Multimedia SIP Sessions in a Mobile Heterogeneous Access EnvironmentOutlineMotivation (1)Motivation (2)Slide 5Slide 6SIP BackgroundSIP Background: ComponentsWhy SIP Mobility ?Types of SIP mobilitySIP Mobility Basic FlowsHandoff Delay Analysis (SIP-Mobility)Heterogeneous Access for Services in a LAN (SIP and Mobile IP approach)Heterogeneous Access for SIP SessionsTechnical Issues (1)Technical Issues (2)Slide 17Experimental Setup and ResultsConclusionsMultimedia SIP Sessions in a Mobile Heterogeneous Access EnvironmentAshutosh Dutta, Yibei Ling, Wai Chen, Jasmine ChennikaraTelcordia TechnologiesOnur Altıntaş Toyota InfoTechnology Center, USAHenning Schulzrinne Columbia University2OutlineSIP based mobilityHeterogeneous Access ArchitectureIssues related to SIP-based sessionsSIP sessions for Heterogeneous NetworksExperimental Setup and ResultsConclusions3Motivation (1)Objective: Analyze and experiment with a carrier-independent end-to-end Mobility Solution for scalable wireless Internet Roaming involving PAN, LAN and WAN4Motivation (2)Wireless Internet Roaming is becoming a norm rather than an exceptionSIP is gaining momentum as a signaling mechanism for multimedia sessionsSIP provides an application layer multi-facet mobility solutionMany drawbacks associated with Mobile IP are taken care of–No dependence on HA based solutionMultiple Access Technologies (Bluetooth, 802.11x, CDMA, GPRS)–Provide an integration between PAN, LAN and WAN–Flexibility of selecting a particular interface based on type of applicationSmooth transition between heterogeneous access networks by providing a virtual soft-handover5WLAN NetworkAccessNetwork 2AccessNetwork 3CellularNetworkS1S2S3S4AccessNetworkAccessNetworkAccessNetworkCellularNetworkInternetDomain1Domain2PDAWebphoneMulti-mediaTerminalANAccessNetwork 1Wireless Internet Roaming in Heterogeneous Environment SIP UA SIP UA SIP UAPAN6Media TransportApplication DaemonKernelPhysical NetworkH.323SIPRTSPRSVP RTCPRTPTCP UDPIPv4, IPv6, IP MulticastPPP AAL3/4 AAL5 PPPSONET ATMEthernetCDMA 1XRTT/GPRSSignalingmedia encap(H.261. MPEG)ICMP IGMPSAP802.11bDNSLDAPMIPMIP-LRCIPSDPMIPv6MGCPIDMPIETF Multimedia Protocol StackDHCPPHeterogeneous Access7SIP BackgroundSIP allows two or more participants to establish a session including multiple media streams–audio, video, distributed games, shared applications, white boards, or any other Internet-based communication mechanismStandardized by the IETF RFC 2543Is being implemented by several vendors, primarily for Internet telephony–e.g. Microsoft XP operating system includes SIP as part of its built-in protocol stack Recently being extended to provide presence, instant messaging and event notificationEndpoints addressed by SIP URLs –sip:[email protected] Background: ComponentsSIP serverRegistrarProxyLocationDatabaseRedirectProxySIP User Agent ClientHostSIP User Agent ClientSIP User Agent ServerHostSIP User Agent ServerUDP/5060 (Signaling)UDP/5060 (Signaling)RATWBVICCHATVNCRATWBVICCHATVNCaudiovideowhite boardtextdesktop sharingRTP/UDPRTCP9Why SIP Mobility ?SIP is an application layer signaling protocol:–it can keep mobility support independent of the underlying wireless technology and network layer elements;3GPP, 3GPP2, and MWIF have agreed upon SIP as the basis of the session management of the mobile Internet SIP will eventually be part of the mobile Internet so why not use its inherently present mobility support functionsSIP can provide personal mobility, terminal mobility, session mobility and service mobilityNo requirement to modify (or add) capabilities to existing terminal’s operating system10SIP provides variety of mobility techniques–Personal MobilityAllows users to be reachable in multiple locations using a unique URI–Service Mobility Allows users to maintain access to their services while moving between service providers–Session MobilityAllows a user to maintain a media session while changing between terminals– Mid-session (terminal) mobilityAllows a user to maintain a session while moving (support for real-time streaming applications for mobiles)Types of SIP mobility11SIP Mobility Basic FlowsCH MHMH (new location)SIP SignalingRTP Media streamMH moves during sessionRe-registerRe-INVITE with new Contact addressSIP signaling and RTP/UDP session remains intactSIP serverRegister12Handoff Delay Analysis (SIP-Mobility)CHMH (IP0)SIP SignalingRTP SessionBase StationMH (IP1) MH movesBeaconDHCP/PPP ServerDiscover/RequestOffer/IP addressBinds L2L3Configuration TimeRe-InviteRTP SessionMedia RedirectionBeacon IntervalBeaconL2 = Layer 2L3 = Layer 313Heterogeneous Access for Services in a LAN (SIP and Mobile IP approach) CDMA802.11x WaveLanDHCPDHCPInternetSubnet S0Subnet S1IPS01IPS02IPS11 IPS12CH/Media ServerSIPServerSIPServerSIPUASIPUAPPPServerPPPServerBluetoothCDMABluetoothVisited Network AVisited Network BHome NetworkIntra-NetHomeAgentRouter/Foreign agentRouter/Foreign AgentSIPUAIntra-Subnet MobilityIntra-Subnet MobilityInter -Subnet MobilityInter -Subnet MobilityIPS03IPS13802.11x14Heterogeneous Access for SIP SessionsCDMA/GPRSCDMA/GPRSMHCellularAccessNetworkWLANAccessNetworkCHLocalSIPServerDHCP/PPPDHCP/PPPDHCPDHCPIPA1IPA2IPB1IPB2LocalSIPServerIPchCoreNetworkCoreNetworkHomeSIPServerCoreNetwork802.11x802.11xPublic InternetPublic SIPServerRouterRouterAAA15Technical Issues (1)Movement during session setup –With direct signaling Retransmissions after timeout–With proxy serverRedirects to the right IP addressSIP sessions with NAT: IP address MH uses to invite CH will not reach MH (e.g. 3G network may be an Intranet)–Use of Application Layer Gateway–STUN (Simple Traversal of UDP through NAT)User Agent with Multiple IP addresses detection–SNR based–Policy based–can be application specific (e.g. audio use CDMA, video use WLAN)16Technical Issues (2)Multiple IP registrations–Register the active IP address –Forking proxyDe-Register with the previous SIP server once the active interface changes–Public SIP servers can be used with proper security associationProper Triggering Mechanism to change active interface–Channel change, –QoS of traffic, –server based, –L3 router solicitation17DNSDHCPDHCP DHCP“Outdoor”sun90sun80.21Domain:SN1Domain:SN2Domain:SN3cisco80cisco90CompanyIntranetInternetIGWHUBPrivate Subnet 1Private Subnet 2Private Subnet