The present invention enables an alert message and the display of calling party identity on all on-hook phones associated with an extension sharing the same phone number, when one phone is off-hook and in use. In one exemplary embodiment, this capability enables all other members of a household to receive...http://www.google.es/patents/US7664252?utm_source=gb-gplus-sharePatente US7664252 - Method and apparatus for sending alerts to internet protocol phones
Method and apparatus for sending alerts to internet protocol phones
