公开(公告)号：US20100238788A1

公开(公告)日：2010-09-23

申请号：US12383360

申请日：2009-03-23

Applicant: Sami Boutros ,  Muthurajah Sivabalan ,  David D. Ward ,  George Swallow ,  Stewart Bryant ,  Ian Michael Charles Shand

Inventor： Sami Boutros ,  Muthurajah Sivabalan ,  David D. Ward ,  George Swallow ,  Stewart Bryant ,  Ian Michael Charles Shand

IPC: G06F11/07 ,  H04L12/26

CPC classification number: H04L12/2419 ,  H04L41/06 ,  H04L43/0811 ,  H04L45/26 ,  H04L45/28 ,  H04L45/50 ,  H04L47/10

Abstract: In one embodiment, a connection verification (CV) message is initiated from an initiating maintenance end point (MEP) for an MPLS LSP, the CV message carried in a packet having a time-to-live (TTL) value of 1. Each maintenance intermediate point (MIP) along the MPLS LSP receives the packet and decrements the TTL, and in response to determining that the TTL equals 0, examines a payload of the packet to determine that the packet carries the CV message. The MIP may then append its MIP ID to a route record field of the payload having any previous MIP IDs of upstream MIPs, and forwards the CV message downstream along the MPLS LSP in a packet having a TTL value of 1. The end MEP receives the CV message, and sends a CV reply having the route record field with MIP IDs and an end MEP ID to the initiating MEP.

Abstract translation: 在一个实施例中，从针对MPLS LSP的发起维护端点（MEP）发起连接验证（CV）消息，在具有生存时间（TTL）值为1的分组中携带的CV消息。每个维护 沿着MPLS LSP的中间点（MIP）接收分组并递减TTL，并且响应于确定TTL等于0，检查分组的有效载荷以确定分组携带CV消息。 然后，MIP可以将其MIP ID附加到具有上游MIP的任何先前MIP ID的有效载荷的路由记录字段，并且在TTL值为1的分组中沿着MPLS LSP向下游转发CV消息。终端MEP接收 CV消息，并将具有MIP ID和终结MEP ID的路由记录字段的CV回复发送到初始MEP。

公开(公告)号：US07782790B1

公开(公告)日：2010-08-24

申请号：US11638063

申请日：2006-12-12

Applicant: Thomas D. Nadeau ,  George Leonard Swallow ,  Danny Prairie ,  David D. Ward

Inventor： Thomas D. Nadeau ,  George Leonard Swallow ,  Danny Prairie ,  David D. Ward

IPC: G01R31/08 ,  G06F11/00 ,  G08C15/00 ,  H04J1/16 ,  H04J3/14 ,  H04L1/00 ,  H04L12/26 ,  H04L12/28

CPC classification number: H04W40/02 ,  H04W40/12

Abstract: To reveal link bundles' component links in an MPLS network, transmit a sequence of request and reply packets. For a router receiving a request packet, the packet identifies that link bundles should be revealed, detect the link bundle links connected to the router, and for each, its component links are added to a downstream mapping field (DMF). A link bundle mapping field (LBMF) is also added to the request packet. Each LBMF specifies the component links of that link bundle by pointing to the component links added to the DMF. For a router responding to a request packet with a reply packet, determine if any links in the DMF are component links, and for each, identify a LBMF containing information regarding that link. Each component link in the DMF is processed. The component links in each LBMF are iterated through to ensure each matches the determined links in the DMF.

Abstract translation: 为了在MPLS网络中显示链路束的组件链路，发送请求和应答数据包的顺序。 对于接收到请求报文的路由器，报文会识别链路捆绑应该被显示出来，检测连接到路由器的链路捆绑链路，并且每个链路捆绑链路都被添加到下游映射域（DMF）。 链路捆绑映射字段（LBMF）也被添加到请求包中。 每个LBMF通过指向添加到DMF的组件链接来指定该链接束的组件链接。 对于响应具有应答分组的请求分组的路由器，确定DMF中的任何链路是否是组件链路，并且对于每个链路，标识包含关于该链路的信息的LBMF。 处理DMF中的每个组件链接。 迭代每个LBMF中的组件链接，以确保每个LBMF与DMF中确定的链接匹配。

公开(公告)号：US07639688B2

公开(公告)日：2009-12-29

申请号：US11183381

申请日：2005-07-18

Applicant: Clarence Filsfils ,  Stefano B. Previdi ,  John Galen Scudder ,  David D. Ward

Inventor： Clarence Filsfils ,  Stefano B. Previdi ,  John Galen Scudder ,  David D. Ward

IPC: H04L12/56

CPC classification number: H04L45/742 ,  H04L45/04 ,  H04L63/10

Abstract: A method and system for protecting valuable resources within an autonomous system network. Address prefixes within the system are designated as valuable and a flag bit is associated with the address within routing tables of routers of the network. Interfaces to border routers are identified and when packets are received at those interfaces, the packets are flagged with a flag or tag bit. The destination address of the received packet is compared to the flag bit associated with the valuable resource prefix, and if the packet is directed to that resource the packet is dropped and/or logged, but the packet is not forwarded to that resource. In specific cases an interface from an external source may be configured to not create the flag or tag bit, wherein that packet will be delivered to the destination prefix of the packet.

Abstract translation: 一种用于保护自治系统网络内有价值资源的方法和系统。 系统中的地址前缀被指定为有价值的，并且标志位与网络的路由器的路由表中的地址相关联。 识别到边界路由器的接口，并且当在这些接口处接收到分组时，分组被标记为标志或标记位。 将接收到的分组的目的地地址与与有价值的资源前缀相关联的标志位进行比较，并且如果分组指向该资源，则分组被丢弃和/或记录，但是分组不被转发到该资源。 在特定情况下，来自外部源的接口可以被配置为不创建标志或标记位，其中该分组将被传递到分组的目的地前缀。

公开(公告)号：US07583593B2

公开(公告)日：2009-09-01

申请号：US11001149

申请日：2004-12-01

Applicant: James N. Guichard ,  Jean-Philippe Vasseur ,  Thomas D. Nadeau ,  Clarence A. M. Filsfils ,  David D. Ward ,  Stefano Previdi

Inventor： James N. Guichard ,  Jean-Philippe Vasseur ,  Thomas D. Nadeau ,  Clarence A. M. Filsfils ,  David D. Ward ,  Stefano Previdi

IPC: G01R31/08 ,  H04L12/26

CPC classification number: H04L45/22 ,  H04L41/0677 ,  H04L43/50 ,  H04L45/02 ,  H04L45/28

Abstract: 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.

Abstract translation: 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。

公开(公告)号：US07499445B2

公开(公告)日：2009-03-03

申请号：US11084387

申请日：2005-03-18

Applicant: Stefano B. Previdi ,  David D. Ward ,  Jonathan C. Barth ,  John A. Harper ,  Ian Michael Charles Shand

Inventor： Stefano B. Previdi ,  David D. Ward ,  Jonathan C. Barth ,  John A. Harper ,  Ian Michael Charles Shand

IPC: H04L12/28

CPC classification number: H04L45/22 ,  H04L12/4633 ,  H04L45/00 ,  H04L45/02 ,  H04L45/026 ,  H04L2212/00

Abstract: A system and method routes data traffic over a unidirectional link of a computer network configured to implement a routing protocol, such as the ISIS routing protocol. To that end, the invention extends the ISIS routing protocol to allow dynamic discovery of neighboring routers (i.e., neighbors) that are connected via the unidirectional link and subsequent establishment of an adjacency between the neighbors over the link. Adjacency establishment is illustratively effected through the use of novel type/length/value (TLV) encoded formats appended to ISIS Hello packets to convey information between the neighbors.

Abstract translation: 系统和方法通过被配置为实现路由协议（例如ISIS路由协议）的计算机网络的单向链路路由数据业务。 为此，本发明扩展了ISIS路由协议以允许经由单向链路连接的邻近路由器（即，邻居）的动态发现，并且随后建立了链路上的邻居之间的邻接关系。 通过使用附加到ISIS Hello数据包的新型/长度/值（TLV）编码格式来说明邻居建立来传达邻居之间的信息。

公开(公告)号：US20090046723A1

公开(公告)日：2009-02-19

申请号：US11839882

申请日：2007-08-16

Applicant: Reshad A. Rahman ,  David P. Toscano ,  Sylvain Masse ,  Jonathan Parker ,  David D. Ward

Inventor： Reshad A. Rahman ,  David P. Toscano ,  Sylvain Masse ,  Jonathan Parker ,  David D. Ward

IPC: H04L12/56

CPC classification number: H04L41/0695 ,  H04L69/16

Abstract: In one embodiment, a local network device may determine an inability to establish a connectivity verification protocol (e.g., Bidirectional Forwarding Detection, “BFD”) session to a remote network device, such as from unreturned control messages. In response, the local network device may send at least one connectivity verification protocol echo message to the remote network device destined to be returned to the local network device and forwarded using a forwarding protocol. In response to receiving or not receiving the echo message, the local network device may thus determine whether the forwarding protocol is functioning between the local and remote network devices. In this manner, the local network device may determine whether an inability to establish a connectivity verification protocol session is due to an inability to forward packets between the devices, or due to the connectivity verification protocol not working (or not being configured) on the remote network device.

Abstract translation: 在一个实施例中，本地网络设备可以确定无法建立到远程网络设备的连接验证协议（例如，双向转发检测，“BFD”）会话，例如来自未返回的控制消息。 作为响应，本地网络设备可以向远程网络设备发送至少一个连接性验证协议回发消息，该远程网络设备将返回给本地网络设备并使用转发协议进行转发。 响应于接收或不接收到回波消息，本地网络设备因此可以确定转发协议是否在本地和远程网络设备之间运行。 以这种方式，本地网络设备可以确定无法建立连接性验证协议会话是由于不能在设备之间转发分组，或者由于连接验证协议在远程服务器上不工作（或未被配置）） 网络设备。

公开(公告)号：US20080123532A1

公开(公告)日：2008-05-29

申请号：US11604461

申请日：2006-11-27

Applicant: David D. Ward ,  Clarence Filsfils ,  Stefano B. Previdi ,  Jean-Philippe Vasseur

Inventor： David D. Ward ,  Clarence Filsfils ,  Stefano B. Previdi ,  Jean-Philippe Vasseur

IPC: G01R31/08

CPC classification number: H04L47/10 ,  H04L45/125 ,  H04L47/125

Abstract: In one embodiment, a node identifies a plurality of equal cost best paths to a destination, the best paths having one or more associated links. The node receives dynamic link utilization information for the associated links, and determines an amount of traffic to the destination to forward over each of the equal cost best paths, the amount being dynamically dependent upon the dynamic link utilization of the associated links for each equal cost best path.

Abstract translation: 在一个实施例中，节点识别到目的地的多个相等成本最佳路径，最佳路径具有一个或多个相关联的链路。 节点接收相关联链路的动态链路利用信息，并且确定到目的地的业务量，以在每个相等成本最佳路径上转发，该数量动态地依赖于每个相等成本的相关链路的动态链路利用率 最佳路径

公开(公告)号：US07355983B2

公开(公告)日：2008-04-08

申请号：US10775877

申请日：2004-02-10

Applicant: John Galen Scudder ,  Muthurajah Sivabalan ,  David D. Ward

Inventor： John Galen Scudder ,  Muthurajah Sivabalan ,  David D. Ward

IPC: G01R31/08

CPC classification number: H04L45/02 ,  H04L45/22

Abstract: A graceful shutdown technique modifies a routing protocol to allow an intermediate node, such as a router, to announce to its peer routers (peers) its intention to be gracefully shutdown and removed from service in a network. By announcing its intention to be removed from service, the shutdown router closes (terminates) all connections with its peers and all original routes advertised on those connections are removed (withdrawn) from service. According to the inventive technique, the shutdown router may continue forwarding packets over the network for a “grace” period of time, i.e., the router maintains the validity of those original routes so that packets mapped to the routes are not dropped (at least during the grace period). The grace period also allows backup paths to be propagated to each peer and put into service prior to a final withdrawal of the shutdown router's paths from a forwarding information base of the peer. Thus, the grace period enables the network to continue using the shutdown router as a next hop as it re-converges to use the alternate, backup paths.

Abstract translation: 优雅的关机技术修改路由协议，允许诸如路由器之类的中间节点向其对等路由器（对等体）通告其意图被正常关闭并从网络中的服务中删除。 关闭路由器通过宣布将其从服务中删除，关闭（终止）与对等体的所有连接，并将从这些连接发布的所有原始路由从服务中删除（撤销）。 根据本发明的技术，关闭路由器可以在“宽限”时间段内继续通过网络转发分组，即，路由器保持那些原始路由的有效性，使得映射到路由的分组不被丢弃（至少在 宽限期）。 宽限期还允许将备份路径传播到每个对等体，并在关闭路由器的路径从对等体的转发信息库最后提取之前投入使用。 因此，宽限期允许网络在重新收敛以使用备用路径时继续使用关闭路由器作为下一跳。

公开(公告)号：US20080049622A1

公开(公告)日：2008-02-28

申请号：US11511128

申请日：2006-08-28

Applicant: Stefano B. Previdi ,  David D. Ward ,  Jean-Philippe Vasseur ,  Ian Michael Charles Shand ,  Stewart Bryant

Inventor： Stefano B. Previdi ,  David D. Ward ,  Jean-Philippe Vasseur ,  Ian Michael Charles Shand ,  Stewart Bryant

IPC: H04L12/26

CPC classification number: H04L41/0668 ,  H04L41/5003 ,  H04L43/00 ,  H04L43/0882 ,  H04L43/16 ,  H04L45/02 ,  H04L45/12 ,  H04L45/22 ,  H04L45/28

Abstract: A technique protects against failure of a network element using Multi-Topology Repair Routing (MTRR) in a computer network. According to the novel technique, a protecting node (e.g., a router) maintains Multi-Topology Routing (MTR) databases for a first topology and at least a second topology. The protecting node determines whether any acceptable repair paths are available in the first topology for a protected network element (e.g., node, link, etc.) of the first topology. If not, the protecting node may establish a repair path (e.g., for Fast ReRoute, FRR) in the second topology for the protected network element.

Abstract translation: 一种技术可以防止网络元件在计算机网络中使用多拓扑修复路由（MTRR）的故障。 根据新颖技术，保护节点（例如，路由器）维护用于第一拓扑和至少第二拓扑的多拓扑路由（MTR）数据库。 保护节点确定第一拓扑中的受保护网络元件（例如，节点，链路等）的第一拓扑中是否有可接受的修复路径可用。 如果不是，保护节点可以在受保护网络元件的第二拓扑中建立修复路径（例如，用于Fast ReRoute，FRR）。

公开(公告)号：US08572225B2

公开(公告)日：2013-10-29

申请号：US12041378

申请日：2008-03-03

Applicant: John Galen Scudder ,  Muthurajah Sivabalan ,  David D. Ward

Inventor： John Galen Scudder ,  Muthurajah Sivabalan ,  David D. Ward

IPC: G06F15/173 ,  G06F15/16

CPC classification number: H04L45/02 ,  H04L45/22

Abstract: In one embodiment, a router generates a notification message that indicates the router is to be gracefully removed from service. The router sends the notification message to peers of the router in a network. The router then continues to forward packets for a grace period after sending the notification message, to permit backup paths to be propagated to peers, and to be put into service, prior to withdrawal from service of paths through the router. Thereafter, the router is removed from service at the expiration of the grace period.

Abstract translation: 在一个实施例中，路由器生成指示路由器被正常地从服务中移除的通知消息。 路由器向网络中的路由器的对等体发送通知消息。 然后，在发送通知消息之后，路由器继续转发宽带时段，允许将备份路径传播到对等体，并在撤销通过路由器的路径服务之前投入使用。 此后，在宽限期结束时，路由器将从服务中删除。