A probing router is used at a source site of a virtual private network. In-band probing operations are performed by components within the probing router, using processing resources available from a router engine portion of the probing router. In this way, changes in the network and service level agreement statistic collection processes may be quickly and easily accommodated within the probing router. Furthermore, the probing router communicates the probe message through an in-band communication channel so as to provide a direct measurement of service level data for the channel used for communicating information between the source site and a destination site.