A framework for supporting 911 service in a PBX LAN: Protocol requirements and analysis

IP Telephony is being increasingly viewed as an attractive option to the deployment of traditional telephony services from an IP perspective. In the Public Switched Telephone Network, 911 services are handled by a dedicated, point-to-point analog network infrastructure. In contrast, 911 in IP telephony is constrained by IP's flat addressing scheme, inherent dynamicity in network topology and IP's best-effort service model. To serve crucial E911 needs of accurate assistance dispatch with callback facility in IP Telephony, new methodologies must be outlined.; This paper investigates ways of resolving location information of an IP telephony 911 caller and proposes a novel option to convey geographic location information parameters of connected hosts by extending DHCP protocol. The case scenario of Voice over IP in Local Area Networks is used as the basis for our proposal and, in specific, University of Missouri Kansas City's Voice Over IP network has been studied for possible deployment of this approach.