ServiceMobility-fieldisbeingusedforcreatingstaticcontents服務(wù)流動(dòng)場被用于創(chuàng)建靜態(tài)的內(nèi)容

ServiceMobilityHenningSchulzrinne(withStefanBerger,JonathanLennox,XiaotaoWu)ColumbiaUniversity

SIP2003–January2003Paris,FranceOverviewMobility–morethancellphonesComponentsofservicemobilityconfigurationandsynchronizationdiscoveryLocation-basedservicesdetermininglocationsforSIPsystemscallroutingandpresenceservicesEndsystemservicecreationWorkinprogresswithinColumbiaIRTlabMobilitymodesTerminalmobilitymultiplenetworkattachmentpoints,sameidentifier

IPmobilityorSIPregistration&re-INVITEUsermobilitymultipleusers,sameidentifierSIPregistrationwithmultipleContact’sSessionmobilitymoveon-goingsessiontonewterminal(s)ServicemobilitykeepsameserviceswhenmovingMobileservicescreateservicesondeviceitselfSessionmobilityWalkintooffice,switchfromcellphonetodeskphonecalltransferproblem

REFERrelatedproblem:splitsessionacrossenddevicese.g.,walldisplay+deskphone+PCforcollaborativeapplicationassumedevices(orstand-ins)areSIP-enabledthird-partycallcontrolSessionmobilityvia3PCCINVITEspeakerphonem=audioc=pc42INVITEdisplaym=videoc=pc42INVITEdisplaym=videom=audioHowtofindservices?Twocomplementarydevelopments:smallerdevicescarriedonuserinsteadofstationarydevicesdevicesthatcanbetime-sharedlargeplasmadisplaysprojectorhi-rescamerasecho-cancelingspeakersystemswide-areanetworkaccessNeedtodiscoverservicesinlocalenvironmentSLP(ServiceLocationProtocol)allowsqueryingforservices“findallcolordisplayswithatleastXGAresolution〞SLPinmulticastmodeSLPinDAmodeNeedtodiscoverservicesbeforegettingtoenvironment“isthereacamerainthemeetingroom?〞SLPextension:findremoteDAviaDNSSRVServicemobilitySameservices,independentofdeviceandnetworkuseduseraddressbookspeeddialentriesSIPconfigurationnetworkpreferences(carrier)callhandlingalreadyhandledbyCPL,sip-cgi,servlets,…inhomeserverneedremoteupdatecapabilitySIPPUBLISHInmobilenetworks,providedbyGSMSIM(difficulttomovetodifferentdevices)HLRindomaindomainNeedsmall,portabletokenforidentificationtemporarydevicemaynotbecompletelytrustworthye.g.,airportpayphoneone-timepasswords(OTP)usedaskeyintodatabase(challenge-response)protocolunclearSIP?LDAP?ServicemobilityModes:synchronizationgoodifintermittentconnectivitySync-ML?XPath-basedsystemunderdevelopmentcentraldatabaseworksonlyifpermanentlyconnectedSIPconfiguration:getnotifiedifglobalordeviceconfigurationchanges(e.g.,securityupdate,newendsystemservices)retrievalviaHTTPorsimilar,notSIPpartialorfullupdatesrelatedtoInternetmediaguideproblemLocationsGeographiclocationlatitude,longitude,altitude,velocity,headingCivillocation(≠postallocation!)streetaddress,citysomecountriesareabitdifficult…Categoricaloffice,library,theater,hospital,…Behavioral“publiclocation,don'texpectprivacy〞“silenceisencouraged,don'tringthephone〞DetermininglocationsSIPentitiesareoftenfarawayfromphysicaluserorhiscurrentnetwork(intentionally)Formanydevices,can’taffordhardwaretodeterminelocationdifferentprecisionrequirements:“inFayetteCounty〞(withindrivingdistanceofserviceorperson)“oncampus〞“inroom815〞“incorner,talkingtoBob〞GPSdoesn’tworkindoors,butAssistedGPS(A-GPS)mayUselocationbeacons:BlueTooth,802.11maynotoffernetworkconnectivityseeour7DSproject:offerlocalcontent+locationPhysicallyclosebynetworkentities:DHCP(samebroadcastdomain)PPP(tailcircuit)NotalwaystruewithVPNs,butendsystemknowsthatit’susingaVPNDHCPforlocationsProposal:DHCPextensionsforgeographicandcivillocationgeographic:resolution(bits),long/lat,altitude(metersorfloors)civil:what:endsystem,switchorDHCPserverhierarchicalsubdivisions,fromcountrytostreet,landmarkname,occupantAlso,someLANswitchesbroadcastportandswitchidentificationCDPforCisco,EDPforExtremeNetworksCanalsousebacktrackingviaSNMPswitchtableslocallyimplementedforemergencyservices(Perlsip-cgiscript)Location-basedservicesServices:Location-awarecallrouting“donotforwardcalliftimeatcalleelocationis[11pm,8am]〞“onlyforwardtime-for-lunchifdestinationisoncampus〞“contactnearestemergencycallcenter〞“donotringphoneifI’minatheater〞“sendtonearestbranch〞Location-basedeventssubscribetolocations,notpeople“Alicehasenteredthemeetingroom〞subscribermaybedeviceinroomourlabstereochangesCDsforeachpersonthatenterstheroomPerson+locationeventsWe’reimplementingSIP,caller-preferencesandCPLextensionsfortheseservicesSIPextensionsforlocation-basedservicesLocationinformationishighlysensitivecompletetrackingofpersonstalkersandburglarswouldkillforthisinformationIETFGEOPRIVprinciple:“target〞cancontroldisseminationoflocationinformationrestricttimeofday,information(location,heading,velocity)resolution,numberoftimesqueried,destination,retention,…“AliceisintimezoneMET〞maybeokforstrangers,but“Aliceisat41.872833N,087.624417W,headingNEat45mph〞isnotGEOPRIVstilldefiningapplicationscenariosinmanycases,easiesttoincludelocationinformation“in-band〞withprotocol,asthisavoidsdelegatingauthorizationotherwise,needtogiveaccesskeytodatabasetorecipientweproposeaddingSIPLocationheaderfieldSIPserviceinterfacesCPLSIPCGISIPServlet@ECHOOFFIF%SIP_FROM%==GOTOBLOCKGOTOEXIT:BLOCKechoSIP/2.0486Busy:EXIT<?xmlversion="1.0"?><!DOCTYPEcplPUBLIC"-//IETF//DTDRFCxxxxCPL1.0//EN""cpl.dtd"><cpl><incoming><address-switchfield="origin"subfield="user"><addressis="anonymous"><rejectstatus="reject"reason="Idon'tacceptanonymouscalls"/></address></address-switch></incoming></cpl>publicbooleandoInvite(SipRequestreq){SipResponseres=req.createResponse();res.setStatus(486);res.send();returntrue;}#!/usr/bin/envperl-w#Rejectmessageswhose'From:'matches'sip:hgs@'by#respondingwith486Busy,redirecttheotherstovoicemailprint"SIP/2.0100Wait\n\n";if(defined$ENV{SIP_FROM}&&$ENV{SIP_FROM}=~"sip:hgs@"){print"SIP/2.0486Don'tdisturb,Iamworking\n\n";}else{print"SIP/2.0302Redirect\n";print"Contact:sip:xiaotaow\@\n\n";}EndsystemservicesTechniquesfornetworkservicesarenotgoodforendsystemservices:differentservicecreatorsendsystemrequirementsCurrentlyavailable:XML-basedscreeninteraction(Cisco)Javaapplets(Pingtel,3Gphones)NetworkServicesv.s.

EndSystemServicesNetworkServicesv.s.

EndSystemServicesNetworkservicesEndsystemservicesDeveloperexperienceddevelopersnon-programmersMediaandotherendsystemapplicationsindirectcontrolviaSDPdirectcontrolUserinteractionindirectdirectEndsystemservicelanguagesSimpleandeasytounderstandbynon-programmersPlatformneutralExpressuserinteractionsControlmediaandotherendsystemapplicationsExtensibletoaccommodatenewservicesRestrictedtocertainclassofservices,notnecessarilyTuring-completeEndpointServiceMarkupLanguage(ESML)XMLbasedlanguagePlatformandunderlyingprogramminglanguageneutralReadablebynon-programmersDefinedasanXMLschemaDerivationofnewtypesPre-definedtypesTree-likestructureUsepackagestogroupeventsandactionsESMLexample<esmlname="online_call"require="genericpresenceui"><notificationstatus="online"priority="0.5"><address-switchfield="origin"><addressis=""><call/><alertsound=“foo.au"text="Calling"/></address></address-switch></notifying></esml>Deviceagentx10vcrSIPuseragent