TIPTEL 215 clip Bedienungsanleitung Seite 157

No call number displayed when a call is
received
If all of the above suggestions do not resolve your problem, use a straightened paper clip to press RESET on the back of
the tiptel 215 clip. Insert the paper clip inclined until You reach the button within the housing. Thus, you reset the answering
machine.
Appendix
Network operator or PABX does not support the
function or function is not authorised.
The caller has suppressed his call number or
has a secret number.
The call comes from a public telephone.
The call is made via a telephone network that
does not support transferring call numbers.
65
Check with network operator or PABX as to
whether function is supported or needs to be
authorised.
UK