Internet2 RTC Forum April 21, 2004

Henning Schulzrinne

Xiaotao Wu

& CINEMA crewColumbia University

From multimedia conferencing to context-aware communications

2April 21, 2004

Overview Old challenge: any media, anywhere, anytime New challenge: appropriate and context-sensitive

communications not just telephony not just videoconferencing on-demand, not special equipment, setup, arrangements

Status of multimedia communications filling in the protocol matrix

On-going work: presence-enabled multimedia communications mobility terminal, personal, session, service creating new services in the web model, not the COBOL model

Location-based services Challenges ahead

3April 21, 2004

Internet services – the missing entry

Service/delivery synchronous asynchronous

push instant messaging

presence

event notification

session setup

media-on-demand

messaging

pull data retrieval

file download

remote procedure call

peer-to-peer file sharing

4April 21, 2004

Filling in the protocol gapService/delivery synchronous asynchronous

push SIP

RTSP, RTP

SMTP

pull HTTP

ftp

SunRPC, Corba, SOAP

(not yet standardized)

5April 21, 2004

SIP as service enabler Rendezvous protocol

lets users find each other by only knowing a permanent identifier

Mobility enabler: personal mobility

one person, multiple terminals

terminal mobility one terminal, multiple IP

addresses session mobility

one user, multiple terminals in sequence or in parallel

service mobility services move with user

6April 21, 2004

Example SIP phones

about $85

7April 21, 2004

Ubiquitous computing aspects Also related to pervasive computing Mobility, but not just cell phones Computation and communications Integration of devices

“borrow” capabilities found in the environment composition into logical devices

seamless mobility session mobility adaptation to local capabilities environment senses instead of explicit user interaction from small dumb devices to PCs

light switches and smart wallpaper

8April 21, 2004

Context-aware communications Traditional emphasis: communicate anywhere, anytime, any media largely

possible today New challenge: tailor reachability Context-aware communications

modify when, how, where to be reached machine: context-dependent call routing human: convey as part of call for human usage

context-aware services leveraging local resources awareness of other users

sources of location information voluntary and automatic

location-based services privacy concerns applies to other personal information activity, reachability, capabilities, bio sensor data, …

emergency services as a location-based service

9April 21, 2004

Context

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

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

both at caller and callee

time CPL

capabilities caller preferences

location location-based call routing

location events

activity/availability presence

sensor data (mood, bio) not yet, but similar in many aspects to location data

10April 21, 2004

“Legacy” IM & presence systems SIP-based systems centralized systems (single name space)

federated systems, similar to email mostly instant text messages

media-agnostic – transmit any media object separate from session-based services (VoIP, video

conferencing)integrated:

use IM as part of media sessionsuse presence to facilitate session setup

limited presence status, mostly manually setrich presence, with time informationimported from sensors, calendars, backend systems, …

proprietary systems (AOL, Yahoo!, MSN, ICQ, …)standards-based systems

11April 21, 2004

Presence and event notification Presence = special case of

event notification “user Alice is available for

communication” Human users:

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, …)

Multimedia systems: REFER (call transfer) message waiting indication conference floor control conference membership push-to-talk system configuration

General events: emergency alert (“reverse

911”) industrial sensors (“boiler

pressure too high”) business events (“more than

20 people waiting for service”)

12April 21, 2004

IETF efforts SIP, SIPPING and SIMPLE working groups

but also XCON (conferencing) Define SIP methods PUBLISH, SUBSCRIBE, NOTIFY GEOPRIV:

geospatial privacy location determination via DHCP information delivery via SIP, HTTP, … privacy policies

SIMPLE: architecture for events and presence configuration (XCAP) session-oriented IM (↔ page mode) filtering, rate limiting and authorization

13April 21, 2004

RPID: 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

14April 21, 2004

RPID: rich presence

Classification: contact-type

device, in-person, service, presentity

class for labeling

sphere “work”, “home”, …

relationship “family”, “associate”,

“assistant”, “supervisor”

Activities: activity

“on-the-phone”, “away”, “appointment”, …

idle last usage of device

Surroundings: placetype

“home”, “office”, “industrial”, …

privacy “public”, “private”

15April 21, 2004

CIPID: Contact Information

More long-term identification of contacts Elements:

card – contact Information home page icon – to represent user map – pointer to map for user sound – presentity is available

16April 21, 2004

Timed Status Presence is about here & now but often only have (recent)

past – e.g., calendar or future

“will be traveling in two hours” “will be back shortly”

allows watcher to plan communication

loose synchronization of calendars

<tuple id="7c8dqui">

<contact> sip:bob@example.com</contact><status> <basic>open</basic></status>

<fs:timed-statusfrom="2003-08-15T10:20:00.000-

05:00“until="2003-08-22T19:30:00.000-

05:00"><basic>closed</basic></fs:timed-status></tuple><note>I'll be in Tokyo next

week</note>

17April 21, 2004

GEOPRIV and SIMPLE architectures

targetlocationserver

locationrecipient

rulemaker

presentity

caller

presenceagent

watcher

callee

GEOPRIV

SIPpresence

SIPcall

PUBLISHNOTIFY

SUBSCRIBE

INVITE

publicationinterface

notificationinterface

XCAP(rules)

INVITE

DHCP

18April 21, 2004

Location-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

19April 21, 2004

Location-based SIP services Location-aware inbound routing

do not forward call if time at callee location is [11 pm, 8 am] only forward time-for-lunch if destination is on campus do not ring phone if I’m in a theater

outbound call routing contact nearest emergency call center send delivery@pizza.com to nearest branch

location-based events subscribe to locations, not people Alice has entered the meeting room subscriber may be device in room our lab stereo changes

CDs for each person that enters the room

20April 21, 2004

SIP URIs for locations

Identify confined locations by a SIP URI, e.g., sip:rm815@cs.columbia.edu

Register all users or devices in room

Allows geographic anycast: reach any party in the room

a@foo.com: 128.59.16.1

Room 815

sip:rm815

location beacon

Contact: alice

Contact: bob

21April 21, 2004

802.11 Location Tracking

Standard access pointsNo client software“Skiff” monitors

SA110 single board computer running Linux

Report signal strength, MAC address of all packets seen

by Jamey from HP

22April 21, 2004

Privacy Presence policy

subscriptionpolicy

event generatorpolicy

subscriberfilter

rate limiter

change to previousnotification?

for eachwatcher

subscriber (watcher)

SUBSCRIBE

NOTIFY

23April 21, 2004

Policy relationships

geopriv-specific presence-specific

common policy

RPID CIPID

future

24April 21, 2004

Privacy rules

Conditions identity, sphere, validity time of day current location identity as <uri> or

<domain> + <except> Actions

watcher confirmation Transformations

include information reduced accuracy

User gets maximum of permissions across all matching rules

Extendable to new presence data rich presence biological sensors mood sensors

25April 21, 2004

Example: user-adaptive device configuration

“all devices that are in the building”RFC 3082?

PA

devicecontroller

SUBSCRIBEto each room

SUBSCRIBE to configurationfor users currently in rooms

1. discover room URI2. REGISTER as contact for room URI

tftp

HTTP

SLP

802.11 signal strength

location

REGISTERTo: 815cepsrContact: alice@cs

SIP

room 815

26April 21, 2004

Location-based IM & presence

27April 21, 2004

Location-based call routing – UA knows its location

GPS

40.86N 73.98ECN=us A1=NJ A2=Bergen

INVITE sips:sos@

DHCP

outboundproxy server

provided by local ISP? 40.86N 73.98E: Leonia, NJ fire dept.

leonia.nj.us.sos.arpaPOLY 40.85 73.97 40.86 73.99NAPTR … firedept@leoniaboro.org

28April 21, 2004

Service creation

programmer, carrier

end user

network servers SIP servlets, sip-cgi

CPL

end system VoiceXML VoiceXML (voice),

LESS

Tailor a shared infrastructure to individual users traditionally, only vendors (and sometimes carriers) learn from web models

29April 21, 2004

Service creation environment for CPL and LESS

30April 21, 2004

location-switch for CPL

31April 21, 2004

Challenges Systems are still too hard to use without wizard

assistance: lack of interoperability (improving) NAT and other configuration volume mismatch, echo, …

audio problems not much changed since 1992 network/system fault diagnosis

Closed wireless systems – would be very nice presence sensors

Threat of “spim” and nuisance calls Provider platforms remain largely closed

promise of open service creation remains to be fulfilled

32April 21, 2004

Conclusion Standardization mostly complete

even if drafts don’t have RFC numbers yet Many commercial-grade, second-generation

products emerging both open-source and commercial emphasis on interoperability

Increasingly hostile network multi-layer NATs, random port blocking, “transparent”

proxies Usability and reliability remain too low

dial-in audio conference still common LCD problem (cf. MIME for email)