公开(公告)号：US20020188756A1

公开(公告)日：2002-12-12

申请号：US09848743

申请日：2001-05-03

Applicant: NORTEL NETWORKS LIMITED

Inventor： Jon Weil ,  Alex Morrall ,  David Odhams ,  Kenneth Hayward ,  Loa Andersson

IPC: G06F015/173

CPC classification number: H04L41/12 ,  H04L41/0668 ,  H04L45/12 ,  H04L45/22 ,  H04L69/40

Abstract: A communications network comprises a lower transport layer and an upper overlay incorporating a plurality of routers. Adjacencies are defined between respective pairs of routers. Path protection is provided by defining a software model of the overlay of the network and defining in the model a hierarchy of protection levels for the main path. Each protection level is characterised by a respective set of one or more broken adjacencies in the model, the adjacencies to be broken being determined from a knowledge of the underlying topology. A protection level is selected and a protection path avoiding the broken adjacencies associated with that protection level is calculated. If this calculated path is not available in the real network, a lower protection level in the hierarchy is selected and the protection path calculation repeated. The process continues until a suitable protection path is identified.

Abstract translation: 通信网络包括下层传输层和结合有多个路由器的上覆盖层。 在各对路由器之间定义邻接关系。 通过定义网络覆盖的软件模型并在模型中定义主路径的保护级别的层次结构来提供路径保护。 每个保护级别的特征在于模型中的一个或多个断开的相邻集合的相应集合，根据底层拓扑的知识确定要被分解的邻接。 选择保护级别，并计算避免与该保护级别相关联的断开的邻接的保护路径。 如果这个计算的路径在实际网络中不可用，则选择层级中较低的保护级别，并重复保护路径计算。 该过程一直持续到确定合适的保护路径。