The Internet Real-Time Laboratory (IRT) http://www.cs.columbia.edu/IRT Prof. Henning
The Internet Real-Time Laboratory (IRT) http://www.cs.columbia.edu/IRT Prof. Henning Schulzrinne Dept. of Computer Science Columbia University New York, NY June 2004 Networking research at Columbia University Columbia Networking Research Center spans Electrical Engineering & Computer Science Department 15 faculty one of the largest networking research groups in the US about 40 PhD students
spanning optical networks and wireless channels to operating systems, security and applications theory (performance analysis) to systems (software, protocols) Keren Bergman Andrew Campbell Ed Coffman Predrag Jelenkovic Angelos Keromytis Aurel Lazar Nick Maxemchuk Vishal Misra Jason Nieh Dan Rubenstein Henning Schulzrinne Xiaodong Wang Yechiam Yemini Laboratory overview Dept. of Computer Science: 33 faculty IRT lab:
1 post-doc 12 PhD students includes part-time students working at IBM, Lucent, Telcordia 2 MS GRAs visitors (Ericsson, Fujitsu, Mitsubishi, Nokia, U. Coimbra, U. Rome, NTT, ) China, Finland, Greece, India, Japan, Portugal, Spain, Sweden, US, Taiwan ~15 MS and undergraduate project students Laboratory support Equipment grants and student support Overall IRT lab goals
Reliable, flexible and programmable communication infrastructure for Internet-based collaboration applications Systematic evaluation by analysis and simulation Demonstrate capability via prototypes Contribute protocols to standardization Convert prototypes into products and open-source software Train students at all levels in current Internet research and engineering IRT research topics Internet telephony and multimedia
CINEMA VoIP/multimedia and collaboration system QoS measurements network application reliability APIs for SIP IM and presence systems ubiquitous computing using SIP emergency services (911) SIP security non-PKI-based assertions service creation languages CPL LESS
Mobile and wireless systems 802.11 handoff acceleration 802.11 VoIP performance improvements personal, service and session mobility Peer-to-peer messaging 7DSDS Service and event discovery (GloServ) Generic signaling protocols (GIMPS) for QoS, NAT/FW,
Autonomic computing service discovery mSLP automated server pooling DotSlash Graduated PhD students Internet telephony services, GSM interoperation (J. Lennox) QoS and reliability measurements (W. Jiang) Federated CDNs (L. Amini) Pricing for QoS, LDAP performance (X. Wang) Multicast QoS fairness & signaling (P. Mendes)
Internet telephony topics (J. Rosenberg) Mobile peer-to-peer systems (M. Papadopouli) Scalable resource reservation (P. Pan) Multimedia systems problems Old problems and approaches: efficient codecs ubiquitous reachability audio/video synchronization network-layer mobility quality-of-service APIs and middleware
New problems: controlled reachability spam cell phone ringing in lecture service availability information privacy service & personal mobility service creation by non-experts CINEMA components Cisco 7960 MySQL
sipconf rtspd conferencing server (MCU) RTSP media server user database LDAP server sipd proxy/redirect server RTSP unified messaging server Pingtel Nortel Meridian PBX
4 7134 => bob SIP emergency calling GPS INVITE sips:[email protected] 48 49' N 2 29' E outbound proxy server DHCP 48 49' N 2 29' E Paris fire department SIP for ubiquitous computing Focus on inter-domain, scalable systems Components:
context-aware communications context-aware service and event discovery location-based services global-scale event notification service creation by end users terminal, personal, session and service mobility Context-aware communication context = the interrelated conditions in which something exists or occurs anything known about the participants in the (potential) communication relationship both at caller and callee: time CPL capabilities
caller preferences location location-based call routing location events activity/availability rich presence sensor data (mood, bio) not yet, but similar in many aspects to location data RPIDS: rich presence data Basic IETF presence (CPIM) only gives you contact information (SIP, tel URI) priority
open or closed Extend to much richer context information everything watcher PUA PA watcher PUBLISH NOTIFY "vague" watcher INVITE CPL Session mobility Walk into office, switch from cell phone to desk phone
call transfer problem SIP REFER related problem: split session across end devices e.g., wall display + desk phone + PC for collaborative application assume devices (or stand-ins) are SIPenabled third-party call control adaptive device configuration 802.11 signal strength location SLP
device controller REGISTER To: 815cepsr Contact: [email protected] PA all devices that are in the building RFC 3082? HTTP SUBSCRIBE to each room 1. discover room URI 2. REGISTER as contact for room URI tftp SIP SUBSCRIBE to configuration for users currently in rooms room 815 How to find services?
Two complementary developments: smaller devices carried on user instead of stationary devices devices that can be time-shared Need to discover services in local environment SLP (Service Location Protocol) allows querying for services large plasma displays projector hi-res cameras echo-canceling speaker systems
wide-area network access find all color displays with at least XGA resolution slp://example.com/SrvRqst?public?type=printer SLP in multicast mode SLP in DA mode Need to discover services before getting to environment is there a camera in the meeting room? SLP extension: find remote DA via DNS SRV Service Location Protocol (SLP) extended to meshed SLP (mSLP) for reliability and scaling SrvRqst SA UA SA SrvRply
SrvReg DA SrvRqst DAAdvert SrvReg Location-based services Presence-based approach: UA publishes location to presence agent (PA) becomes part of general user context other users (human and machines) subscribe to context call handling and direction location-based anycast (anybody in the room)
location-based service directory Languages for location-based services building on experience with our XML-based service creation languages CPL for user-location services LESS for end system services Location-based services in CINEMA Initial proof-of-concept implementation Integrate devices: lava lamp via X10 controller set personalized light mood setting Pingtel phone add outgoing line to phone and register user
painful: needs to be done via HTTP POST request stereo change to audio CD track based on user Sense user presence and identity: passive infrared (PIR) occupancy sensor magnetic swipe card ibutton BlueTooth equipped PDA IR+RF badge (in progress) RFID (in progress) biometrics (future) Location-based IM & presence Service creation
Promise of faster service creation traditionally, only vendors (and sometimes carriers) learn from web models programmer, end user carrier network servers SIP servlets, sip-cgi CPL end system VoiceXML VoiceXML (voice), LESS Service creation environment for CPL and LESS Ad-hoc wireless
infrastructure ./: Rescue service for web servers experiencing 15 minutes of fame Extend Apache: mod_dots, dotsd, DNS, mSLP State Transition
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