Handling emergency calls using EAP
A user (terminal) is allowed to make an emergency voice-over-Internet Protocol (VoIP) phone call through an access network, such as a wireless local area network (WLAN) using Extensible Authentication Protocol (EAP). The emergency call can be made with or without authentication credentials and is identified by the user's terminal transmitting a Network Access Identifier (NAI) having a user part and/or realm part that indicates the emergency nature of the call, such as [email protected]. In response to such an NAI, the caller can be immediately granted limited authentication for the purpose of connecting to an emergency call center. Alternatively, the user (terminal) can be authenticated through networks supporting emergency calls, such as the user's home network, if the terminal indicates to the access network authentication server a preference or requirement for using such networks. The call can be routed to the emergency call center either directly or via one or more intermediary networks, such as networks that support emergency VoIP phone calls.
1. A method for placing an emergency voice-over-Internet Protocol (VoIP) call from a terminal via a preferred network, the method comprising:
receiving, at an access network that is disparate from a home network of the terminal, an identity response from the terminal that includes preference data indicative of at least one intermediary network that supports emergency calling;
performing authentication between an authentication, authorization and accounting (AAA) server associated with the access network and an AAA server associated with the home network via the at least one intermediary network; and
connecting an emergency call initiated by the terminal to an emergency center via the at least one intermediary network if the authentication is successful.
2. The method of claim 1 , further comprising, identifying a next AAA server associated with the at least one intermediary network in a path leading to the AAA server associated with the home network.
3. The method of claim 2 , wherein the receiving includes receiving a Network Access Identifier (NAI) decorated with realm information of the home network and realm information of the at least one intermediary network.
4. The method of claim 3 , further comprising, forwarding the NAI to the next AAA server.
5. The method of claim 4 , further comprising, modifying the NAI at the next AAA server to identify the path leading to the AAA server associated with the home network.
6. The method of claim 1 , further comprising, transmitting an Extensible Authentication Protocol (EAP) Identity Request to the terminal.
7. The method of claim 1 , further comprising, storing a database listing of intermediary network operators that support emergency calling.
8. The method claimed in claim 1 , further comprising, transmitting to the emergency center, via the at least one intermediary network, information indicating a location of an access point of the access network, to which the terminal connects.
9. The method claimed in claim 1 , further comprising, communicating an access-challenge message packet that encapsulates an EAP identity request containing an identity of one or more intermediary networks that are capable of handling emergency calls.
10. A system for controlling placement of an emergency voice-over-Internet Protocol (VoIP) call from a terminal in communication with an access network, the system comprising:
an access point, within the access network, that receives an identity response from the terminal that comprises preference data indicative of one or more intermediary networks that support emergency calling associated with a VoIP call, the access network is different from a home network to which the terminal subscribes; and
an authentication, authorization and accounting (AAA) server, local to the access network, that performs authentication of the terminal with an AAA server associated with the home network via the one or more intermediary networks, an emergency call initiated by the terminal is routed to an emergency center via the one or more intermediary networks if the authentication is successful.
11. The system of claim 10 , wherein the access point communicates an Extensible Authentication Protocol (EAP) identity request to the terminal.
12. The system of claim 10 , wherein the identity response includes a Network Access Identifier (NAI) comprising information that identifies at least one of a user of the terminal, the home network, or the one or more intermediary networks that are selected by the user.
13. The system of claim 12 , wherein the AAA server, local to the access network, identifies a disparate AAA server, associated with one of the one or more intermediary networks, to which the identity response is forwarded.
14. The system of claim 13 , wherein the AAA server, local to the access network, forwards the identity response to the disparate AAA server.
15. The system of claim 13 , wherein the disparate AAA server modifies the NAI to identify a next AAA server in a path leading to AAA server associated with the home network.
16. The system of claim 13 , wherein the disparate AAA server forwards the modified NAI to the next AAA server.
17. The system of claim 10 , further comprising, a database that stores a list of intermediary network operators, which support emergency calling and with which an operator of the access network has a roaming agreement.
18. The system of claim 17 , wherein the AAA server local to the access network, generates an access-challenge message packet that encapsulates an EAP identity request, which includes identities of the list of intermediary network operators, the EAP identity request is transmitted to the terminal.
19. A system for controlling placement of an emergency voice-over-Internet Protocol (VoIP) call from a terminal roaming within access network that is not the terminal's home network, the system comprising:
means for receiving, within the access network, information from the terminal indicating a preference for employing an intermediary network that supports an emergency call; and
means for authenticating the terminal with an AAA server associated with the terminal's home network via the intermediary network.
20. The system of claim 19 , wherein the means for authenticating allows the terminal to establish the emergency VoIP call with an emergency center via the intermediary network, if the authentication is successful.