Method for monitoring voicemail calls using adsi capable cpe
CA 2235492 C · Owner: Nortel Networks Corporation · Inventors: Gordon, Ian R.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A Central Office voicemail system permits a customer to monitor incoming calls and decide whether or not he wishes to take the call. When a call is made to a called party (customer) and the called party does not answer the phone the call is transferred to voicemail in the usual way. Additionally a special ringing tone is applied automatically by the Central Office to the called party line. This has the effect of alerting the called party to the fact that the caller has been transferred to voicemail. The called party can then monitor the message being left simply by lifting his phone and, if he wants to talk to the caller he simply, carries out a hookswitch flash. Alternatively with a, …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed April 21, 1998 and granted January 28, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 21, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 21, 2020.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.