Patent ID: 7782798
Filing Date: 2010-08-24
Classification: H04L,H04Q

Abstract:
1. A method for identifying node reachability in an automatically switched optical network (ASON), the ASON comprising at least three control domains (CDs), each of the CDs comprising one speaker node, the ASON further comprising at least two levels, a first level network being located on a bottom level of the ASON, a second level network being located on a level above the first level network, the first level network comprising at least two of the CDs, each of the CDs of the first level network comprising nodes, the second level network comprising at least one of the CDs, each of the CDs of the second level network comprising routing controllers (RCs); and, a RC that is located within a network representing a CD of one level lower than the network, there being a one-to-one correspondence between the CD and the RC; the method comprising: disseminating, by each of nodes that are located within a first CD of the first level network, a node_id of each of the nodes in the first CD; obtaining, by a speaker node of the first CD, the node_id of each of the nodes of the first CD, forming an aggregation address of the first CD, feeding aggregation address information of the first CD to a first RC of the second level network, in accordance with a one-to-one correspondence between the first CD and the first RC, and disseminating the aggregation address information of the first CD in the first CD; disseminating, by the first RC that is located within a second CD of the second level network, the aggregation address information of the first CD in the second CD, obtaining an aggregation address of a third CD of the first level network, the third CD corresponding to a second RC that is located within the second CD, feeding aggregation address information of the third CD to the speaker node of the first CD; disseminating, by the speaker node of the first CD, the aggregation address information of the third CD in the first CD; obtaining, by each of the nodes of the first CD, aggregation address information that contains the aggregation address information of the first CD and the aggregation address information of the third CD, forming a reachable address list; and determining a source node and a destination node that are located within the first level network, searching for a RC ID and another RC ID by using a reachable address list of the source node, the RC ID corresponding to an aggregation address that contains a destination node address and belonging to a CD of the lowest level network, the another RC ID corresponding to an aggregation address that contains a source node address and belonging to the CD of the lowest level network, and determining that the source node and destination nodes are reachable to each other; wherein the speaker node disseminates the aggregation address information of the first CD in the first CD comprising: adding a top-level type-length value (TLV) that attaches the aggregation address information in No. 10 link state advertisement of a routing protocol, the top-level TLV comprising one sub-TLV for identifying attribute and parameter information and at least one sub-TLV for identifying address information; wherein the attribute and parameter information comprise network element ID, level number, a flag to show whether it is a DDRP node, RC ID of a node, area ID of a domain to which the current RC belongs, and the address information comprise storing a node_id information, address length; and disseminating the aggregation address information by using the No. 10 link state advertisement of the routing protocol.