Techniques for testing a networked system using simulated abnormal node failure are disclosed. In some embodiments, a computer system performs operations comprising: repeatedly transmitting simulated requests to a networked system on which a software application is implemented using a plurality of nodes, the networked system being configured to respond to the simulated requests using the plurality of nodes; randomly selecting one or more nodes from the plurality of nodes; terminating the randomly selected one or more nodes; restarting the terminated randomly selected one or more nodes; repeating the randomly selecting one or more nodes, the terminating the randomly selected one or more nodes, and the restarting the terminated randomly selected one or more nodes until each one of the plurality of nodes has been terminated and restarted at least once during the first period of time; and determining response times of the networked system in responding to the simulated requests.

Techniques for testing a networked system using simulated abnormal node failure are disclosed. In some embodiments, a computer system performs operations comprising: repeatedly transmitting simulated requests to a networked system on which a software application is implemented using a plurality of nodes, the networked system being configured to respond to the simulated requests using the plurality of nodes; randomly selecting one or more nodes from the plurality of nodes; terminating the randomly selected one or more nodes; restarting the terminated randomly selected one or more nodes; repeating the randomly selecting one or more nodes, the terminating the randomly selected one or more nodes, and the restarting the terminated randomly selected one or more nodes until each one of the plurality of nodes has been terminated and restarted at least once during the first period of time; and determining response times of the networked system in responding to the simulated requests.

A method of determining the presence of a loopback in one or more networks comprises storing information related to a test instance; sending a loopback detection beacon (PLD) containing information related to the test instance from a port on an originating device; monitoring the port for a predetermined time period to detect LPDBs arriving at the port during the predetermined time period; and determining whether a detected LPDB contains information corresponding to the stored information, to detect the presence of a loopback. The method may determine whether a detected loopback is a port loopback, a tunnel loopback or a service loopback. The stored information related to the test instance may be deleted if an LPDB arriving at the port and containing information corresponding to the stored information is not detected within the predetermined time period.

A device includes a transmitter coupled to a node, where the node is to couple to a wired link. The transmitter has a plurality of modes of operation including a calibration mode in which a range of communication data rates over the wired link is determined in accordance with a voltage margin corresponding to the wired link at a predetermined error rate. The range of communication data rates includes a maximum data rate, which can be a non-integer multiple of an initial data rate.

A method of determining the presence of a loopback in one or more networks comprises storing information related to a test instance; sending a loopback detection beacon (LPDB) containing information related to the test instance from a port on an originating device; monitoring the port for a predetermined time period to detect LPDBs arriving at the port during the predetermined time period; and determining whether a detected LPDB contains information corresponding to the stored information, to detect the presence of a loopback. The method may determine whether a detected loopback is a port loopback, a tunnel loopback or a service loopback. The stored information related to the test instance may be deleted if an LPDB arriving at the port and containing information corresponding to the stored information is not detected within the predetermined time period.

Systems, methods, and storage media for detecting a security intrusion of a network device are disclosed. Exemplary implementations may include a method involving, in the network device including a processor, monitor a light signal associated with a security enabled port of the network device; and in response to detecting a change in the light signal, initiate a security alert.

Disclosed are a throughput test method and apparatus. The method includes: a first network device generating a periodic detection message through a data processor; the first network device sending the detection message to a second network device to be tested, wherein a first throughput value of the first network device is greater than or equal to a second throughput value of the second network device; the first network device receiving a loopback detection message looped back by the second network device; the first network device obtaining a first quantity value of the detection messages as well as a second quantity value of the loopback detection messages; and the first network device obtaining the second throughput value characterizing the throughput of the second network device through the data processor based on the first quantity value and the second quantity value.

A network control apparatus includes a processor. The processor calculates a first OSNR corresponding to an allowable limit BER from an OSNR yield strength curve of a transmission end in a node of a transmission end. The processor acquires a reception BER of a second node of a reception end, and calculates a second OSNR corresponding to the reception BER from the OSNR yield strength curve of the transmission end. The processor calculates a first noise intensity corresponding to the allowable limit BER from the first OSNR. The processor calculates a second noise intensity corresponding to the reception BER from the second OSNR. The processor calculates a noise intensity margin, based on the first noise intensity and the second noise intensity.

A self-diagnosing validation device includes an NFC reader having an RF signal range, an active diagnostic chip positioned within the RF signal range of the NFC reader, a memory, and a processing unit. The active diagnostic chip is configured to be selectively powered during a diagnostic procedure. The processing unit is configured to determine that the diagnostic procedure needs to be performed on the NFC reader and perform the diagnostic procedure. The diagnostic procedure includes activating the active diagnostic chip by supplying power to the active diagnostic chip, reading, using the NFC reader, any data being transmitted by the active diagnostic chip, determining whether any data was read by the NFC reader, and determining whether the NFC reader is functioning properly based at least in part of the determination whether any data was read by the NFC reader

The present invention relates to a method for verifying the integrity of data transmission between a main upstream unit (10a) and a main downstream unit (20a), the method being characterised in that it includes the implementation of the following steps: a data-processing module (11a) of the main upstream unit (10a) generates a first frame (T1) including a packet (P1) of data to be transmitted and a cyclic redundancy code (E1) of said packet (P1); encapsulating the first frame (T1) in a second frame (T2) which also includes a cyclic redundancy code (C1) of the first frame (T1); encapsulating the cyclic redundancy code (E1) of the packet (P1) in a third frame (T3); the data-processing module (11b) of the at least one auxiliary upstream unit (10b) compares each of the cyclic redundancy codes (E1) extracted from the first frame (T1) with those extracted from the third frame (T3); and confirming the integrity of data transmission to the main downstream unit (20a) only if the comparison is positive.