SDO Emergency Services Coordination Workshop (ESW06) 1 A Location-to-Service Translation Protocol (LoST) & Mapping Protocol Architecture Ted Hardie Andrew Newton Henning Schulzrinne Hannes Tschofenig

SDO Emergency Services Coordination Workshop (ESW06) 2 Overview LoST is a simple XML-based query and response protocol running on top of HTTP –either “naked” HTTP or SOAP Main Purpose: Return URIs for given location information and service identifier –i.e., service URN + location  URIs Status: Work in progress –Expected WGLC in Nov. 2006

SDO Emergency Services Coordination Workshop (ESW06) 3 Finding the correct PSAP Which PSAP should the e-call go to? –Usually to the PSAP that serves the geographic area –Sometimes to a backup PSAP –If no location, then ‘default’ PSAP

SDO Emergency Services Coordination Workshop (ESW06) 4 LoST Functionality Satisfies the requirements (draft-ietf-ecrit-requirements) for mapping protocols Civic as well as geospatial queries –civic address validation Recursive and iterative resolution Fully distributed and hierarchical deployment –can be split by any geographic or civic boundary –same civic region can span multiple LoST servers Indicates errors in civic location data  debugging –but provides best-effort resolution Supports overlapping service regions

SDO Emergency Services Coordination Workshop (ESW06) 5 LoST Properties Minimizes round trips: –caching individual mappings –returns coverage regions (“hinting”) civic (“all of C=US, A1=NY”) or geo (polygon) Facilitates reuse of Transport Layer Security (TLS) Returns emergency service numbers for a region Query for supported Service URN types

SDO Emergency Services Coordination Workshop (ESW06) 6 Protocol request (mapping) <findServiceByLocation xmlns="urn:ietf:params:xml:ns:lost1 " validate="false" operation="recursive"> US New York Broadway Suite urn:service:sos.police details likely to change

SDO Emergency Services Coordination Workshop (ESW06) 7 Protocol response (mapping) New York City Police Department unknown US New York 911

SDO Emergency Services Coordination Workshop (ESW06) 8 Validation Determine if civic location is (partially) valid Returns XML tag names of components: –validated and used for mapping –no attempt to validate (and not used) e.g., house number –known to be invalid Return (default) PSAP based on validated elements May return list of guesses for correct addresses, if requested

SDO Emergency Services Coordination Workshop (ESW06) 9 Geo support Which geo types should be supported? –Point (3D) –Polygon?  may yield ambiguous answers –more complicated shapes? Current proposal –always include 3D-point –may include other shapes

SDO Emergency Services Coordination Workshop (ESW06) 10 LoST: Location-to-URL Mapping cluster serves VSP 2 NY US NJ US Bergen County NJ US 123 Broad Ave Leonia Bergen County NJ US cluster serving VSP 1 replicate root information search referral root nodes Leonia NJ US VSP 1 LoST

SDO Emergency Services Coordination Workshop (ESW06) 11 LoST Architecture T1 (.us) T2 (.de) T3 (.dk) G G G G G broadcast (gossip) T1:.us T2:.de resolver seeker 313 Westview Leonia, NJ US Leonia, NJ  tree guide

SDO Emergency Services Coordination Workshop (ESW06) 12 Conclusion Mapping is core component of emergency calling problem LoST fully international and distributed –tries to avoid “who runs the root” problem optimized for efficient use in mobile end systems

SDO Emergency Services Coordination Workshop (ESW06) 13 References and Contact Info IETF ECRIT Working Group LoST draft Mapping architecture draft: Prototype implementation work in progress (see demo) –First interoperability tests planned for early 2006 / beginning 2007.