Abstract: Embodiments of the present invention provide a fault detection method and system. The method includes: sending port scan packets based on at least two port pairs to a destination end, where each port pair includes a source port number and a destination port number and corresponds to a path between a source end and the destination end; receiving a response packet sent by the destination end, where the response packet carries a port pair which does not receive a port scan packet; and based on the port pair, determining a faulty path. Based on the embodiments of the present invention, port scan packets are sent based on multiple port pairs, so that the port scan packets can reach the destination end through multiple paths, so as to detect multiple paths between the source end and the destination end. The present invention can implement more efficient fault detection.

Abstract: A method for analyzing a network transmission characteristic, includes: receiving, by an intermediate network element, a service packet sent by a first service network element through the intermediate network element to a second service network element, where the service packet carries a service stream identifier, service stream information, and a control rule, where the service stream identifier is used to identify a service stream, the service stream information is used to provide a parameter that is required during transmission characteristic analysis, and the control rule is used to determine a type of the transmission characteristic analysis; and determining, by the intermediate network element, the type of the transmission characteristic analysis according to the received control rule, and performing, according to the service stream information, the transmission characteristic analysis on the service stream identified by the service stream identifier in a network application.

Abstract: Embodiments of the present invention provide a fault detection method and system. The method includes: sending port scan packets based on at least two port pairs to a destination end, where each port pair includes a source port number and a destination port number and corresponds to a path between a source end and the destination end; receiving a response packet sent by the destination end, where the response packet carries a port pair which does not receive a port scan packet; and based on the port pair, determining a faulty path. Based on the embodiments of the present invention, port scan packets are sent based on multiple port pairs, so that the port scan packets can reach the destination end through multiple paths, so as to detect multiple paths between the source end and the destination end. The present invention can implement more efficient fault detection.