2. 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

3. 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

4. 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

5. Laboratory support Equipment grants and student support

6. 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

7. 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  7DS Service and event discovery (GloServ) Generic signaling protocols (GIMPS) for QoS, NAT/FW, … Autonomic computing service discovery  mSLP automated server pooling  DotSlash

8. 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)

9. 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

10. CINEMA components RTSP sipum Cisco 7960 sipvxml SIP rtspdsipconf LDAP server MySQL PhoneJack interface sipc T1 sipd media server RTSP SIP-H.323 converter messaging server unified server (MCU) user database conferencing sip-h323 VoiceXML server proxy/redirect server Cisco 2600 Pingtel wireless 802.11b PBX Meridian Nortel plug'n'sip

11. PSTN interworking Nortel PBX PSTN External T1/CAS Regular phone (internal) Call 9397134 1 SIP server sipd Ethernet 3 SQL database 4 7134 => bob sipc 5 Bob’s phone Gateway Internal T1/CAS (Ext:7130-7139) Call 7134 2 5551212

12. SIP emergency calling GPS 48° 49' N 2° 29' E INVITE sips:sos@ DHCP outbound proxy server 48° 49' N 2° 29' E  Paris fire department

13. 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

14. 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: timeCPL capabilitiescaller preferences locationlocation-based call routing location events activity/availability“rich” presence sensor data (mood, bio)not yet, but similar in many aspects to location data

15. 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 PA watcher PUA watcher PUBLISH NOTIFY everything "vague" CPL INVITE

16. 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 SIP- enabled third-party call control

17. PA device controller SUBSCRIBE to each room SUBSCRIBE to configuration for users currently in rooms 1.discover room URI 2.REGISTER as contact for room URI tftp HTTP Service mobility: user-adaptive device configuration SLP “all devices that are in the building” RFC 3082? 802.11 signal strength  location REGISTER To: 815cepsr Contact: alice@cs SIP room 815

18. How to find services? Two complementary developments: smaller devices carried on user instead of stationary devices devices that can be time-shared large plasma displays projector hi-res cameras echo-canceling speaker systems wide-area network access Need to discover services in local environment SLP (Service Location Protocol) allows querying for services “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

19. Service Location Protocol (SLP) extended to meshed SLP (mSLP) for reliability and scaling UA DA SA SrvReg SrvRply SrvRqst SrvReg DAAdvert

20. 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

21. 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)

22. Location-based IM & presence

23. Service creation programmer, carrier end user network servers SIP servlets, sip-cgi CPL end systemVoiceXMLVoiceXML (voice), LESS Promise of faster service creation traditionally, only vendors (and sometimes carriers) learn from web models

24. Service creation environment for CPL and LESS

25. Ad-hoc wireless infrastructure

26. ./: Rescue service for web servers experiencing 15 minutes of fame Extend Apache: mod_dots, dotsd, DNS, mSLP State Transition