In production networks, there are sometimes special scenarios, such as in Brownfield networks, where using Full Timing Support (FTS; ITU-T G.8271.1/G.8275.1) throughout the entire network is not an option, and using Partial Timing Support (PTS; ITU-T G.8271.1/G.8275.2) for the entire network is also not desirable.
In these scenarios, both PTP profiles must coexist on the same network.
This requires a Telecom Boundary Clock (T-BC) that can translate between the two profiles while meeting the specifications of each, a feature called a Profile Interworking Function (IWF).
These tests aim to validate T-BC-1's ability to translate between FTS and PTS and vice versa.

For all of these different combinations and iterations, except for one, the Microchip TimeProvider® 4500 was utilized as the Telecom Grandmaster (T-GM), sending either FTS or PTS downstream towards the first Telecom Boundary Clock (T-BC-1); T-BC-1 served as the IWF gateway for the translation of each respective PTP profile, where it would then be converted and sent downstream towards T-BC-2. T-BC-2's output was then measured by either the Calnex Paragon neo, Paragon neo-A, or the Keysight Time Sync Analyzer.
For the ITU-T G.8275.1 to ITU-T G.8275.2 (FTS to PTS), the T-GM provided ITU-T G.8275.1 traffic towards T-BC-1. T-BC-1 then translated FTS to PTS and sent it downstream to T-BC-2, where its output was measured.
For the ITU-T G.8275.2 to ITU-T G.8275.1 (PTS to FTS), the process was the opposite: the T-GM transmitted PTS traffic to T-BC-1, which translated it to FTS and sent it to T-BC-2, where the output was again measured.
For the limit metrics of these two test cases, we have chosen the constant Time Error (cTE) and the peak-to-peak two-way low-pass-filtered dynamic Time Error (dTE_L) of 200ns.
For FTS T-BCs, the cTE for class C is defined as +/- 10ns, as per ITU-T G.8273.2; for PTS T-BCs, only classes A and B are defined for the cTE, +/- 50ns for class A and +/- 20ns for class B, as per ITU-T G.8273.4; this gives us limits of +/- 60ns for one class C FTS T-BC and one class A PTS T-BC and the tighter limit of +/- 30ns for one class C FTS T-BC and one class A PTS T-BC.
For FTS to PTS, the cTE of 14 out of the 17 different combinations was within the limit of +/- 30ns, with some being less than +/- 20ns and some even less than +/-10 ns; the other three iterations were within the limits of +/- 60ns. All combinations were well within the 200ns peak-to-peak limit for the dTE_L.
For PTS to FTS, the cTE of three out of 12 different combinations was within the limit of +/- 30ns, with one combination being sub +/- 20ns and two being sub +/- 10ns; the remaining nine combinations were all well within the limit of +/- 60ns. For the peak-to-peak dTE_L, all combinations were, once again, more than well within the limits of 200ns.