VoIP/NG E9-1-1 IP-based E9-1-1 Migratory & Long Term
Solutions – A Trial/Demo Update
Purpose of Project
• Conduct research in support of NENA’s Next Generation E9-1-1 initiative
• Conduct that research without endangering public safety
• Share the results of that research with the public safety community
Assumptions
• Existing circuit switched 9-1-1 network will be replaced with a new network (NG E9-1-1)
• PSAPs will have to be capable of handling calls via packet switched links
• Independent research can help us to get ready
Project Description• Extend prototype architecture into a campus
environment and working PSAPs• Conduct tests of IP enabled emergency
calling• Explore nomadic location services• Conduct long distance PSAP to PSAP
transfers• Prove the value to public safety community of
multimedia information data transfer
Project Description (continued)• Explore lower cost off-the-shelf call taking
equipment in Public Safety Answering Points,• Validate many of NENA’s requirements for the
IP-enabled Public Safety Answering Point of the future,
• Transfer knowledge to 9-1-1 community via presentations and workshops
• Total project value - $1.5 million
Partners• Columbia University, Texas A & M University,
and University of Virginia• Internet2• Texas and Virginia PSAPs • NENA• Texas and Virginia state 9-1-1 agencies• Cisco and Nortel• NTIA - grant funding
Project Overview
Columbia University Dr. Henning Shulzrinne• Internet Real-Time (IRT) labs
• Developed prototype• Continue development work• Participate in testing• Draft RFC’s
Project Overview (continued)
Texas A & M University Dr. Walt Magnussen• Internet2 Technology Evaluation Center (ITEC)
• Additional development• Coordinate field testing
• Facilitate workshops and project demonstrations
• Center for Distance Learning Research (CDLR) • Independent, outside evaluation of the project
Project Overview (continued)
University of Virginia • Coordinate testing of the remote PSAP
routing capabilities
Internet2 Consortium• Coordinate efforts of this project with other
Internet2 projects • Disseminate information to other Internet2
members.
Project Overview (continued)PSAPs
• Brazos County Emergency Communication District • City of College Station, Texas • Charlottesville, Albemarle, UVA Emergency
Communications Center
• Call takers will participate in testing and provide feedback for the evaluation portion of the project
Project Overview (continued)NENA
• Coordinate user requirements in the development of the project
• Coordinate information dissemination to the user community through white papers, workshops and seminars
Texas and Virginia 9-1-1 Agencies• Funding Support• Information Dissemination
Project Overview (continued)Cisco
• Provide hardware and software • Provide access to one of their E-911 gateway
solutions • Provide access to source code to Cisco equipment
and applicationsNortel Inc.
• Provide a SIP based switching platform • Provide wireless system with the ability to provide
location information about the Access Point being utilized for the connection
Progress to Date• Initial Formation of Project Team• Acquired NTIA matching grant funding• Development of network architecture• Establishment of lab environment at
Columbia University• Creation of preliminary PSAP call handling
equipment to receive native VoIP• Demonstration of call processing at the
National Press Club on May 26, 2005
Next steps
• Refine PSAP equipment configuration• Adding features and functionality• Improve reliability and diversity
• Develop method for location validation
• Address nomadic users
Lessons Learned
• VoIP can provide a strong foundation for PSAP call processing
• PSAP equipment can be based on non-proprietary VoIP equipment
• General location for routing can typically be determined by DNS
Components of emergency calling
Contact well-known number or
identifier
Route call to location-
appropriate PSAP
Deliver precise location to call taker
to dispatch emergency help
now transition all IP
112911
112911
dial 112, 911 signal sos@
selectiverouter
VPC DNS
phone number location(ALI lookup)
in-band key location
in-band
What makes VoIP 112/911 hard?
POTS PSTN-emulation VoIP end-to-end VoIP
(landline) phone number limited to limited area
landline phone number anywhere in US (cf. German 180)
no phone number or phone number anywhere around the world
regional carrier national or continent-wide carrier
enterprise “carrier” or anybody with a peer-to-peer device
voice provider = line provider (~ business relationship)
voice provider ≠ ISP voice provider ≠ ISP
national protocols and call routing
probably North America + EU
international protocols and routing
location = line location mostly residential or small business
stationary, nomadic, wireless
The core problem
VSP sees emergency callbut does not know caller location
ISP/IAP knows user locationbut does not handle call
More than pain…Multimedia from the caller
• video capture from cell phones• video for sign language• text messaging and real-time text for the deaf
Data delivery• caller data: floor plan, hazmat data, medical alerts• measurement data input: automobile crash data, EKGs, …
Delivering video to the caller• e.g., CPR training
Load balancing and redundancy• currently only limited secondary PSAP• VoIP can transfer overload calls anywhere
Location delivery• carry location with forwarded and transferred calls• multiple location objects (civic + geo)
Core long-term requirementsMedia-neutral
• voice (+TDD) first, IM and video laterWork in systems without a voice service provider
• many enterprises will provide their own local voice servicesAllow down-stream call data access
• as well as access to other “tertiary” data about the incidentGlobally deployable
• independent of national emergency number (9-1-1, 1-1-2, etc.)• respect jurisdictional boundaries – minimize need for cross-
jurisdictional coordination• allow usage even if equipment and service providers are not local
• travel, imported equipment, far-flung locationsTestable:
• verifiable civic addresses (“MSAG validation”)• call route validation
Secure and reliable
Three stages to VoIP 911
spec. available?
use 10-digit admin. number?
mobility callback
number to PSAP?
caller
location to PSAP?
PSAP
modification
ALI (DB)
modification
new services
I1 now allowed stationary no no no no none
I2 June 2005
no stationary
nomadic
yes yes no (8 or 10 digit)
update none
I3 2005 no stationary
nomadic
mobile
yes yes IP-enabled ALI not needed
MSAG replaced by DNS
location in-band
GNP
multimedia
international calls
I3: Location-based call routing – UA knows its location
GPS
48° 49' N 2° 29' E
INVITE sips:sos@
DHCP
outboundproxy server
48° 49' N 2° 29' E Paris fire department
Location, location, location
Location locate right PSAP & speed dispatchIn the PSTN, local 9-1-1 calls remain geographically
localIn VoIP, no such locality for VSPs
• most VSPs have close to national coverage
Thus, unlike landline and wireless, need location information from the very beginning
Unlike PSTN, voice service provider doesn’t have wire database information• VSP needs assistance from access provider (DSL, cable,
WiMax, 802.11, …)
Options for location delivery
L2: LLDP-MED (standardized version of CDP + location data)• periodic per-port broadcast of configuration
informationL3: DHCP for
• geospatial (RFC 3825)• civic (draft-ietf-geopriv-dhcp-civil)
L7: proposals for retrievals• by IP address• by MAC address• by identifier (conveyed by DHCP or PPP)
DHCP for locationsmodified dhcpd (ISC) to generate location informationuse MAC address backtracing to get location information
DHCPserver
458/17 Rm. 815458/18 Rm. 816
DHCP answer:sta=DC loc=Rm815lat=38.89868 long=77.03723
8:0:20:ab:d5:d
CDP + SNMP8:0:20:ab:d5:d 458/17
NG-911 prototype
Goal: build prototype VoIP SIP-based emergency calling system• including caller end system• call routing (DNS)• PSAP infrastructure
Use commodity components where possible
Test reliability and redundancy
Call routing
911112
sip: sos@domain 1w/location or w /out location
geo location
POTS/Wireless Network
IP Network
911
Envinsa Server
sip:psap @domain 2with location
GeoLynx Display
ALI Server
DHCP Server
DHCP InformMAC Address
Location Info
PSAP Info
HTTP SOAPgeo location
civil location
PSAP Info
DNS Querycivil location
DNS Server
geo locationcivil location
3PCC Controller
Location Info
IP Gateway
Local SIP Proxy
PSAP
TCP Socket Telephone Number
PSAP SIP Proxy
sip: psap@ domain 2with location
sip :rep@ domain 2with location
sip :psap @domain 1without location
Components
sipd SIP proxy server
database-backed DNS server
SIP phone
web server
SQL database for call routing
sipc SIP user agent
geo-coding, PSAP boundaries
GIS software for call location plottingNo endorsement implied – other components likely will work as well
SIPc client receives calls GeoLynx software displays caller location
Call taker setup
GeoLynx listens for commands from SIPc
GeoLynx displays location
Emergency call conferencing
INVITE
3rd partycall control
INVITE
INVITE
REFER
REFER
REFER
Conferenceserver
PSAP
Recorder
Firedepartment
HospitalPSAP brings all related parties into a conference call
INVITE
media info
INVITEmedia info
Caller
INVITE
Scaling
NENA: “estimated 200 million calls to 9-1-1 in the U.S. each year”
approximately 6.3 calls/second• if 3 minute call, about 1,200 concurrent calls
typical SIP proxy server (e.g., sipd) on 1 GHz PC can handle about 400 call arrivals/second
thus, unlikely to be server-bound
Current standardization efforts
NENA (National Emergency Number Association)• I2 and I3 architecture• requirements based on operational needs of PSAPs
ETSI OCG – EMTEL• exploratory – also emergency notification
NRIC• goals and long-term architecture
IETF:• individual and SIPPING drafts for identifier, call routing,
architecture• SIP and DNS usage• possibly new protocols for lookups• ECRIT WG for mapping part just getting started
Conclusion
Emergency calling services necessary condition for first-line wireline-replacement services
US: large numbers of PSAPs financially exhausted from Phase II wireless support• often 1970s technology – end of bailing wire
reached
Long-term opportunity for better services