Patent ID: 7177399

Claim:
A method of providing a routing key for routing an emergency call from a packet-based communications network node to an emergency services network node in a switched telephone network, the packet-based communications network comprising an access part and a core part, said method comprising the steps, performed at a node of the core part of the packet-based communications network, of: (i) requesting, during the emergency call, a node in the access part of the packet-based communications network to determine a current geographical location of a terminal from which the emergency call originates; (ii) receiving information about the determined current geographical location from the node in the access part of the packet-based communications network; (iii) generating a routing key on the basis of the received information and pre-specified information about geographical locations served by particular emergency service network nodes; and (iv) storing said generated routing key together with the received information at the node in the core part of the packet-based communications network.