One-Number-Service (ONS) allows a subscriber to keep a single Directory Number when relocating to a different access point among one or more interconnected telecommunication systems. According to one aspect of the invention, a signaling packet for a call setup to a ported number is intercepted at an...http://www.google.fr/patents/US6438223?utm_source=gb-gplus-shareBrevet US6438223 - System and method for local number portability for telecommunication networks
System and method for local number portability for telecommunication networks
