公开(公告)号：US20020078232A1

公开(公告)日：2002-06-20

申请号：US09739902

申请日：2000-12-20

Applicant: Nortel Networks Limited

Inventor： Valerie A. Simpson ,  Dwight D. Jamieson ,  Nevein T. Sultan

IPC: G06F015/173

CPC classification number: H04L45/28 ,  H04L45/04 ,  H04L45/22

Abstract: A method and apparatus provides protection against resource failures in Open Shortest Path First (OSPF) networks, without increasing the complexity of the network topology and/or management. An internal router (IR) automatically maintains a back-up link in a dormant state until a network failure affecting communications with a primary adjacent area border router (ABR) is detected. Upon detection of the network failure, the IR activates the back-up link in order to enable traffic flow to an alternate adjacent ABR, which by-passes the network failure. Upon recovery of communications with the primary adjacent ABR, the IR automatically deactivates the back-up link and resumes traffic flow through the primary adjacent ABR. As a result, traffic is forwarded into the back-up link only when communications with the primary adjacent ABR has failed, thereby maintaining simplicity in the network topology, and minimizing network management and administration requirements.

Abstract translation: 一种方法和装置在开放最短路径优先（OSPF）网络中提供针对资源故障的保护，而不增加网络拓扑和/或管理的复杂性。 内部路由器（IR）自动维护备用链路处于休眠状态，直到检测到与主相邻区域边界路由器（ABR）通信的网络故障。 在检测到网络故障时，IR激活备份链路，以便能够流向交替的相邻ABR的流量，该ABR会绕过网络故障。 在恢复与主相邻ABR的通信后，IR自动停用备用链路，并恢复通过主相邻ABR的业务流。 因此，仅当与主相邻ABR的通信出现故障时才将流量转发到备用链路，从而保持网络拓扑的简单性，并最大限度地减少网络管理和管理需求。

公开(公告)号：US20030014540A1

公开(公告)日：2003-01-16

申请号：US09899265

申请日：2001-07-06

Applicant: Nortel Networks Limited

Inventor： Nevein T. Sultan ,  Dwight D. Jamieson ,  Valerie A. Simpson

IPC: G06F015/173

CPC classification number: H04L45/02 ,  H04L45/04

Abstract: A method and system enables policy-based traffic forwarding in a data network by implementing policy-based control over propagation of LSA messages through the data network. A route tag is asserted in respect of a link state advertisement (LSA) message advertising a network address. Propagation of the LSA through the data network is controlled using the asserted internal route tag. At each hop, a policy decision affecting the forwarding of the LSA is made. Exemplary policy decisions include, Pass and Discard. In addition, the forwarding table may be updated using the route and address information contained in the LSA. In this case, routes entered in the forwarding table may be tagged as an inclusion route or an exclusion route. This may be based on the value of an exclusion route flag, which can, for example, be provided as a binary null0null or null1null inserted into an unused portion of the options field of the LSA.

Abstract translation: 一种方法和系统通过对通过数据网络的LSA消息的传播实施基于策略的控制来实现数据网络中基于策略的流量转发。 关于广告网络地址的链路状态广告（LSA）消息，路由标签被断言。 通过数据网络传播LSA是通过断言的内部路由标签进行控制的。 在每一跳，做出影响LSA转发的策略决定。 示例性的政策决定包括通过和丢弃。 另外，可以使用LSA中包含的路由和地址信息来更新转发表。 在这种情况下，在转发表中输入的路由可以被标记为包含路由或排除路由。 这可以基于排除路由标志的值，其可以例如被提供为插入到LSA的选项字段的未使用部分中的二进制“0”或“1”。