TEST UNIT FOR USE AT A NETWORK INTERFACE DEVICE

摘要

A test unit provides testing capability at a network interface device (NID). The test unit may be remotely activated so that testing is initiated upon activation from a remote site. In one embodiment, a characteristic signal is sent over a telephone line toward the NID. A characteristic signal is detect ed and the testing unit is activated. The testing unit may perform multiple typ es of tests, including tests for detecting line loss, line noise and latency. T he test unit may be implemented using electronic circuitry or using an intelligent computer system.