1. The Internet Real-Time Laboratory Henning Schulzrinne September 2003 http://www.cs.columbia.edu/IRT

2. Networking research at Columbia University Columbia Networking Research Center spans EE + CS 15 faculty – one of the largest networking research groups in the US about 40 PhDs spanning optical networks and wireless channels to operating systems, security and applications theory (performance analysis) to systems (software, protocols)

3. Laboratory overview Dept. of Computer Science: 32 faculty IRT lab: 13 PhD students includes 3 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

4. Laboratory support Equipment grants and student support

5. IRT topics Internet multimedia protocols and systems Internet telephony and radio (J. Lennox, X. Wu, K. Singh, W. Jiang, J. Rosenberg, A. Dutta, K. Koguchi; K. Butler, A. Nambi, S. Narayanan, A. Khwaja, S. Sridhar) Content distribution networks (L. Amini, Y. Nomura) Internet event distribution (P. Koskelainen, K. Arabshian) Wireless ad-hoc networks (M. Papadopouli, S. Sidiroglou)

6. IRT topics Quality of service Pricing for adaptive services (RNAP) (X. Wang) Scalable resource reservation protocols (P. Pan) BGRP for aggregation, YESSIR for applications, GIMPS for general signaling Fair multicast resource allocation (P. Mendes)

7. IP telephony: QoS estimation QoS estimation of voice traffic influence of loss correlation + FEC estimation via objective methods automated MOS estimation via speech recognition Planning: tools for automated end-to- end assessment

8. CINEMA Web interface Administration User configuration Unified Messaging Notify by email rtsp or http Portal Mode 3 rd party IpTelSP

9. 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

10. CINEMA Goal: fully integrated communications platform: synchronous + asynchronous collaboration calendaring multimedia collaboration: G.711 and high- quality audio, video, shared whiteboard, chat, shared applications Web control or VoiceXML interaction support pure VoIP and hybrids

11. Internet telephony: sipc Cross-platform tool for integrated multimedia communications Windows 98/NT/2K/XP Solaris, Linux, FreeBSD Support media plug-ins Screen sharing IM and presence programmable logic (cgi, CPL) Device control (electric appliances) (Emergency) notification Conference control (in progress)

12. 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

13. Internet telephony: emergency communications 911 services architecture emergency notification EPAD REGISTER sip:sos Location: 07605 302 Moved Contact: sip:sos@psap.leonia.nj.ussos@psap.leonia.nj.us Contact: tel:+1-201-911-1234 SIP proxy INVITE sip:sos Location: 07605

14. Languages for service creation Traditionally, telecom services created by switch vendors Web model: allow users and organizations to create custom services Two models: sip-cgi and CPL Sip-cgi: cgi scripts for call handling logic

15. Internet telephony: APIs APIs for IM and presence (JAIN JSR) design and implementation cooperation with Panasonic

16. Call Processing Language XML-based language

17. Mobile ad-hoc networks: 7DS Wireless infrastructure slow to emerge (Metricom, 3G $$$) 802.11b cheap and simple to deploy Mobile devices spread data in densely populated areas (e.g., NYC)

18. 7DS Content-independent: works for any web object Uses standard caching mechanism After 25’, 90% of interested users have data (25 hosts/ ) Also, data upload:

19. Ad-hoc wireless infrastructure

20. 7DS research issues Effects of power conservation, collaboration mechanism, wireless coverage range, density of devices on information dissemination e.g., how fast does information spread in such setting ? what is the average delay that a host experience until it gets the data ? Performance analysis via simulations and diffusion controlled processes theory

21. Mobility for Internet radio S1S2p1p2 BS0 BS1 Backbone Ad server Local Server m1 m2 Local Program RTSP Ad server Local Server m1 m2 Local Program RTSP BS2 M-Proxy (P1,a1) (P2,a2) P2,a2 P2,a3 S0 S1 (a1,a2) (a3)

22. Dotslash – A Web Hotspot Rescue System Web Hotspot A sudden, dramatic surge of request rate Short-term overload: long delay or no service Challenges Hard to predict Build up quickly Large magnitude

23. Dotslash Motivation One site can dramatically vary in request rate  insufficient capacity A group of sites  peak at different time, spared capacity at some sites Rescue service Dynamic collaboration among different sites Enable a site to expand its capacity dynamically and quickly

24. Functional Components Workload monitoring Discovery of spare capacity at other sites Request distribution and redirection Dynamic virtual hosting Dynamic replication of content Rescue relationship management

25. Basic Architecture Extend Apache: mod_dots, dotsd, DNS, mSLP State Transition

26. Fairness for multicast Intolerant (loss&delay) applications will use DiffServ Premium services, while tolerant applications can use Assured services; Multimedia flows multicast to heterogeneous receivers will use Assured services; Problem: Resources aren’t fairly distributed between flows inside a DiffServ service. Differentiated Service (DiffServ) networks divide traffic into different service quality levels, considering their quality requirements:

27. Multi-receiver fair allocation The number of receivers in each multicast flow; A maximal utilization of resources; Differential dropping between flows that overpass their share of service resources; A Multi-Receiver Utilization Maximal fair mechanism (MRUM) is being developed. Provide fair distribution of Assured services resources between multimedia multicast flows considering:

28. Quality of service: pricing Bandwidth: decrease of marginal returns  adaptive services Bandwidth Cost U1 U2 U3Budget

29. Bandwidth pricing Congestion pricing See GWB, turnpike, electricity Higher overall utility Prices constant for periods O(min) Auction or tatonnement pricing Charge for usage and reservation

30. Service location Enhancements to Service Location Protocol (SLP): reliability and scaling (meshed SLP) remote discovery attributes

31. Summary and future plans Personal and session mobility Service creation for VoIP Integrating the natural environment into IP communications Conferencing and conference control Ad-hoc and hybrid ad-hoc/infrastructure networks Emergency communications Network reliability