Providing Emergency Services in Internet Telephony Henning Schulzrinne

Providing Emergency Services in Internet Telephony Henning Schulzrinne and Knarig Arabshian Department of Computer Science Columbia University {hgs, knarig}@cs. columbia. edu

Overview IP telephony (SIP) n E-911 service n Emergency calling using SIP n Emergency notification systems n SIP based notification n Conclusions n

IP telephony (SIP) • Address based on email (alice@home. com) 1. Outgoing proxy 2. DNS SRV for SIP home. com pc 1. home. com 129. 59. 140 3. INVITE alice@home. com 4. INVITE alice@m 2. home. com (proxy mode) office. com (1) Bob Alice (3) (4) Columbia. edu Cisco. com pc 1. home. com m 2. home. com

E-911 Service Four components needed 1) Universal number such as 911 1 -212 -9397063 613 CEPSR, Columbia Univ 2) Call routing to an emergency response center-PSAP 3) Caller Identification Who is calling? caller-id to avoid prank call 4) Caller Location Where is he calling from? Address for speedy response

E-911 Service How it works? Selective routing database Prefix Emergency Service Number SRDB 212939 xxxx 2345 Emergency Service Number Primary PSAP 2129119345 2345 Secondary PSAP 2129119456 2129119345 Central office 1 -212 -9397063 2129397063 613 CEPSR, 120 th st Broadway Telco and Amsterdam Ave DB

Emergency Call using SIP (Legacy PSAP sees the gateway) SIP-PSTN gateway (switch room) ESR DB PSAP SRDB PSTN 939713 x Central office 2129397130 606 CEPSR IP network Sends fire-fighters to the switch room. 128. 59. 19. 61 (multimedia lab) Telco DB

Emergency Call using SIP (IP-enabled PSAP is aware of IP telephony) PSAP Outbound Proxy IP Network LAN Richer Communication Envorinment: video to instruct caller in first aid or use sign language, text -based messaging, etc. 128. 59. 19. 61 (multimedia lab)

Architecture for Internet Telephony Use local switch tables to get the address of the caller PSAP EPAD INVITE sip: sos@example. com SIP/2. 0 Location: Rm. 523, 123 Main Street Centerville, NY 302 Moved Temporarily Contact: tel: +1 -212 -911 -1234 Outbound Proxy INVITE sip: 1 -212 -911 -1234@gw-r-us. com Location: Rm. 523, 123 Main Street Centerville, NY

What are Emergency Notification Systems? n n n Allow government officials to notify a community of an emergency and precautionary measures that must be taken Different emergency situations and alert methods u Fire Alarms, Earthquake or chemical spills indicated by sirens, Notifying public of terrorist attacks via radio/TV broadcasting Emergency Alert System (EAS) u Controlled by the government and used for wide area emergency notification

SIP-based Emergency Notification Use SUBSCRIBE/NOTIFY methods n Clients will subscribe to servers for emergency notification n Servers will notify clients of particular emergency situation n

SUBSCRIBE sip: alerts@leonia. nj. us SIP/2. 0 Event: alert. mathaz From: sip: alice@example. com To: sip: alerts@leonia. nj. us CLIENT (SUBSCRIBER) SIP/2. 0 202 Accepted From: sip: alice@example. com Expires: 86400 NOTIFY sip: alerts@leonia. nj. us SIP/2. 0 Event: alert. mathaz To: sip: alice@example. com From: sip: alerts@leonia. nj. us fire wood 2 SERVER (NOTIFIER)

Alerting Hierarchy United States Federal Govt. Alabama Alaska New Jersey SUBSCRIBE Atlantic NJ State Govt. Wisconsin NOTIFY Bergen Wyoming

Benefits Device Neutrality n More Information and Automated Action n Lower resource consumption n Integration with current systems n Out-of-area notification n

Conclusion and Future Work IP telephony gives opportunity to enhance existing emergency services by creating more functional, robust and flexible systems n Future/Ongoing work includes: u Location resolution of caller and finding nearest PSAP u Building a demo of an emergency notification system using SOAP n