In conjunction with a data communication network carrying multiple telephony signals and allowing for connection of telephone sets, a system and method in which two external feeders connect to the data network at two distinct points via two distinct devices. The data network can be based on dedicated...http://www.google.es/patents/US7738453?utm_source=gb-gplus-sharePatente US7738453 - Telephone system having multiple sources and accessories therefor
Telephone system having multiple sources and accessories therefor
