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The Internet Real-Time Laboratory. Henning Schulzrinne CS Seminar September 10, 2001. Laboratory overview. 12 PhDs 4 at IBM, Juniper, Lucent, Telcordia 5 MS 5 visitors (Ericsson, Fujitsu, Mitsubishi, Nokia, U. Coimbra)
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The Internet Real-Time Laboratory Henning Schulzrinne CS Seminar September 10, 2001
Laboratory overview • 12 PhDs • 4 at IBM, Juniper, Lucent, Telcordia • 5 MS • 5 visitors (Ericsson, Fujitsu, Mitsubishi, Nokia, U. Coimbra) • China, Finland, Greece, India, Japan, Portugal, Spain, Sweden, US, Taiwan
IRT topics • Internet multimedia protocols and systems • Internet telephony and radio (J. Lennox, X. Wu, K. Singh, K. Arabshian, W. Jiang, J. Rosenberg, A. Dutta) • Content distribution networks (L. Amini, Y. Nomura) • Internet event distribution (P. Koskelainen) • Wireless ad-hoc networks (M. Papadopouli, S. Sidiroglou)
IRT topics • Service discovery (W. Zhao) • Quality of service • Pricing for adaptive services (X. Wang) • Scalable resource reservation protocols (P. Pan) • Fair multicast resource allocation (P. Mendes)
Internet multimedia • Internet telephony = replacing the existing circuit-switched system with Internet-based systems • Signaling = setting up calls • Quality of service • Subjective evaluation of speech codecs, when subjected to packet loss • Forward error correction at packet level
CINEMA • Web interface • Administration • User configuration • Unified Messaging • Notify by email • rtsp or http • Portal Mode • 3rd party IpTelSP
SIPH.323 convertor Web server CINEMA architecture Quicktime SNMP RTSP media server SIP/RTSP Unified messaging SIP conference server Telephone switch SIP proxy, redirect server SQL database T1/E1 RTP/SIP NetMeeting H.323 Software SIP user agent
Nortel PBX Gateway PSTN Internal T1/CAS (Ext:7130-7139) External T1/CAS Call 9397134 Call 7134 Ethernet 4 5 2 1 3 5551212 Regular phone (internal) SIP server SQL database sipd sipc Bob’s phone 7134 => bob PSTN interworking
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
Call Processing Language • XML-based language <incoming> <address-switch field="origin" subfield="host"> <address subdomain-of="example.com"> <location url="sip:jones@example.com"> <proxy> <busy> <sub ref="voicemail" /> </busy> <noanswer> <sub ref="voicemail" /> </noanswer> <failure> <sub ref="voicemail" /> </failure> </proxy> </location> </address> <otherwise> <sub ref="voicemail" /> </otherwise> </address-switch> </incoming>
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)
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:
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
m1 Local Server m2 RTSP Local Program Ad server Mobility for Internet radio p1 S1 S2 p2 M-Proxy Backbone S1 S0 m1 Local Server m2 RTSP Local Program Ad server (a1,a2) (a3) BS1 BS0 BS2 (P1,a1) P2,a3 (P2,a2) P2,a2
Fairness for multicast Differentiated Service (DiffServ) networks divide traffic into different service quality levels, considering their quality requirements: • 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.
Multi-receiver fair allocation Provide fair distribution of Assured services resources between multimedia multicast flows considering: • 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.
Cost U1 U2 U3 Budget Bandwidth Quality of service: pricing • Bandwidth: decrease of marginal returns adaptive services
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