Internet Real Time (IRT) Lab at Columbia University
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Internet Real Time (IRT) Lab at Columbia University
Professor: Henning SchulzrinneColumbia University
Presenter: Suman Srinivasan, PhD studenthttp://www.cs.columbia.edu/irt/
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Summary of our work
• Lots of interesting research!– Especially in the area of networking,
wireless and Voice-over-IP– Our advisor Dr. Schulzrinne had a key
role in the history of VoIP• He is the lead author for RFC documents on
RTP, RTSP, SIP protocols…
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Summary of our work
• List of our projects– Voice-over-IP
• Particularly SIP signaling protocol
– Wireless networks• How to make them faster (handoffs, etc.)• Mobile apps (yes, we build iPhone apps!)
– Core Internet• P2P file protocols: what makes them work• Web architectures• Service discovery
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Examples of our work
• Two research projects I’ve worked on– 7DS/BonAHA
• Wireless transient networks formed by mobile devices meeting each other are getting commonplace
• Need a new framework to run applications
– NetServ:• Internet core is – believe it or not – “dumb”• Simply transfers packets• If we introduced some “intelligence” into the network,
can we make it faster? – Think P2P, video streaming, etc.
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What is 7DS?
• Use local peer-to-peer wireless networks to exchange information– Peers can get information they do not
have from another peer• Once wireless 7DS network set up, it
could be used for any purpose– Getting web pages from peers– Sending e-mails– File transfer to selected client
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What is 7DS?
Internet
No Internet connection: Check with peers
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Share data from web
Columbia?
SRV : query._7ds._udp
TXT : columbia
TXT : news
TXT : new york
Times Square?
SRV : query._7ds._udp
TXT : deals
TXT : times square
TXT : weather
“Here is the result for times square”“Here is the result for
columbia”
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File transfer
SRV : filesync._7ds._udp
TXT : file1.xml
TXT : file2.xml
SRV : filesync._7ds._udp
TXT : word.doc
TXT : presentation.pptFile1.xmlFile2.xml
Word.docPresentation.ppt
“I wantWord.doc and presentation.ppt”
“I wantFile1.xml and file2.xml”
Word.docPresentation.ppt
File1.xmlFile2.xml
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7DS Bulletin Board System
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NetServ overview
Modularization
– Building Blocks
– Service Modules
Virtual services framework
– Security
– Portability
NSF FIND four-year project
– Columbia University
– Bell Labs
– Deutsche Telekom
– DOCOMO Euro-Labs
Extensible architecture for core network services
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CDNs: How YouTube Works
Original HTTP request for video
HTTP 301 redirect to
Google Video server (CDN)
HTTP 301 redirect to IP
address
Redirects user to closest video server
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Current CDN Technology
– Involves some redirection
– Youtube: HTTP redirection
– Inefficient “start up” time• In setting up
connection to CDN node
•From http://upload.wikimedia.org/wikipedia/commons/8/88/Akamaiprocess.png
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On-Path CDNs
–On-Path Content Distribution Network–Any NetServ node on path can, if it has
relevant content, serve content
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Demo: NetServ prototype•(1) Regular Incoming packets
•(2) “Operator” can view modules on router
•(3) Operator loads a new module (that makes all data uppercase)
•(4) Packets are modified
•(5) Operator stops the module
•(6) No more packet modification
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Current Work: CDN on NetServ
• On-Path CDN– Prototype implemented
• Dynamic content migration– Moving content closer to the end user
according to demand• Building blocks
– Network monitoring– Content discovery– Caching proxy
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Summary
• Internet Real Time Lab at Columbia University
• Presented two research projects– 7DS/BonAHA: wireless, transient
networks– NetServ: intelligence in network core
• More info:– Web: www.cs.columbia.edu/irt– E-mail: [email protected]