 and B, ePRTC-A and ePRTC-B). This is a quick test that will validate that the recovery of phase in the receiver is aligned with the input sig- nal. This confirms that the receiver will accurately source phase from a GPS signal. Phase Wander and Jitter: Dynamic TE G.8272 and G.8272.1 specify maximum time interval error (MTIE) and time deviation (TDEV) masks for wander generation, which, for MTIE, reaches the ceiling of 100 ns for PRTC-A, 40 ns for PRTC-B, and 30 ns for ePRTC. The MTIE is equivalent to the peak-to-peak value of the dTE. There are three basic ways to measure it: Measure the time interval error (TIE) for the 1PPS output at one sample per second and without any low-pass filtering. Calculate the MTIE and TDEV from that and compare those series to the G.8272 masks (or G.8272.1 for ePRTC clocks). Measure the TIE for the 2048-kHz, 2048-kbps, and 1544-kbps outputs passed through a 10-Hz low-pass measurement filter, with a maximum sampling time of 1/30 second. Calculate the MTIE and TDEV and compare them to the masks for G.8272 (or G.8272.1 for ePRTC clocks). Measure the 2wayTE for the PTP messages. These measurements are then passed through a moving-average low-pass filter of at least 100 consecutive TE samples. The sample will be based on the PTP packet rate, which is 16 per second for G.8275.1. Calculate the MTIE and TDEV and compare them to the masks for G.8272 (or G.8272.1 for ePRTC clocks). The jitter requirements for frequency input and outputs are defined in the PRC specification of G.811 or the ePRC G.811.1 specification. Holdover Testing There are no official holdover performance requirements for PRTC-A and PRTC-B, although the ePRTC recommendations do have a holdover requirement (ePRTC clocks require connection to an atomic frequency standard to meet their expected levels of performance). As an example, the requirement for holdover of an ePRTC-A is that it must be accurate to UTC within a margin increasing linearly from 30 ns to 100 ns over a 14-day period (after running it for 30 days in normal