Emergency call back for session initiation protocol sessions
An Address Resolution Protocol (ARP) process receives a first Internet Protocol (IP) address that is associated with a Media Access Control (MAC) address of a communication endpoint. A first Session Initiation Protocol (SIP) INVITE for an emergency call request is received from the communication endpoint. The ARP process receives a second IP address that is associated with the MAC address of the communication endpoint. A second SIP INVITE is received that is a request for an emergency call back. The second SIP INVITE is routed to the communication endpoint based on the second IP address associated with the MAC address of the communication endpoint to reestablish the emergency call with the communication endpoint.
1. An apparatus comprising:
a microprocessor; and
a computer readable medium, coupled with the microprocessor and comprising microprocessor readable and executable instructions that cause the microprocessor to:
receive, from an Address Resolution Protocol (ARP) process, a first Internet Protocol (IP) address that is associated with a Media Access Control (MAC) address of a communication endpoint;
receive a first Session Initiation Protocol (SIP) INVITE that is an emergency call request from the communication endpoint;
send the first SIP INVITE to request the emergency call to a communication manager or a gateway;
receive, from the ARP process, a second IP address that is associated with the MAC address of the communication endpoint,
receive a second SIP INVITE that is a request for an emergency call back from the communication manager or gateway, wherein the second SIP INVITE comprises the first IP address of the communication endpoint; and
route the second SIP INVITE to the communication endpoint based on the second IP address associated with the MAC address of the communication endpoint.
2. The apparatus of claim 1 , wherein the first IP address is from a first network and the second IP address is from a second network and wherein the first IP address is different from the second IP address.
3. The apparatus of claim 1 , wherein the instructions cause the microprocessor to associate the MAC address with the emergency call.
4. The apparatus of claim 1 , wherein the emergency call back request results from the communication endpoint moving between a first wireless network and a second wireless network, which causes a communication session for the emergency call to be disconnected prematurely.
5. The apparatus of claim 1 , wherein the second SIP INVITE is routed to the communication endpoint based on sending the first SIP INVITE to request the emergency call.
6. The apparatus of claim 5 , wherein the first SIP INVITE is sent regardless of whether a user is authenticated or not.
7. The apparatus of claim 1 , wherein instructions cause the microprocessor to receive a SIP out-of-dialog message addressed to the communication endpoint using the first IP address and route the SIP out-of-dialog message to the communication endpoint using the second IP address.
8. The apparatus of claim 1 , wherein the received first IP address is based on the first SIP INVITE and wherein a first ARP request is automatically sent in response to receiving the first SIP INVITE.
9. The apparatus of claim 8 , wherein the first ARP request is automatically sent, regardless of a state of an ARP table for the ARP process.
10. The apparatus of claim 1 , wherein the first SIP INVITE comprises the MAC address of the communication endpoint, wherein the second SIP INVITE comprises the MAC address of the communication endpoint, and wherein the instructions cause the microprocessor to use the MAC address of the communication endpoint to route the second SIP INVITE to the communication endpoint.
11. A method comprising:
receiving, by a processor, from an Address Resolution Protocol (ARP) process, a first Internet Protocol (IP) address that is associated with a Media Access Control (MAC) address of a communication endpoint;
receiving, by the processor, a first Session Initiation Protocol (SIP) INVITE that is an emergency call request from the communication endpoint;
sending, by the processor, the first SIP INVITE to request the emergency call to a communication manager or a gateway;
receiving, by the processor, from the ARP process, a second IP address that is associated with the MAC address of the communication endpoint;
receiving, by the processor and from the communication manager or gateway, a second SIP INVITE that is a request for an emergency call back, wherein the second SIP INVITE comprises the first IP address of the communication endpoint; and
routing, by the processor, the second SIP INVITE to the communication endpoint based on the second IP address associated with the MAC address of the communication endpoint.
12. The method of claim 11 , wherein the processor associates the MAC address with the emergency call.
13. The method of claim 11 , wherein the emergency call back request results from the communication endpoint moving between a first wireless network and a second wireless network, which causes a communication session for the emergency call to be disconnected prematurely.
14. The method of claim 11 , wherein the second SIP INVITE is routed to the communication endpoint based on sending the first SIP INVITE to request the emergency call.
15. The method of claim 11 , wherein the first ARP request is automatically sent, regardless of a state of an ARP table for the ARP process.
16. The method of claim 11 , wherein the received second IP address associated with the MAC address is in an IP packet with a SIP BYE message for the emergency call.
17. The method of claim 11 , wherein the received first IP address associated with the MAC address is in an IP packet with a SIP message and wherein a first ARP request is sent automatically in response to the IP packet comprising the SIP message.
18. The method of claim 11 , wherein the processor receives a SIP out-of-dialog message addressed to the communication endpoint using the first IP address and routes the SIP out-of-dialog message to the communication endpoint using the second IP address.
19. The method of claim 11 , wherein the first SIP INVITE comprises the MAC address of the communication endpoint, wherein the second SIP INVITE comprises the MAC address of the communication endpoint, and wherein the processor uses the MAC address of the communication endpoint to route the second SIP INVITE to the communication endpoint.
20. An apparatus comprising:
a microprocessor; and
a computer readable medium, coupled with the microprocessor and comprising microprocessor readable and executable instructions that cause the microprocessor to:
a first Internet Protocol (IP) address associated with a Media Access Control (MAC) address of a communication endpoint;
receive an emergency call request from the communication endpoint;
send the emergency call request to a communication manager or gateway,
receive a second IP address associated with the MAC address of the communication endpoint;
receive, from the communication manager or gateway, a request for an emergency call back; and
route the request for the emergency call back to the communication endpoint based on the second IP address associated with the MAC address of the communication endpoint.