如IPC消息中的一组LSA。 这避免了通过IPC发送大量确认消息。

公开(公告)号：US08958430B2

公开(公告)日：2015-02-17

申请号：US13349530

申请日：2012-01-12

申请人： Ing-Wher Chen ,  Wenhu Lu ,  Alfred C. Lindem, III

发明人： Ing-Wher Chen ,  Wenhu Lu ,  Alfred C. Lindem, III

IPC分类号： H04L12/28 ,  H04L12/56 ,  H04L12/721 ,  H04L12/703

CPC分类号： H04L45/12 ,  H04L45/023 ,  H04L45/123 ,  H04L45/22 ,  H04L45/28 ,  H04L45/58 ,  H04L45/60

摘要： Open Shortest Path First (OSPF) Non-stop Routing (NSR) with frozen standby LSDB is described. A network element includes a first OSPF instance initially acting as an active OSPF instance and a second OSPF instance initially acting as a standby OSPF instance. The second OSPF instance receives LSAs from the first OSPF instance and installs the LSAs in its LSDB. The LSAs in the LSDB are only aged by the active OSPF instance. If and when the second OSPF instance becomes the active OSPF instance, the second OSPF instance then ages the LSAs in the LSDB and processes each of the LSAs according to the aging of that LSA, where processing includes one of purging that LSA and refreshing that LSA.

摘要翻译： 描述了具有冻结备用LSDB的开放最短路径优先（OSPF）不间断路由（NSR）。 一个网络元素包括最初起作用的活动的OSPF实例的第一个OSPF实例和最初充当备用OSPF实例的第二个OSPF实例。 第二个OSPF实例从第一个OSPF实例接收LSA，并在其LSDB中安装LSA。 LSDB中的LSA只能由活动的OSPF实例进行老化。 如果当第二个OSPF实例成为活动的OSPF实例时，第二个OSPF实例会老化LSDB中的LSA，并根据该LSA的老化处理每个LSA，其中处理包括清除LSA并刷新该LSA 。

公开(公告)号：US20140348002A1

公开(公告)日：2014-11-27

申请号：US14455842

申请日：2014-08-08

申请人： Wenhu LU ,  Sriganesh KINI ,  Srikanth NARAYANAN

发明人： Wenhu LU ,  Sriganesh KINI ,  Srikanth NARAYANAN

IPC分类号： H04L12/723 ,  H04L12/733

CPC分类号： H04L45/50 ,  H01L45/04 ,  H04L45/04 ,  H04L45/20 ,  H04L45/42

摘要： A method in a router for participating in computation of a constraint-based label switched path (LSP) that spans a plurality of areas to reach a destination is described. The method comprises computing a path segment that meets a set of one or more constraints to at least one border router of the first area, transmitting a path computation request message to a path computation element in a second one of the plurality of areas, receiving a path computation reply message from the path computation element, and stitching at least one of the set of computed path segments that are specified in the path computation reply message with the path segment computed by the router to form at least part of the constraint-based LSP.

摘要翻译： 描述了一种用于参与跨越到达目的地的多个区域的基于约束的标签交换路径（LSP）的计算的路由器中的方法。 该方法包括：计算满足一个或多个约束的集合的路径段，以将所述第一区域的至少一个边界路由器的路径计算请求消息发送到所述多个区域中的第二区域中的路径计算单元， 路径计算应答消息，并且将路径计算应答消息中指定的所计算的路径段中的至少一个与由路由器计算的路径段进行拼接，以形成至少部分基于约束的LSP 。