Does the DSL "Downstream SNR offset" value only have an effect on some router models or some software versions ?
I am on a long line and its target SNR appears to be 12dB (if I were to keep the router permanently powered on this would probably go down but I prefer to turn it off at night).
I am running OpenWrt 18.06.5 r7897-9d401013fc on a BTHub5a.
Choosing any Downstream SNR offset value between -6 and +6 dB has no effect on the data rate. I was expecting a 10 or 20% speed improvement with a +6dB value (at a cost of poorer line stability).
"dsl_control status" report with Downstream SNR offset of -6dB
ATU-C Vendor ID: Infineon 113.200
ATU-C System Vendor ID: 00,00,30,30,30,30,00,00
Chipset: Lantiq-VRX200
Firmware Version: 5.8.0.11.1.1
API Version: 4.17.18.6
XTSE Capabilities: 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0
Annex: A
Line Mode: G.992.1 (ADSL)
Profile:
Line State: UP [0x801: showtime_tc_sync]
Forward Error Correction Seconds (FECS): Near: 4472 / Far: 4
Errored seconds (ES): Near: 119 / Far: 4
Severely Errored Seconds (SES): Near: 0 / Far: 3
Loss of Signal Seconds (LOSS): Near: 0 / Far: 2
Unavailable Seconds (UAS): Near: 211 / Far: 211
Header Error Code Errors (HEC): Near: 595 / Far: 0
Non Pre-emtive CRC errors (CRC_P): Near: 0 / Far: 0
Pre-emtive CRC errors (CRCP_P): Near: 0 / Far: 0
Power Management Mode: L0 - Synchronized
Latency [Interleave Delay]: 8.0 ms [Interleave] 8.0 ms [Interleave]
Data Rate: Down: 2.144 Mb/s / Up: 448 Kb/s
Line Attenuation (LATN): Down: 59.4 dB / Up: 31.5 dB
Signal Attenuation (SATN): Down: 55.6 dB / Up: 31.5 dB
Noise Margin (SNR): Down: 11.5 dB / Up: 17.0 dB
Aggregate Transmit Power (ACTATP): Down: 18.0 dB / Up: 12.6 dB
Max. Attainable Data Rate (ATTNDR): Down: 2.176 Mb/s / Up: 1.004 Mb/s
Line Uptime Seconds: 20222
Line Uptime: 5h 37m 2s
"dsl_control status" report with Downstream SNR offset of +6dB (after doing a full_init)
Slightly slower as it is later in the evening.
ATU-C Vendor ID: Infineon 113.200
ATU-C System Vendor ID: 00,00,30,30,30,30,00,00
Chipset: Lantiq-VRX200
Firmware Version: 5.8.0.11.1.1
API Version: 4.17.18.6
XTSE Capabilities: 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0
Annex: A
Line Mode: G.992.1 (ADSL)
Profile:
Line State: UP [0x801: showtime_tc_sync]
Forward Error Correction Seconds (FECS): Near: 4294962406 / Far: 0
Errored seconds (ES): Near: 121 / Far: 4
Severely Errored Seconds (SES): Near: 0 / Far: 3
Loss of Signal Seconds (LOSS): Near: 0 / Far: 2
Unavailable Seconds (UAS): Near: 243 / Far: 243
Header Error Code Errors (HEC): Near: 1 / Far: 0
Non Pre-emtive CRC errors (CRC_P): Near: 0 / Far: 0
Pre-emtive CRC errors (CRCP_P): Near: 0 / Far: 0
Power Management Mode: L0 - Synchronized
Latency [Interleave Delay]: 4.0 ms [Interleave] 8.0 ms [Interleave]
Data Rate: Down: 1.920 Mb/s / Up: 448 Kb/s
Line Attenuation (LATN): Down: 59.3 dB / Up: 31.5 dB
Signal Attenuation (SATN): Down: 55.5 dB / Up: 31.5 dB
Noise Margin (SNR): Down: 13.5 dB / Up: 17.0 dB
Aggregate Transmit Power (ACTATP): Down: 17.6 dB / Up: 12.5 dB
Max. Attainable Data Rate (ATTNDR): Down: 2.048 Mb/s / Up: 984 Kb/s
Line Uptime Seconds: 987
Line Uptime: 16m 27s