Abstract: This specification relates to portable conveyances, and in particular to a dual-function apparatus that functions as a rack in a first attachment position on the portable conveyance when the portable conveyance is in an unfolded position, and that functions as a stand in a second attachment position on the portable conveyance when the portable conveyance is in a folded position.

Abstract: This specification relates to portable conveyances, and in particular to a dual-function apparatus that functions as a rack in a first attachment position on the portable conveyance when the portable conveyance is in an unfolded position, and that functions as a stand in a second attachment position on the portable conveyance when the portable conveyance is in a folded position.

Abstract: This specification relates to portable conveyances, and in particular to a dual-function apparatus that functions as a rack in a first attachment position on the portable conveyance when the portable conveyance is in an unfolded position, and that functions as a stand in a second attachment position on the portable conveyance when the portable conveyance is in a folded position.

Abstract: In the method and device for discovering a network topology provided in embodiments of the present application, there is no need to collect multiple types of network characteristic data, which reduces consumption of network resources and can improve accuracy of discovering a network topology. The particular solution is: collecting state information of all ports of a network element of a to-be-analyzed network and deleting a port in a normally-closed state to obtain a required port set; acquiring a link set of each port in the port set and a similarity value of state information of two ports included in all links in the link set; setting a link with a maximum similarity value in the link set of each port as a candidate link of each port; and acquiring a network topology of the to-be-analyzed network according to the candidate link of each port.

Abstract: Embodiments of the present application provide a network topology discovery method and device, for performing a comprehensive analysis on results obtained after network topology discovery by using multiple types of network characteristic data, improve accuracy of network topology discovery. A specific solution comprises: collecting network characteristic data of a network element in a network; obtaining at least two corresponding link subsets respectively by using at least two types of topology discovery algorithms and according to the network characteristic data, gathering all links in the link subsets into one set to obtain a first link set, combining same links in the first link set, and for multiple links having only one same port, retaining only a link having a largest confidence value in the multiple links and deleting a remaining link, to obtain a second link set; obtaining a network topology of the network according to the second link set.

Abstract: Embodiments of the present application provide a network topology discovery method and device, for performing a comprehensive analysis on results obtained after network topology discovery by using multiple types of network characteristic data, improve accuracy of network topology discovery. A specific solution comprises: collecting network characteristic data of a network element in a network; obtaining at least two corresponding link subsets respectively by using at least two types of topology discovery algorithms and according to the network characteristic data, gathering all links in the link subsets into one set to obtain a first link set, combining same links in the first link set, and for multiple links having only one same port, retaining only a link having a largest confidence value in the multiple links and deleting a remaining link, to obtain a second link set; obtaining a network topology of the network according to the second link set.

Abstract: In the method and device for discovering a network topology provided in embodiments of the present application, there is no need to collect multiple types of network characteristic data, which reduces consumption of network resources and can improve accuracy of discovering a network topology. The particular solution is: collecting state information of all ports of a network element of a to-be-analyzed network and deleting a port in a normally-closed state to obtain a required port set; acquiring a link set of each port in the port set and a similarity value of state information of two ports included in all links in the link set; setting a link with a maximum similarity value in the link set of each port as a candidate link of each port; and acquiring a network topology of the to-be-analyzed network according to the candidate link of each port.

Abstract: An alarm root cause analyzing method includes: obtaining at least one alarm of a managed network; sending an alarm raising time to a failed link locating device; receiving an identifier of a failed link, an identifier of an affected edge device, and an identifier of a device interface of the affected edge device; querying whether any alarm from the failed link exists in the at least one alarm, if an alarm from the failed link exists, marking the alarm from the failed link as a root cause alarm; querying whether any alarm from the affected edge device exists in the at least one alarm, if an alarm from the affected edge device exists, if a service object corresponding to the alarm from the affected edge device is borne over the device interface of the affected edge device, marking the alarm from the affected edge device as a derivative alarm.

Abstract: An alarm root cause analyzing method includes: obtaining at least one alarm of a managed network; sending an alarm raising time to a failed link locating device; receiving an identifier of a failed link, an identifier of an affected edge device, and an identifier of a device interface of the affected edge device; querying whether any alarm from the failed link exists in the at least one alarm, if an alarm from the failed link exists, marking the alarm from the failed link as a root cause alarm; querying whether any alarm from the affected edge device exists in the at least one alarm, if an alarm from the affected edge device exists, if a service object corresponding to the alarm from the affected edge device is borne over the device interface of the affected edge device, marking the alarm from the affected edge device as a derivative alarm.

Abstract: A variable attenuator comprises a motor which actuates a lead screw to move rotatably, and a nut associated with the lead screw to move linearly. A neutral density filter moves along with the linearly moving nut wherein the filter is positioned between two spaced collimators for providing linear attenuation changes of light transmitted therebetween.