Methods, apparatuses and systems relating to the control and application of policies for routing data over a computer network, such as the Internet. Some implementations of the invention facilitate the configuration, deployment and/or maintenance of network routing policies. Some implementations of the invention are particularly useful for controlling the routing of data among autonomous systems or organizations. Certain implementations allow for dynamic modification of routing policy based on such factors as current Internet performance, load sharing, user-defined parameters, and time of day. In one embodiment, the present invention provides methods, apparatuses and systems implementing enhanced network path testing methodologies that enhance the efficiency of processes associated with testing of a network path, while reducing the perceived intrusiveness of test packets associated with such metrics tests.