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.