A carrier of telecommunications traffic provides different call treatment when the carrier receives a code indicative of that carrier as opposed to when no code has been entered. For example, by entering the access code of the telecommunications carrier, a caller may invoke a special service. One such...http://www.google.de/patents/US5553129?utm_source=gb-gplus-sharePatent US5553129 - Method and apparatus for treating calls based on receipt of telecommunications carrier code indications
