1. A method for testing line state comprising: monitoring traffic through a communications path; controlling generating of a test vector with a reflector predictor function, the reflector/predictor function having a first mode that has a vector control input fed by live traffic statistical values to resemble live packet flows monitored though the communications path and a second mode that includes a set of preset vectors that are triggered automatically to predict performance, wherein attributes of the test vector simulate configurations of the monitored traffic and include at least frame size; initiating communication of the test vector to one or more end devices; dynamically reconfiguring the attributes of the test vector during the communication of the test vector to simulate real-time changes in the monitored traffic in response to detecting the real-time changes in the monitored traffic; measuring resulting test vector performance information for each of the attributes of the test vector; and generating a dynamically updatable performance map utilizing the attributes of the test vector and the performance information, wherein the performance map is a multi-dimensional array of test results based at least in part on the attributes of the test vector and the performance information of the test vector, and wherein the performance map is queried by an application before initiating a process or communication, wherein the application selects a class of service marking for the process or communication in real time based on the performance information within the class of service reported hi the performance map.