[VDSL]Sbalzi SNR ad intervalli regolari

[-Yara-]

Ciao, fino a ieri andava tutto bene, poi oggi, senza cambiare nulla, ho degli sbalzi dell'SNRm in downstream.

Passa da cosi:

============================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 8b
            Traffic Type:   PTM Mode
             Link Uptime:   0 day: 1 hour: 16 minutes
============================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:      8.954 Mbps       66.741 Mbps
    Actual Net Data Rate:      8.955 Mbps       66.742 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        5.8 dB            6.1 dB 
            Actual Delay:          0 ms              0 ms
          Transmit Power:      - 8.2 dBm          18.5 dBm
           Receive Power:        0.0 dBm           7.6 dBm
              Actual INP:       55.0 symbols      59.0 symbols
       Total Attenuation:        0.5 dB           11.0 dB
Attainable Net Data Rate:      8.955 Mbps       68.136 Mbps
============================================================================
      VDSL Band Status    U0      U1      U2      U3      D1      D2      D3
  Line Attenuation(dB):  4.4    27.2     N/A     N/A    13.9    36.8     N/A   
Signal Attenuation(dB):  4.4    26.0     N/A     N/A    11.5    36.5     N/A   
        SNR Margin(dB):  5.8     5.8     N/A     N/A     6.3     5.8     N/A   
   Transmit Power(dBm):-13.1   -10.0     N/A     N/A    18.3     7.6     N/A

a cosi:

============================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 8b
            Traffic Type:   PTM Mode
             Link Uptime:   0 day: 1 hour: 21 minutes
============================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:      8.954 Mbps       66.741 Mbps
    Actual Net Data Rate:      8.955 Mbps       66.742 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        5.8 dB            5.1 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:      - 8.2 dBm          18.5 dBm
           Receive Power:        0.0 dBm           7.6 dBm
              Actual INP:       55.0 symbols      59.0 symbols
       Total Attenuation:        0.5 dB           11.0 dB
Attainable Net Data Rate:      8.955 Mbps       66.359 Mbps
============================================================================
      VDSL Band Status    U0      U1      U2      U3      D1      D2      D3
  Line Attenuation(dB):  4.4    27.2     N/A     N/A    13.9    36.8     N/A   
Signal Attenuation(dB):  4.4    26.0     N/A     N/A    11.5    36.5     N/A   
        SNR Margin(dB):  5.8     5.8     N/A     N/A     5.1     5.1     N/A   
   Transmit Power(dBm):-13.1   -10.0     N/A     N/A    18.3     7.6     N/A   
============================================================================

Entrambe le configurazioni durano circa VENTI secondi, il che mi fa pensare ad un disturbo intermittente.

Ho anche un adsl su un altro doppino, ed anche quella varia in maniera regolare, ma di 0.1db non di 1db intero.

Che fare? Cosa potrebbe essere
Escludo qualsiasi problema all'impianto telefonico di casa.

Grazie