Methods and apparatus for monitoring network link quality

摘要

Properties of data transmission are measured in a telecommunications network (2) comprising an access network segment (6) and a core network segment (4). A packet switched network endpoint device (10) in communication with the access network segment passively monitors data throughput between the telecommunication network and the endpoint device and conducts active tests of data transmission latency and data transmission loss by exchanging active test data packets with an active test server (8). Test result data is transmitted to the active test server in active test data packets (106, 118), avoiding additional network traffic. Active tests are conducted from the application layer. The resulting metrics accurately represent the experience of users of the endpoint devices.