LUMP: Location-to-URL mapping draft-schulzrinne-ecrit-lump Henning Schulzrinne Columbia University Dept. of Computer Science ECRIT interim meeting - Washington, DC - Feb. 2006

LUMP: Mapping service URNs + locations to URLs Common problem: {geo or civic location, service}  set of URLs e.g., {Broadway/NY, “911”}  fire@psap.nyc.gov also applies to anything from AAA to pizza delivery Service providers don’t trust each other (fully) e.g., who gets to include Jerusalem in its map service may depend which warlord you belong to  can’t wait for UN (or ICANN) to create global emergency services database Suggested approach: new distributed mapping protocol LUMP: location-to-URL mapping protocol uses SOAP, but special service URLs ECRIT interim meeting - Washington, DC - Feb. 2006

LUMP: Location-to-URL Mapping VSP1 cluster serving VSP1 replicate root information cluster serves VSP2 123 Broad Ave Leonia Bergen County NJ US root nodes NJ US NY US sip:psap@leonianj.gov search referral Bergen County NJ US Leonia NJ US ECRIT interim meeting - Washington, DC - Feb. 2006

LUMP architecture G G G G G T2 (.de) T3 T1 (.dk) (.us) tree guide T1: .us T2: .de broadcast (gossip) G resolver T2 (.de) seeker 313 Westview Leonia, NJ US T3 (.dk) T1 (.us) ECRIT interim meeting - Washington, DC - Feb. 2006 Leonia, NJ  sip:psap@leonianj.gov

ECRIT interim meeting - Washington, DC - Feb. 2006 Caching Generally, UA caches lookup results query: “I’m at (X,Y), what’s my PSAP?” answer: “Your PSAP is sip:psap@town.gov as long as you stay in polygon (X1,Y1; X2, Y2; …); this is valid for 12 hours” almost no impact of node mobility on query frequency same for civic: “as long as you stay on Main Street, your town” civic only relevant for nomadic users actual PSAP coverage area may be larger  just an optimization Almost always avoids query during emergency call MAY re-query during call load distribution via DNS given frequency of calls for one resolver, likely to be no DNS caching anyway Further optimization: query with timestamp (or etag) of last answer answer: “still the same, thanks for asking” ECRIT interim meeting - Washington, DC - Feb. 2006

ECRIT interim meeting - Washington, DC - Feb. 2006 Performance notes Use TCP (or TCP/TLS) for reliability Expect 1-2 queries/day/client Typical: >> 100 queries/second/server almost all rows will be cached in memory only about 6,000 rows one server  8,640,000 queries probably N+1 spared data center cost: $300/month/server  $0.0003/user/month (1Mq/day) ECRIT interim meeting - Washington, DC - Feb. 2006

Implementation status Prototype implementation includes referrals both geo and civic coordinates from draft WSDL (with minor fixes) Server Axis (Apache) SOAP server Postgres SQL geo database does polygon intersection Client Java servlet (web page) Tcl (for our SIP client) ECRIT interim meeting - Washington, DC - Feb. 2006