In distributed system the knowledge of the network is mandatory to know the available connexion and from the performance point of view. Indeed, to be able to efficiently schedule network transfers on computing platforms such as clusters, grids or clouds, accurate and timely predictions of network transfers completion times are needed. We designed a new metrology and performance prediction framework called Pilgrim which offers a service predicting the completion times of current and concurrent TCP transfers. This service uses SimGrid to simulate the network transfers, and we will show some experimental results comparing the predictions obtained from Pilgrim to the real transfer completion times.