The Internet Real-Time The Internet Real-Time LaboratoryLaboratory

Henning Schulzrinne CS Seminar

September 10, 2001

Laboratory overviewLaboratory 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 topicsIRT 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 topicsIRT 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 multimediaInternet 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

CINEMACINEMA Web interface

Administration User

configuration Unified

Messaging Notify by email rtsp or http

Portal Mode 3rd party IpTelSP

CINEMA architectureCINEMA architecture

SIP/RTSPUnified

messaging

RTSP media server

Quicktime

SIP proxy,redirectserver

SQLdatabase

SIPH.323convertor

NetMeeting

H.323

SIP conference

server

T1/E1 RTP/SIP

Telephoneswitch

Web server

Software SIP user agent

SNMP

PSTN interworkingPSTN interworkingNortel PBXPSTN

External T1/CAS

Regular phone(internal)

Call 93971341

SIP server

sipd

Ethernet

3

SQLdatabase

4 7134 => bob

sipc

5

Bob’s phone

GatewayInternal T1/CAS(Ext:7130-7139)

Call 71342

5551212

Languages for service Languages for service creationcreation 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 LanguageCall 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: Mobile ad-hoc networks: 7DS7DS 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)

7DS7DS Content-independent: works for

any web object Uses standard caching mechanism After 25’, 90% of interested users

have data (25 hosts/ ) Also, data upload:

2km

7DS research issues7DS 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

Mobility for Internet radioMobility for Internet radioS1 S2p1 p2

BS0 BS1

Backbone

Ad server

LocalServer

m1

m2

LocalProgram

RTSP

Ad server

LocalServer

m1

m2

LocalProgram

RTSP

BS2

M-Proxy

(P1,a1) (P2,a2)P2,a2

P2,a3

S0

S1

(a1,a2)

(a3)

Fairness for multicastFairness 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 Differentiated Service (DiffServ) networks divide traffic into different service quality divide traffic into different service quality levels, considering their quality levels, considering their quality requirements:requirements:

Multi-receiver fair Multi-receiver fair allocationallocation

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 Provide fair distribution of AssuredAssured services resources between multimedia services resources between multimedia multicast flows considering:multicast flows considering:

Quality of service: pricingQuality of service: pricing Bandwidth: decrease of marginal

returns adaptive services

Bandwidth

CostU1 U2

U3 Budget

Bandwidth pricingBandwidth 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