Patent ID: 8223754

Claim:
An apparatus comprising: a memory; and a processor in communication with the memory, the memory including computer code executable with the processor, wherein the computer code is executable to: receive a call over a Public Switched Telephone Network (PSTN) at the apparatus, the call initiated from a Voice over Internet Protocol (VoIP) adapter; store a node identifier of the apparatus and a call detail of the call in a registry service in response to receipt of the call over the PSTN, wherein the call detail of the call includes proof of knowledge of the call initiated over the PSTN, the call detail of the call is associated in the registry service with the node identifier of the apparatus, and wherein the registry service is accessible by a plurality of VoIP adapters over a network for storage and retrieval of values by the VoIP adapters, the VoIP adapters including the VoIP adapter that initiated the call over the PSTN; determine, at the apparatus, a dial sequence at which the apparatus was reached in the call over the PSTN based on a match of the call detail of the call stored in the registry service with a corresponding call detail generated at the VoIP adapter, wherein the dial sequence includes digits dialed to initiate the call; and advertise that the apparatus is reachable over VoIP at the dial sequence in response to the determination of the dial sequence at which the apparatus was reached over the PSTN.