US Patent 10063454 Testing an upstream path of a cable network

An apparatus and method for testing an upstream path of a cable network are disclosed. The upstream path is tested by capturing and analyzing upstream data packets generated by a specific terminal device. A test instrument is connected at a node of the cable network. The test instrument establishes a communication session with the headend, informing the headend of an identifier of the device that will generate the test upstream data packet. The test upstream data packet is captured and analyzed at the headend, so that the results of the analysis can be communicated back to the test instrument. To speed up the packet capturing and filtering process, the upstream data packets can be pre-filtered based on packet duration and/or arrival time.