Method of completing long distance pots calls with ip telephony endpoints
CA 2269261 C · Owner: At&T Corp. · Inventors: Ramamurthy, Ram S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
When a calling party calls a called party on the public-switched telephone network (PSTN) a database common to both the PSTN and an Internet Protocol (IP) network is accessed to determine whether the called telephone line is currently active on the IP network. That database maintains a record for each user who is currently active on the IP network through an Internet Service Provider (ISP). In addition each record contains information identifying the particular user logged into the network on that line an indication whether the telephone line is IP telephony capable an indication whether that line is currently active on an IP telephony call on an Internet Telephony network (ITN) and the IP …
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 19, 1999 and granted December 24, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 2021.
- 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.