Internet Real Time (IRT) Lab at Columbia University

Professor: Henning SchulzrinneColumbia University

Presenter: Suman Srinivasan, PhD studenthttp://www.cs.columbia.edu/irt/

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…

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

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.

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

What is 7DS?

Internet

No Internet connection: Check with peers

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”

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

7DS Bulletin Board System

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

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

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

On-Path CDNs

–On-Path Content Distribution Network–Any NetServ node on path can, if it has

relevant content, serve content

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

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

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: hgs@cs.columbia.edu