Blocking "Unknown" Callers - Aastra 9617 Online User's Manual

Blocking "Unknown" callers

Enabling the Block Unknown Call option blocks all calls
that have a Caller ID of "unknown." A caller will be listed
as "unknown" if the telephone company has no
information for them. Blocked calls rings once, unless you
have enabled the Suppress First Ring option.
For information on how to enable this option, refer to the
"General tab" subtopic on The M9617 Configuration
Properties dialog box on page 92.
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