Asking on behalf of a friend, he has ADSL2+ with orange achieving around 8Mbps normally, phone is with post office. Recently he has been receiving a lot of unwanted phone calls (withheld number etc) and over the last few days incoming calls have sometimes been causing the broadband to drop entirely when the phone is picked up. he's now at around 5Mbit. He has a filtered faceplate rather than a dangly filter. He also says there is no audible noise on the line during calls.
Clearly there's a problem because the broadband shouldn't be conking out when the phone is picked up. How should he proceed with this and who does he take it up with? (orange or postoffice).
EDIT1: after further discussion, he seems to think the router (orange brightbox (1?)) is rebooting entirely when a bad call comes in.
