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911 Background. Traditional 911 ~6,000 PSAPs in the US Selective routers route calls to correct PSAP Operated by carriers Relies on DB of fixed subscriber addresses Calling number (ANI) “pulsed” over CAMA trunk 1970s technology Number resolved to address (ALI) through geo-DB (MSAG) - PowerPoint PPT Presentation
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911 Background
Traditional 911• ~6,000 PSAPs in the US• Selective routers route calls to correct PSAP
– Operated by carriers
– Relies on DB of fixed subscriber addresses
• Calling number (ANI) “pulsed” over CAMA trunk– 1970s technology
• Number resolved to address (ALI) through geo-DB (MSAG)• PSAPs under pressure for years to support cellular E-911
Internet 911• 911 has been a thorn in the side of VoIP• FCC 911 mandate
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What Makes NG911 Hard
German Tourist
Taiwanese VSP
ISP=T-Mobile
Germany
PSAP
Rhode Island
•Mobility•ISP≠VSP•Not just “9-1-1”•Closed, proprietary legacy systems
emergency = “1-1-2”
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NG911
NG911 Project• Goal: deploy proof-of-concept IP-enabled PSAPs• $1.3 million dollar, two-year project funded by NTIA, the
States of Texas and Virginia 911 offices, Cisco and Nortel• National Emergency Numbering Association (NENA)
participation
Goal of NG911 is, not only to solve VoIP 911, but to do better!
• Higher resilience• Faster call setup• Testability• Internationality
• Multimedia support• Open standards and COTS• Cheaper
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Components of Emergency Calling
Contact well-known emergency number or ID
Route call to location-appropriate PSAP
Deliver precise location to PSAP for dispatch
Now Transition All IP
112911
112911
dial 112, 911urn:service:sos
selectiverouter
VPC DNS, LUMP
number location(ALI)
in-band key location
in-band
NENA I2 NENA I3
Establish caller locationfixed fixed or
infrastructure discovers
Client or proxy learns (e.g. GPS, CDP, LLDP-MED, DHCP)
This slide adapted from a slide of Henning Schulzrinne (Columbia University)
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Sample NG911 Call-flow
Taiwanese VSP
ISP
PSAP
Rhode Island
<location> (e.g. via DHCP)
INVITE urn:service:sosTo: urn:service:sos
<location>
mapping
INVITE sip:[email protected]: urn:service:sos
<location>
15
36
1-1-224
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PSAP Interface
This slide complements of Henning Schulzrinne (Columbia University)
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Bryan, TX PSAP
NG911Workstation
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For More Information
ECRIT (Emergency Contact Resolution with Internet Technologies) WG
• http://www.ietf.org/html.charters/ecrit-charter.html • Standardizing:
–location conveyance (with SIPPING & GEOPRIV)–emergency call identification–mapping geo and civic caller locations to PSAP–discovery of local and visited emergency dial string
NG911 Project• http://ng911.tamu.edu/