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NENA Next Generation 9-1-1 Architecture. Brian Rosen Senior Director, NeuStar Chair, NENA Long Term Definition WG. Background. NENA = North American Emergency Number Association Sets standards (among many other things) for emergency calls in U.S./Canada Next Generation 9-1-1 project
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NENA Next Generation 9-1-1 Architecture Brian Rosen Senior Director, NeuStar Chair, NENA Long Term Definition WG
Background • NENA = North American Emergency Number Association • Sets standards (among many other things) for emergency calls in U.S./Canada • Next Generation 9-1-1 project • Complete overhaul of the entire 9-1-1 system • Based on IP • Includes changes to processes, funding, training, etc, etc • The initial version of the technical standards part is known as “i3”
i3 is based on IETF Emergency Call Mechanisms • Endpoint (phone) “determines” its location by measurement (e.g. GPS) or from the access network via a “Location Configuration Protocol” • Endpoint “maps” the location to the URI of the PSAP with a new protocol, LoST • Endpoint learns LOCAL dialstring (9-1-1, 1-1-2) from LoST • Endpoint recognizes emergency call dialstring when dialed • Call is marked with service urn (urn:service:sos) • Call is sent to PSAP with mapped URI • Location is “conveyed” with the call • Call arrives at PSAP with location and call back info • Works for all media (voice, video, text, IM, …)
Location Determination • How location is actually figured out • Measurement (GPS) or wiretrace or manual configuration • Can be done by the endpoint or the access network • Can be civic (street address) or geo (lat/lon/altitude)
Location Configuration Protocols • How the access network provides location • Exchange an identifier of some kind, implicitly (e.g. what port on the switch) or explicitly (e.g. MAC address, IP address) for location • Location can be civic or geo • Current discussion on whether it can be a reference (e.g. URI) which must be dereferenced by some other protocol, or must be a value • DHCP is an example LCP • There is a “Layer 7” LCP in development • LLDP-MED is another example of an LCP
Marking an Emergency Call • Single global standard to denote an emergency call (does not rely on local dialstrings) • Uses a newly defined Service urn • Local dialstring is detected, and call is then marked with the service urn • Single number countries (9-1-1) use urn:service:sos • Number-per-service countries (1-1-6=police) use e.g. urn:service:sos.police • Extends to commercial location based routing, e.g. urn:service:restaurant.pizza.pizzahut) • Normally endpoint does dialstring to service URN translation, network can do it
Routing Emergency Calls • Location to Service Translation = LoST • Service URN + Location in, URI out • A “Mapping” function • Accepts civic/geo and service urn, returns URI, e.g. SIP and/or XMPP URI of where to route the call • Normal (SIP) routing of that URI • LoST is global, distributed, and replicated • Normally endpoint maps, network can do it • LoST will also supply the dialstring(s) for a location • LoST will also validate a civic location
Back to NENA i3 • All calls answered as IP calls at PSAP • Implies gateways between older TDM switches and PSAPs • All calls routed with LoST • Implies TN to location lookup prior to routing • All calls arrive at PSAP with location and call back address (can be URI or e.164)
Emergency Services IP Network • An IP network FOR ALL OF PUBLIC SAFETY, not just 9-1-1 • A regular routed IP network • DOES have (firewalled) connections to the Internet • Conceived as LOCAL networks (e.g. County level) interconnected with neighbors, perhaps a backbone for efficiency • Most local carriers will have private connections to the local ESInet • Option of using the Internet to introduce calls
Multi-Stage Routing • Emergency Services Routing Proxies at edge of ESInet onward route calls to PSAP • Uses LoST with authentication • User LoST query may return URI of ESRP • ESRP will foreward to PSAP • Could have more than one level of ESRP
More Data will be accepted • Additional Information about the call • Includes carrier contact info, subscriber class of service, etc • Call marked with URI of a datastructure to be retrieved by the PSAP • Also used for pointer to telematics data • Additional Information about the caller • Refers to the person, independent of home/office/mobile telephone • Could be medical info, “in emergency, please contact”, …) • Also a URI (anonymous), supplied by subscriber to carrier • Additional Information about the location • Comes from LoST • Two calls from same location will have same info, regardless of caller or carrier • Could be floor plans, hazardous materials, surveillance video, …
i3 PSAPs will be multimedia • Voice, Video, Text • Will support a variety of codecs (but not all of them, carriers don’t decide) • Will support both IM and interactive (character at a time codecs) • Full Offer/Answer negotiation • Will use codec choice to automatically engage relay operators if needed • Will use Language preference info to route calls to appropriate call takers, and automatically engage interpreters
3rd Party Calls • Used when user contacts a call center first • Text/Video/IP Relay • Telematics (OnStar) • Central Alarm Monitoring • Authorized 3rd parties can directly introduce calls, routed by location of user, with all 3 parties conferenced at the PSAP
PSAPs use LoST to route to responders • A PSAP will make LoST dips with caller’s location to determine the responding police, fire, ems, … services • A different service urn • Requires authentication • Same underlying database • This replaces the “ESN” of the current system
Notes to endpoint vendors • Read –phonebcp (will be draft-ietf-ecrit-phonebcp-00) • Implement ALL OF a short list of LCPs • Map location to PSAP URI and cache it • Recognize local (and maybe home) dialstrings as emergency calls • Mark emergency calls with service URN • Try to update location and LoST mapping at call time, use cached values if needed • Several other SIP things to support PSAP operations on calls • Support manual override of determined location, but make it possible, not easy to use
Notes to Access Network Providers • Need to choose one of the LCPs the phones will implement and deploy it • The only way to choose something not on the –phonebcp list is to force every endpoint to do something else • But watch out for Ethernet connected phones behind a router/switch with an uplink to your network; you may not be able to control them • Probably will be asked to supply a hint to a local LoST service • Validate (use LoST) civic locations when you put them in your location server
Notes to Communications (e.g. VoIP) Carriers • Prepare to route marked emergency calls to PSAP/ESRP • Prioritize marked emergency calls in softswitches • Deploy connections to local ESInets • Add the “Info about the call” URI with your contact data, etc. • Support Interactive Text & Video codecs all the way through the system for the disabled