Patent ID: 8750290

Claim:
An endpoint telephone device for ensuring accessibility to emergency service via VoIP or via PSTN comprising: a packet network interface to be connected to a packet network; a telephone line interface to be connected to a PSTN telephone line; a telephone set interface to be connected to a telephone set; and a controller configured to receive information from a VoIP service provider, the VoIP service provider providing VoIP services to VoIP service users, indicating accessibility of the emergency service on the packet network interface where required, to sense the telephone line interface to verify accessibility to the emergency service over the telephone line interface, and to route calls to the packet network interface or the telephone line interface and restrict VoIP calls dependent on the information and sensed accessibility, emergency service calls being routed to the PSTN telephone line when the emergency service is not available on the packet network interface; and programmable bits that can be set by the VoIP service provider and used to determine the endpoint's behavior, including its decision about whether to route a call to the VoIP service provider; and further the endpoint device is configured to supply the VoIP service provider's server with required information in relation to the status of the endpoint's PSTN connection to enable the VoIP service provider's server to make a routing decision.