| 摘要 |
<P>PROBLEM TO BE SOLVED: To find how many nuisance calls are received from a caller phone number after registering the caller phone number in a nuisance call database. <P>SOLUTION: A private branch exchange has: a nuisance call database for, when receiving an instruction of registration of a caller phone number recognized as a number of a nuisance caller from any of plurality of extension telephones, registering the caller phone number with a predetermined monitoring period and an extension number of an extension telephone instructing the registration of the caller phone number; and a control unit for counting the number of calls received from the caller phone number via a public network during the monitoring period registered with the caller phone number in the nuisance call database. <P>COPYRIGHT: (C)2012,JPO&INPIT |
