improve the slave accuracy to < 100ns

[Lam Phung]

hi guys,
i'm tesing with ptpd2.3.1_rc5 (hardware timestamp is supported on my device) , i had a good accuracy in my lab with <100ns, the log bellow for further information
2016-06-12 16:56:27.062714, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000103, 0.000000000, -0.000000009, -228.238508357, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000009, 0.000010648
2016-06-12 16:56:28.062715, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, 0.000000086, 0.000000000, 0.000000181, -233.388529611, S, 0.000000000, 0, 0.000000008, 57, -220, 7, 0.000000181, 0.000010648
2016-06-12 16:56:29.062714, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, 0.000000081, 0.000000000, -0.000000019, -229.088527035, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000019, 0.000010648
2016-06-12 16:56:30.062718, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, 0.000000041, 0.000000000, 0.000000101, -225.038534269, S, 0.000000000, 0, 0.000000008, 57, -220, 7, 0.000000101, 0.000010648
2016-06-12 16:56:31.062715, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, 0.000000046, 0.000000000, -0.000000009, -222.988523172, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000009, 0.000010648
2016-06-12 16:56:32.062712, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, 0.000000011, 0.000000000, 0.000000031, -220.688532625, S, 0.000000000, 0, 0.000000008, 57, -220, 7, 0.000000031, 0.000010648
2016-06-12 16:56:33.062710, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000019, 0.000000000, -0.000000069, -220.138534181, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000069, 0.000010648
2016-06-12 16:56:34.062715, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, 0.000000006, 0.000000000, 0.000000081, -221.088533115, S, 0.000000000, 0, 0.000000008, 57, -220, 7, 0.000000081, 0.000010648
2016-06-12 16:56:35.062715, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000014, 0.000000000, -0.000000109, -220.788531948, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000109, 0.000010648
2016-06-12 16:56:36.062711, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000034, 0.000000000, 0.000000041, -221.488532898, S, 0.000000000, 0, 0.000000008, 57, -220, 7, 0.000000041, 0.000010648
2016-06-12 16:56:37.062716, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000044, 0.000000000, -0.000000129, -223.188525039, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000129, 0.000010648
2016-06-12 16:56:38.062718, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000049, 0.000000000, 0.000000031, -225.388536897, S, 0.000000000, 0, 0.000000008, 57, -220, 7, 0.000000031, 0.000010648
2016-06-12 16:56:39.062710, slv, 00b0aefffe01c9f3(unknown)/1, 0.000000000, -0.000000049, 0.000000000, -0.000000129, -227.838541993, S, 0.000000000, 0, 0.000000008, 57, -220, 7, -0.000000129, 0.000010648

But when i connect my device to the real network,after about 2 minutes, it can't be reach to <1000ns:
2016-06-10 12:30:13.255428, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, 0.000003161, 0.003195706, 0.001186472, -13020.260345571, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001186472, 0.003195706
2016-06-10 12:30:13.317917, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000003423, 0.003195706, 0.001176072, -13010.382549315, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001176072, 0.003195706
2016-06-10 12:30:13.380415, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000009682, 0.003195706, 0.001173952, -13021.077270050, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001173952, 0.003195706
2016-06-10 12:30:13.442969, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, 0.000016927, 0.003195706, 0.001229292, -13051.332242026, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001229292, 0.003195706
2016-06-10 12:30:13.505422, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, 0.000019272, 0.003195706, 0.001178642, -12998.390363211, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001178642, 0.003195706
2016-06-10 12:30:13.567925, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000003292, 0.003195706, 0.001184162, -12938.210768043, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001184162, 0.003195706
2016-06-10 12:30:13.630411, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000008102, 0.003195706, 0.001169022, -12948.498658639, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001169022, 0.003195706
2016-06-10 12:30:13.692923, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000009667, 0.003195706, 0.001181032, -12973.811337810, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001181032, 0.003195706
2016-06-10 12:30:13.755420, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000005997, 0.003195706, 0.001176362, -13004.025958608, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001176362, 0.003195706
2016-06-10 12:30:13.817915, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, -0.000010222, 0.003195706, 0.001172582, -13022.765368016, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001172582, 0.003195706
2016-06-10 12:30:13.880449, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, 0.000004497, 0.003195706, 0.001205802, -13054.706215479, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001205802, 0.003195706
2016-06-10 12:30:13.942930, slv, 00b0aefffe03d054(unknown)/1, 0.001184695, 0.000012101, 0.003195706, 0.001187792, -13040.645661660, S, 0.001040430, 192337, -0.000006558, 13522, -11408, 2765, 0.001187792, 0.003195706
i see ptpd also support many filters but i don't know where i should start from. Could you give me some advice for reaching good accuracy, please ?