A route calculation method and device

Abstract

The present invention provides a routing calculation method and device. The technical solution is: when detecting a change in the topology of the SPB-ISIS network, calculate the Cost and the number of hops of all paths from the routing device to each other routing device in the SPB-ISIS network, Determine the path with the smallest number of hops from this routing device to the path with the smallest Cost of this other routing device as the optimal path corresponding to this other routing device; The forwarding path corresponding to the other routing device under each ECT algorithm is optimized from the optimal path, and the egress port and next hop corresponding to the other routing device under the ECT algorithm are determined according to the optimized forwarding path. The invention can reduce the route calculation amount.

Description

technical field [0001] The present application relates to the technical field of communications, and in particular to a route calculation method and device. Background technique [0002] Dijkstra's algorithm is a single-source shortest path algorithm for computing minimum spanning trees in directed weighted graphs. In a directed weighted graph, each device is a node (Node), and the connection between devices is a link (Link). D(A, B) is used to represent the distance between two devices, and the distance between adjacent devices is Cost value of the interface. see figure 1 In the simple network shown, node S is connected to node D through nodes A and B respectively. Assuming that the cost of any edge in the network is 1, then S can calculate that the outgoing port to A is the port from S to A. P1, the distance is 1; the outgoing port to B is S connected to the port P2 of B, and the distance is 1; there are two equal-cost paths to D: S-A-D and S-B-D, where the outgoing por...

AI Technical Summary

Problems solved by technology

[0010] (3) When the final topology changes, only the affected routes are incrementally calculated

[0011] The use of ISPF technology can alleviate the amount of routing calculation of SPB-ISIS to a certain extent, but it is relatively simple for unicast (using itself as the root) to determine whether the network topology change affects the minimum spanning tree, and then determine whether the topology tree needs to be recalculated. But for multicast (with the multicast source as the root), it is more complicated, and it is difficult to implement the method of reducing the scope of the calculation subtree for each multicast tree, which may increase the redundant judgment process but fail to optimize the effect

In addition, for the ECT decision stipulated in the SPB-ISIS agreement, ISPF cannot play an optimized role, and if the ECT decision algorithm of the SPB-ISIS agreement itself is not optimized, the amount of calculation will deteriorate to astronomical figures

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