Velocità di connessione in diminuzione

[John P.]

Salve a tutti,
ho un problema un po' strano con un'ADSL Alice 20, che fino a poco tempo fa andava a meraviglia.
Praticamente, dopo qualche ora che il modem/router è acceso, la velocità diminuisce paurosamente, e il ping da circa 20 ms mi passa a 750 e anche più.
L'unica soluzione è quella di riavviare il modem, ma dopo un po' tutto torna come prima.
Questi i dati di connessione:

[TABLE="class: tableBg, width: 640"]
[TR]
[TD="class: trScura, width: 100%, bgcolor: #53669E, colspan: 6"]Statistiche Connessione[/TD]
[/TR]
[TR]
[TD="class: trChiara, width: 100%, bgcolor: #B6C4E9, colspan: 6"]ADSL[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Stato[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 4"]Attivo[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Sistema di trasmissione[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 4"]ADSL2+[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Modalità[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 4"]Fast[/TD]
[/TR]
[TR]
[TD="class: tdBianca, width: 40%, bgcolor: #000000, colspan: 2"] [/TD]
[TD="class: tdScura, width: 30%, bgcolor: #53669E, colspan: 2"]Downstream[/TD]
[TD="class: tdScura, width: 30%, bgcolor: #53669E, colspan: 2"]Upstream[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Rate (kbps)[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]22239[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]1215[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]SNR Margin (dB)[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]4.7[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]7.3[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Attenuation (dB)[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]12.5[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]8.7[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Impulse Noise Protection (INP)[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Output Power[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0.0[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]12.6[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Super Frames[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]3678489[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]511379[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Super Frames Errors[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]28[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]15[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]RS Words[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]3221377[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]RS Correctable Errors[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]RS Uncorrectable Errors[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[/TR]
[TR]
[TD="class: tdBianca, bgcolor: #000000, colspan: 6"] [/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Total ES[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]23[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]15[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Total SES[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]0[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E, colspan: 2"]Total UAS[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]49[/TD]
[TD="class: tdBianca, bgcolor: #000000, colspan: 2"]49[/TD]
[/TR]
[TR]
[TD="class: trChiara, width: 100%, bgcolor: #B6C4E9, colspan: 6"]ATM PVC[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E"]VPI/VCI[/TD]
[TD="class: tdScura, bgcolor: #53669E"]CRC Errors[/TD]
[TD="class: tdScura, bgcolor: #53669E"]SAR Timeouts[/TD]
[TD="class: tdScura, bgcolor: #53669E"]Oversized SDUs[/TD]
[TD="class: tdScura, bgcolor: #53669E"]Short Packet Errors[/TD]
[TD="class: tdScura, bgcolor: #53669E"]Length Errors[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E"]8/35[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[/TR]
[TR]
[TD="class: tdScura, bgcolor: #53669E"]8/36[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[TD="class: tdBianca, bgcolor: #000000"]0[/TD]
[/TR]
[/TABLE]

(se l'immagine dà caselle nere, evidenziatele col cursore)

Un grazie di cuore a chi mi vorrà aiutare!!