1 / 14

Emergency services for SIP

Emergency services for SIP. Henning Schulzrinne. Emergency services. Two types of emergency services: emergency calls ("911", "112") emergency notification ("inverse 911") emergency calls are hard: PSTN gateway dialing 911 may be located anywhere, far away from IP phone

ovidio
Download Presentation

Emergency services for SIP

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Emergency services for SIP Henning Schulzrinne

  2. Emergency services • Two types of emergency services: • emergency calls ("911", "112") • emergency notification ("inverse 911") • emergency calls are hard: • PSTN gateway dialing 911 may be located anywhere, far away from IP phone • VPNs  IP address may not reveal network location

  3. Emergency services • More than just replicating PSTN: • multimedia • video monitoring of accident scene or victim • video instruction in first aid • better than TTY for hearing-impaired • transmit biometric data • Easier to create multiple backup PSAPs

  4. PSTN emergency calling • Basic 911: call number, get routed to one Public Safety Answering Point (PSAP) • since 1968 in the United States • 93% of population covered by 911 • Enhanced 911: • route based on CLID (cannot be suppressed) • provide user location • started in 1970s, now 95% • see Bellcore SR4163 for details • see 47 USC 251 for legal mandate

  5. Wireless emergency calling • FCC Phase I: caller ID, cell site • FCC Phase II mandates user location: • Handset-based: • 50 meters for 67 percent of calls • 150 meters for 95 percent of calls • Network-based: • 100 meters for 67 percent of calls • 300 meters for 95 percent of calls

  6. VoIP emergency calls • Work for both "legacy" PSAPs and IP-based PSAPs • Define "sos" universal emergency address • find location of phone based on • street address  geocoding  long/lat, or • mobile: longitude, latitude • find appropriate jurisdiction and PSAP • use national database: long/lat  PSAP • find ESR (routing number)  call appears like 911 call • convey location to PSAP

  7. Emergency identifier • Requirements: • dialable from all SIP devices • universally recognized • note: SOS  "save our souls"! • not quite unassigned – consider 112@ and 911@? • Also allow "sos.fire" and others for specialized emergency services • Use sip:sos@home-domain to make handling predictable • intermediate proxies may deflect

  8. Routing emergency calls 302 Moved Contact: sip:sos@psap.leonia.nj.us Contact: tel:+1-201-911-1234 EPAD REGISTER sip:sos Location: 07605 INVITE sip:sos Location: 07605 SIP proxy INVITE sip:sos Location: 07605 INVITE sip:sos@psap.leonia.nj.us Location: 07605

  9. Where is the phone? • Regular GPS doesn't work well • doesn't work indoors • long time to first fix: 30"-15' • assisted GPS (A-GPS) • HDTV-based • Landline and 802.11 phones: • LAN jack tracing via traceroute, ARP, Cisco Discovery Protocol (CDP) and SNMP vLAN tables • 802.11 field strength triangulation (e.g., Microsoft, VTT) • hardware identification: • IR/RF tags • user data entry

  10. "Bergen County" 400 Broad Avenue Leonia, NJ Leonia "sos" A@ B@ C@ Alice ISDN B "911" Fort Lee ISDN D SS7 ISUP Bob RTP SIP call setup UDP audio (IP or circuit) IP SIP registration Bergen County analog phone IP phone 911 deployment SIP 0 1 0 c1.leonia.us IP UDP, TCP IP c2.leonia.us c1.fortlee.us IP 0 1 0

  11. Open issues • What needs to be standardized? • Are there any other UA behaviors? • prevent accidental disconnect • bypass carrier authentication • e.g., 3G requirement of REGISTER before calls? • Myth: During PSTN 911 calls, certain features (three-way calls, hang-up) are unavailable • true only for Basic 911

  12. Emergency notification • notify public officials and citizens of emergencies: • "tornado coming" • "fugitive alert" • current systems are typically single-mode (fax, telex, phone, TV, loudspeaker) • don't scale well • very limited information content • don't reach citizens outside calling area • people at work • hard to authenticate

  13. SIP-based emergency notification • SIP has scalable event notification feature • use for hierarchical notification reflecting civil lines of authority • use XML/WSDL message bodies to semantically describe emergency: • location • type of emergency • instructions • ... • allow automated reaction: • routing to legacy systems (pagers, police radios) • translation

  14. Emergency notification

More Related