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

ECRIT interim meeting - Washington, DC - Feb LUMP: Mapping service URNs + locations to URLs Common problem: –{geo or civic location, service}  set of URLs –e.g., {Broadway/NY, “911”}  –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 LUMP: 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

ECRIT interim meeting - Washington, DC - Feb LUMP 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

ECRIT interim meeting - Washington, DC - Feb Caching Generally, UA caches lookup results –query: “I’m at (X,Y), what’s my PSAP?” –answer: “Your PSAP is as long as you stay in polygon (X 1,Y 1 ; X 2, Y 2 ; …); 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 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 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)