For my company I organise the broadband service for our remote users and the company picks up the tab.
Now with one such installation we have a problem with silent calls that come in around midnight almost ever night. Having tried every option thrown at us by Zen, none of which worked, decided to have the number changed specifying that the number had to be ex-directory and not given to directory enquiry services.
On the very day the number was changed, and even before a select few were given the "new" number, a further nuisance silent call came in. Zen seemed to be entirely baffled by this turn of events and have gone away to scratch their heads.
This is all very well but another disturbed night is on the horizon. Anyone with any ideas of how to crack this problem?
FWiW, you are not alone in experiencing phantom telephone calls. The Fritz!Box 7390 modem/router suffered from this problem up until about a year ago. The manufacturer's response was as follows:
Thank you very much for the enquiry you submitted to AVM Support.
Ghost calls and DSL disconnects parallel to incoming telephone calls occur
due to electrical impulses. The latter mostly is caused by a wrong cabling
with an analog landline.
Verify that only the DSL splitter is attached to the main telephone socket
and that no other terminal devices (e.g. telephone, fax machines etc.) and
no other telephone sockets (e.g. via extension leads) are connected to the
main socket. Connect any terminal devices to the extensions of the
FRITZ!Box.
The problem disappeared after I double-filtered the telephone line. I replaced the 7390 with a 7490 about 6 months ago and it has standard telephone filtering and there haven't been any issues. I am with ZEN both for BB and phone.
FWIW, the 7490 allows unknown and withheld calls to be diverted to an answerphone. The ring doesn't ring so late night calls are not an issue. The Fritz!Box also sends me an e-mail transcript of all answerphone messages for me to review as and when.