Abstract
Provided is a computer-implemented method to extract a subgraph from a graph which is stored with a storage device without prior knowledge of the structure of the graph. The graph represents a network. The subgraph starts from at least one selected node into a selected direction. Each directed edge of the graph is composed of an outgoing edge which is connected to a start node and an incoming edge which is connected to an end node. The subgraph is extracted according to a traversal of the graph starting from the at least one selected node into the selected direction according to a predefined graph traversal protocol.