1

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

2

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”

3

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

4

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)

5

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:psap@prov.state.ri.usTo: urn:service:sos

<location>

15

36

1-1-224

6

PSAP Interface

This slide complements of Henning Schulzrinne (Columbia University)

7

Bryan, TX PSAP

NG911Workstation

8

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/