Internet2 spring meeting 1

Making the phone Making the phone notnot ringring

Henning SchulzrinneDepartment of Computer Science

Columbia Universityhgs@cs.columbia.edu

Internet2 spring meetingMay 3, 2005 (Arlington, VA)

Internet2 spring meeting 2

OverviewOverview Ring-and-hope presence-

mediated communications Uses for presence:

Old: “I’m on-line” Location-based services Presence-derived call handling Presence-derived trust

Presence and privacy

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Context-aware Context-aware communicationcommunication

context = “the interrelated conditions in which something exists or occurs”

anything known about the participants in the (potential) communication relationship

both at caller and calleetime CPLcapabilities caller preferenceslocation location-based call routing

location eventsactivity/availability presencesensor data (mood, bio)

privacy issues similar to location data

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Evolution of VoIPEvolution of VoIP

“amazing – thephone rings”

“does it docall transfer?”

“how can I make itstop ringing?”

1996-2000 2000-2003 2004-

catching upwith the digital PBX

long-distance calling,ca. 1930 going beyond

the black phone

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The role of presenceThe role of presence Guess-and-ring

high probability of failure: “telephone tag” inappropriate time (call

during meeting) inappropriate media (audio

in public place) current solutions:

voice mail tedious, doesn’t scale, hard to search and catalogue, no indication of when call might be returned

automated call back rarely used, too inflexible

most successful calls are now scheduled by email

Presence-based facilitates unscheduled

communications provide recipient-specific

information only contact in real-time if

destination is willing and able

appropriately use synchronous vs. asynchronous communication

guide media use (text vs. audio)

predict availability in the near future (timed presence)

Prediction: almost all (professional) communication will be presence-initiated or

pre-scheduled

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Basic presenceBasic presence Role of presence

initially: “can I send an instant message and expect a response?”

now: “should I use voice or IM? is my call going to interrupt a meeting? is the callee awake?”

Yahoo, MSN, Skype presence services: on-line & off-line

useful in modem days – but many people are (technically) on-line 24x7

thus, need to provide more context + simple status (“not at my desk”)

entered manually rarely correct does not provide enough context for directing

interactive communications

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Rich presenceRich presence More information automatically derived from

sensors: physical presence, movement electronic activity: calendars

Rich information: multiple contacts per presentity

device (cell, PDA, phone, …) service (“audio”)

activities, current and planned surroundings (noise, privacy, vehicle, …) contact information composing (typing, recording audio/video IM, …)

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Presence data modelPresence data model

“calendar” “cell” “manual”

alice@example.comaudio, video, text

r42@example.comvideo

person(presentity)

(views)

services

devices

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RPID = rich presenceRPID = rich presence Provide watchers with better information about

the what, where, how of presentities facilitate appropriate communications:

“wait until end of meeting” “use text messaging instead of phone call” “make quick call before flight takes off”

designed to be derivable from calendar information or provided by sensors in the environment

allow filtering by “sphere” – the parts of our life don’t show recreation details to colleagues

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The role of presence for call The role of presence for call routingrouting Two modes:

watcher uses presence information to select suitable contacts

advisory – caller may not adhere to suggestions and still call when you’re in a meeting

user call routing policy informed by presence

likely less flexible – machine intelligence

“if activities indicate meeting, route to tuple indicating assistant”

“try most-recently-active contact first” (seq. forking)

LESS

translateRPID

CPL

PA

PUBLISH

NOTIFY

INVITE

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Presence and privacyPresence and privacy All presence data,

particularly location, is highly sensitive

Basic location object (PIDF-LO) describes

distribution (binary) retention duration

Policy rules for more detailed access control

who can subscribe to my presence

who can see what when

<tuple id="sg89ae"> <status> <gp:geopriv> <gp:location-info> <gml:location> <gml:Point gml:id="point1“

srsName="epsg:4326"> <gml:coordinates>37:46:30N 122:25:10W

</gml:coordinates> </gml:Point> </gml:location> </gp:location-info> <gp:usage-rules> <gp:retransmission-allowed>no

</gp:retransmission-allowed> <gp:retention-expiry>2003-06-23T04:57:29Z

</gp:retention-expiry> </gp:usage-rules> </gp:geopriv> </status> <timestamp>2003-06-22T20:57:29Z</timestamp></tuple>

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Location-based servicesLocation-based services Finding services based on location

physical services (stores, restaurants, ATMs, …) electronic services (media I/O, printer, display,

…) not covered here

Using location to improve (network) services communication

incoming communications changes based on where I am configuration

devices in room adapt to their current users awareness

others are (selectively) made aware of my location security

proximity grants temporary access to local resources

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Program location-based Program location-based servicesservices

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Presence for spam Presence for spam preventionprevention VoIP spam (“spit”) and IM spam

(“spim”) likely to be more annoying than email spam

Subscription to another person is indication of mutual trust other person allows me to see their

status trusts me Thus, use watcher list (who is

watching me) as trust vector

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ConclusionConclusion Media delivery controlled

interaction Binary presence rich presence Presence as enabler of loosely-

coupled advanced services location-based services serve as service script inputs trust indicator for spit/spim prevention

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Backup slidesBackup slides

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Presence data architecturePresence data architecture

rawpresencedocument

createview

(compose)privacyfiltering

draft-ietf-simple-presence-data-model

compositionpolicy

privacypolicy

presence sources

XCAP XCAP

(not defined yet)

depends on watcherselect best sourceresolve contradictions

PUBLISH

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Presence data architecturePresence data architecture

candidatepresencedocument

watcherfilter

rawpresencedocument

post-processingcomposition(merging)

finalpresencedocument

differenceto previous notification

SUBSCRIBE

NOTIFY

remove data not of interest

watcher

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RPID: rich presenceRPID: rich presence<person>

<tuple>

<device>

<activities><class><mood><place-is><place-type><privacy><relationship><service-class><sphere><status-icon><time-offset><user-input>