On Study of VoIP-based Emergency Call Service

• Main Authors: Kai-Min Huang, 黃楷珉
• Other Authors: Yung-Chang Wong
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/14471002475973412704

碩士 === 靜宜大學 === 資訊管理學系研究所 === 96 === Voice over Internet Protocol, also called VoIP, Internet telephony and Broadband telephony is the routing of voice conversations over the Internet or through any other IP-based network. With the increasing of network bandwidth and progress of the network technology, the application of the VoIP is more and more general. A lot of colleges use their own VoIP system to communicate with the inside and outside. The government also request VSP (Voice Service Provider) to supply the functionality of emergency calls. The architecture of emergency call, suggested by the IETF ECRIT, transfers the location of users to LoST (Location-to-Service Translation) Server after users making an emergency call, and then the system will find out the most appropriate PSAP (Public Safety Answering Point) for the user. Each PSAP is responsible for its own service boundaries and the street addresses that it contains. For emergency calling, there are clear jurisdictional responsibilities for service regions. Because PSAPs have not be set up widely yet, we propose DECAP (DNS-SD based Emergency Call Access Point) for emergency calls over network to solve the problem of making emergency call in the campus. When the users want to make the emergency call, they just need to click the emergency call button on the DECAP UA. The system will query DNS for the information of emergency call service to find the most appropriate SIP Proxy and redirect the emergency call to the responsible police station by the PSTN Gateway in the college. We implement DECAP UA with PJSIP stack and DNS-SD SDK, and furthermore we provide the experimental results of delay time of dialing emergency call.