| 摘要 |
<p>A method of determining a restoration route (or an additional route) in a fully or partially meshed communications network of nodes, in which the step of sending a route-finder signature from a node to a neighbouring node on one of a plurality of spare links of a span to the neighbouring node comprises the prior substeps of: determining whether the node has a higher or a lower ranking network node identity than that of the neighbouring node; and if it is higher ranking, sending the route-finder signature on the spare link corresponding to the lowest ranking of the node ports associated with said span; or if it is lower ranking, sending the route-finder signature on the spare link corresponding to the highest ranking of the node ports associated with said span. Any contention which occurs because the two nodes connected to a span make provisional allocation for one or more links simultaneously to different restoration routes is dealt with by a contention protocol in which the higher ranking of the two nodes knows that its provisional allocation will be confirmed, and the lower ranking of the two nodes knows that it must send a backtrack signature for the capacity that is not available.</p> |
