公开(公告)号：US06992978B1

公开(公告)日：2006-01-31

申请号：US09324454

申请日：1999-06-02

申请人： Pierre A. Humblet ,  Bruce D. Miller ,  Raj Shanmugaraj ,  Steven Sherry ,  Peter B. Beaulieu ,  Michael W. Fortuna ,  Michael C. Yip ,  William Abraham

发明人： Pierre A. Humblet ,  Bruce D. Miller ,  Raj Shanmugaraj ,  Steven Sherry ,  Peter B. Beaulieu ,  Michael W. Fortuna ,  Michael C. Yip ,  William Abraham

IPC分类号： H04J11/06 ,  H04J3/14

CPC分类号： H04L12/66 ,  H04L45/28

摘要： A system and method for fast and reliable failure notification and accelerated switchover for path protection in a communications network having several overlapping areas of nodes interconnected by communications links is described. Upon a failure event involving one of the communications links, a failure message is broadcast identifying the failed link, the broadcast being confined within the areas which include the failed link. A reliable transmission protocol is provided wherein at one or more of the nodes, a LAPD protocol unnumbered information frame containing the failure message is sent to connected nodes. The failure message is resent in another unnumbered information frame after a time interval unless an unnumbered acknowledgment frame containing or referencing the failure message is received from the connected node. A method of path protection includes establishing plural working paths through the nodes. For each working path, an associated protection path is precalculated. A priority is assigned to each working path and associated protection path. A protection path is precalculated for each area through which a particular working path traverses. Upon a failure event, working paths that include the failed link are switched to their respective protection paths. Higher priority protection paths can preempt lower priority paths that share at least one link. At each node, linked lists for protection path activation, working path deactivation and path preemption are implemented upon a failure event.

摘要翻译： 描述了一种用于在具有通过通信链路互连的几个重叠区域的通信网络中的用于快速可靠的故障通知和用于路径保护的加速切换的系统和方法。 在涉及通信链路中的一个的故障事件时，广播识别故障链路的故障消息，广播被限制在包括故障链路的区域内。 提供了可靠的传输协议，其中在一个或多个节点处，将包含故障消息的LAPD协议无编号信息帧发送到连接的节点。 在一段时间间隔之后，在另一个未编号的信息帧中重新发送失败消息，除非从连接的节点接收到包含或引用失败消息的未编号的确认帧。 一种路径保护方法包括：通过节点建立多个工作路径。 对于每个工作路径，预先计算相关的保护路径。 优先级被分配给每个工作路径和相关联的保护路径。 对于特定工作路径穿过的每个区域，预先计算保护路径。 在发生故障事件时，包括故障链路的工作路径切换到各自的保护路径。 较高优先级的保护路径可以抢占共享至少一个链路的较低优先级路径。 在每个节点，在故障事件时实现用于保护路径激活，工作路径禁用和路径抢占的链表。