US 12,132,639 B2
Method for optimal routing in an inter-area SRMPLS IGP network, nodes and system thereof
Mahendra Singh Negi, Bengaluru (IN); Sreekanth Sreenivasan, Bengaluru (IN); and Mobashshera Rasool, Bengaluru (IN)
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed by Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed on Sep. 20, 2021, as Appl. No. 17/479,129.
Application 17/479,129 is a continuation of application No. PCT/CN2020/080308, filed on Mar. 20, 2020.
Claims priority of application No. 201931010956 (IN), filed on Mar. 20, 2019.
Prior Publication US 2022/0006721 A1, Jan. 6, 2022
Int. Cl. H04L 45/02 (2022.01); H04L 45/12 (2022.01); H04L 45/121 (2022.01); H04L 45/50 (2022.01)
CPC H04L 45/04 (2013.01) [H04L 45/123 (2013.01); H04L 45/121 (2013.01); H04L 45/50 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
advertising, based on an extended inter-area interior gateway protocol (IGP), by each area border node of at least two area border nodes to a source node of a second set of nodes, a Flexible Algorithm (Flex-Algo) metric of the respective area border node that is associated with a path to a destination node of a first set of nodes, to advertise at least two Flex-Algo metrics to the source node, wherein an IGP network comprises a first area and a second area, the first area includes the first set of nodes and the at least two area border nodes, and the second area includes the second set of nodes and the at least two area border nodes;
calculating, by the source node for each of the at least two Flex-Algo metrics received by the source node, a respective inter-area path metric associated with a corresponding path that passes through a corresponding area border node to reach the destination node, to calculate at least two inter-area path metrics, wherein each respective inter-area path metric is based on the respective Flex-Algo metric advertised by the corresponding area border node;
determining, by the source node based on each of the at least two calculated inter-area path metrics, an optimal path that includes one area border node of the at least two area border nodes and that reaches the destination node; and
forwarding a packet from the source node to the destination node using the determined optimal path.