A system and a method are disclosed for selectively monitoring traffic in a service provider network. The system receives a notice for a beginning of a network data flow, which responds to a request from a user device for content at an origin server. The system then determines whether to monitor the data flow from the origin server to the user device. If so determined, the system collects statistic information of the data flow and stores the statistic information to a flow record in a database. The system also maps the flow record to a subscriber of the service provider network by analyzing the statistic information of the data flow and estimates bandwidth provided to the data flow by the service provider's network based on the analysis of the statistic information of the data flow.