Firstly, report the voice problem to your supplier. There is likely to be a failing joint at some point. A single leg fault will affect phone colls and cause loss of service however, with ADSL/VDSL it will just cause a significant drop in speed.
At the bottom of the page there is a link to Broadband Ping Monitoring
and if yor modem/router is compatible you can download DSL Stats from http://dslstats.me.uk/
and leave that running on your PC.
M H C
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