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Internet Real-Time Internet Real-Time LaboratoryLaboratory
Prof. Henning Schulzrinne(presented by Kundan Singh)
http://www.cs.columbia.edu/IRT
OverviewOverview Columbia Networking Research Center
CS+EE networking groups; 15 faculty
IRT Lab 13 PhD 6 MS GRA 3 visitors 1 post doc
Research topicsResearch topics
Internet telephony Internet radio/TV
Content distribution
Wireless ad hoc networks
Resource reservation
Quality of serviceSecurity
VoIP and wireless
Internet service discovery
Peer-to-peer systems
Programmable Internet Programmable Internet telephonytelephony
Common gateway interface (CGI)
Call processing language (CPL)
SIP servlet
Make call when boss is online …
Enter your authentication PIN for billing…
B2BUA
Double ringing sound when boss calls…
Endpoint
Forward to office phone during day, and home phone during evening…
Proxy/registrar
Endpoint
Language for End System Services (LESS)
Use finger for locating user…
Messaging and device Messaging and device controlcontrol
Internet
DO sip:[email protected] SIP/2.0…..<Control><Action>turn lamp on</Action></Control>
VoIP for wireless LANVoIP for wireless LAN Problem
L2 Handoff time is too big (~500 ms) for seamless VoIP sessions (90 ms).
L2 Handoff procedure Scanning APs, Authentication,
Association The biggest component of handoff
time is the scanning time ( > 90%) Solution
Selective scanning (100-130 ms) Caching (2-4 ms)
Internet
911 for Internet telephony911 for Internet telephony Problems
Identify Route to PSAP Location
information Other issues
Record media Call taker GUI
ALI ServerDHCP Server
DNS Server
911112
sip:sos @ domainw/ location or w/ out location
geo location
POTS/Wireless Network
IP Network
911
IP Gateway
sip:sos @domainwithout location
Envinsa Server
sip:psap @domainwith location
location
GeoLynx Display
DHCP InformMAC Address
Location Info
TCP Socket Telephone Number
PSAP Info
HTTP SOAPgeo location
verifiedcivil
location
civil location**
PSAP Info
DNS Querycivil location
Next step in signaling Next step in signaling (NSIS)(NSIS) As part of the IETF NSIS working group, we are
standardizing a protocol for signaling information about a data flow along its path in the Internet.
The protocol supports various signaling applications, such as Quality of Service (QoS) and Network Address Translation (NAT) and Firewall traversal.
The protocol design adopts a two-layer approach, a lower layer for transport, and an upper layer specific to each signaling application.
We conducted Internet routing dynamics measurement and evaluated route change detection methods in typical NSIS deployment models.
Email by phoneEmail by phone
Login Email formatting Listen, reply,
delete, compose, forward
Navigation -next, previous, jump
Email formatting
SIP based Text-to-speech
VoiceXMLbrowser
Emailservlet
JSP
DB
procmailEmail
Email to IM
IM
Call
Internet
Internet
TTS
important mails
SIP
SIP
Internet
Internet
SIP
HTTP
Email by phone
Email to phoneInbox
Inbox
My owner’s SIP address is sip:[email protected]
Help!!! (invoke sipc to callsip:[email protected])
INVITE sip:[email protected]
Other past projectsOther past projects Location-based services: i-button, badge Voice and video mail Emergency 911 call routing File sharing among conference participants Phone announcement server Event notification to Phone, IM, email UDP-based link simulator Wireless ad-hoc networks QoS for audio conferencing Conference load balancing Conference floor control Peer-to-peer protocol analysis . . .
SummarySummary
Many research projects Multimedia, wireless, VoIP, services,… Prototype, measurement, study, …
PhD, MS GRA and grad/undergrad project students
More at http://www.cs.columbia.edu/IRT or email [email protected]
Reliable and scalable IP Reliable and scalable IP telephonytelephonyReliable and scalable SIP-based call routing and user
registration services for multimedia communication in our CINEMA architecture.
Server-based: improving single server performance, and load sharing.
Peer-to-peer: using distributed hash table such as Chord.
Goal: Carrier grade performance using commodity hardware
DotSlash – how to deal DotSlash – how to deal with 15 min of famewith 15 min of fame
Web hotspots Existing mechanisms are costly DotSlash
Enables a site utilize spare capacity of other site via dynamic collaboration
Location-basedLocation-basedServicesServices
InternalTelephonee.g., 7040
SIP/PSTN Gatewaye.g., Cisco 2600
Department PBX
Web based configuration
Web server
Telephoneswitch
SQLdatabase
sipd:proxy, redirect, registrar
H.323
rtspd: media server
sipum: unified messaging
RTSP clientse.g., Quicktime
RTSP
713x
CINEMA servers
sipconf: conference server
siph323: SIP-H.323 translator
Local/long distance e.g., 1-212-5551212
PSTN
SIP
VXML
vxml
cgi
7134
7136
[email protected](software phone) H.323 clients
e.g., NetMeeting
Session Initiation Protocol (SIP)- based enterprise VoIP infrastructure
...from VoIP to multimedia
collaboration…
