To test the timing-recovery process of a receiving (i.e., slave) node in a packet-based network, a packet filter is configured in a test configuration that already contributes a natural delay distribution to the packet flow arriving at the slave node. The resulting delay distribution of the arriving packet flow is the combination of that natural delay distribution and the effects of the packet filter, which deterministically or statistically reduces the number of packets with delays within the anchor value window arriving at the slave node (i.e., received packets having packet delays within the slave node's anchor value window). The packet filter can be adjusted to test the slave node's timing-recovery process for a wide variety of packet-flow conditions (e.g., different rates of packets with delays within the anchor value window).