IMTC Forum 2005 1

From anywhere, anytime From anywhere, anytime communications to personalized communications to personalized communicationcommunication

Henning Schulzrinne(with Ron Shacham, Xiaotao Wu, Jonathan Lennox and

others)Department of Computer Science

Columbia Universityhgs@cs.columbia.edu

IMTC ForumMay 11, 2005 (Eibsee, Germany)

IMTC Forum 2005 2

OverviewOverview

Basic multimedia communication ready … but implementation lags 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 Other open issues in conferencing

IMTC Forum 2005 3

Collaboration in transitionCollaboration in transition

intra-organization;

small number of systems

(meeting rooms)

inter-organization

multiple technology generationsdiverse end

points

proprietary (single-vendor)

systems

standards-based solutions

IMTC Forum 2005 4

SIP is PBX/Centrex readySIP is PBX/Centrex readycall waiting/multiple calls

RFC 3261

hold RFC 3264

transfer RFC 3515/Replaces

conference RFC 3261/callee caps

message waiting message summary package

call forward RFC 3261

call park RFC 3515/Replaces

call pickup Replaces

do not disturb RFC 3261

call coverage RFC 3261

from Rohan Mahy’s VON Fall 2003 talk

simultaneous ringing

RFC 3261

basic shared lines

dialog/reg. package

barge-in Join

“Take” Replaces

Shared-line “privacy”

dialog package

divert to admin RFC 3261

intercom URI convention

auto attendant RFC 3261/2833

attendant console

dialog package

night service RFC 3261

centr

ex-s

tyle

featu

res

boss/admin features

attendant features

IMTC Forum 2005 5

An eco system, not just a An eco system, not just a protocolprotocol

SIP

XCAP(config)

RTSP

SIMPLEpolicyRPID

….

SDP

XCON(conferencing)

STUNTURN

RTP

configures

initiates carries

carriescontrols provide addresses

IMTC Forum 2005 6

SIP, SIPPING & SIMPLE –00 draftsSIP, SIPPING & SIMPLE –00 drafts

0

10

20

30

40

50

60

70

1999 2000 2001 2002 2003 2004

SIPSIPPINGSIMPLE

includes draft-ietf-*-00 and draft-personal-*-00

IMTC Forum 2005 7

SIP – a bi-cultural protocolSIP – a bi-cultural protocol

• overlap dialing• DTMF carriage• key systems• notion of lines• per-minute billing• early media• ISUP & BICC interoperation• trusted service providers

• multimedia• IM and presence• location-based service• user-created services• decentralized operation• everyone equally suspect

IMTC Forum 2005 8

Does it have to be that Does it have to be that complicated?complicated?

• highly technical parameters, with differing names• inconsistent conventions for user and realm• made worse by limited end systems (configure by multi-tap)• usually fails with some cryptic error message and no indication which parameter• out-of-box experience not good

IMTC Forum 2005 9

Aside: Why is Skype Aside: Why is Skype successful?successful? All the advantages of a proprietary protocol Peer-to-peer coincidental

only need 6 servers to support 10 million users Good out-of-box experience it just works

Software vendor = service provider Didn’t know that you couldn’t do voice quality beyond

PSTN others too focused on PSTN interoperability – why do

better voice than PSTN? Simpler solutions for NAT traversal

use TCP if necessary use port 80

Did encryption from the very beginning Kazaa marketing vehicle

IMTC Forum 2005 10

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 callee

time CPL

capabilities caller preferences

location location-based call routinglocation events

activity/availability presence

sensor data (mood, bio)

privacy issues similar to location data

IMTC Forum 2005 11

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

IMTC Forum 2005 12

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

IMTC Forum 2005 13

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

IMTC Forum 2005 14

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, …)

IMTC Forum 2005 15

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>

IMTC Forum 2005 16

Presence data modelPresence data model

“calendar” “cell” “manual”

alice@example.comaudio, video, text

r42@example.comvideo

person(presentity)

(views)

services

devices

IMTC Forum 2005 17

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

IMTC Forum 2005 18

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

IMTC Forum 2005 19

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>

IMTC Forum 2005 20

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

IMTC Forum 2005 21

Program location-based Program location-based servicesservices

IMTC Forum 2005 22

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

IMTC Forum 2005 23

Open issues for conferencing Open issues for conferencing standardizationstandardization

Multi-device systems and session mobility

Conference floor control BFCP simple RPC-like protocol

Centralized conference control (XCON WG) still struggling with control model

set + get variables (~SNMP) RPC-like model ( SOAP, XML-RPC, NETCONF) send descriptions? forms (XForms?)?

IMTC Forum 2005 24

Internet

CorrespondentNode (CN)

SIP UA

SLP UA

SIP SM

Local Devices

SLP SA SLP UA

SIP SM SIP UA

SLP DA

Mobile Node (MN)

SLPSIPRTP

SIP UA

Transcoder

Session mobilitySession mobility

IMTC Forum 2005 25

The conference treeThe conference tree Tree inheritance Each level can be addressed

via a URL Each layer links to parents

and children Lowest layer information

wins Parent can designate

variables that cannot be overridden (“forced global”)

Easily supports (corporate) policies recurring events with

exceptions modifying the active

conference only Probably also supports

side bars and other multi-policy configurations

permanent text chat rooms

Each node can reference scheduling information

but may not

all Acme Widget conferences

weekly eng. mtg.

instance 1

IMTC Forum 2005 26

XCON SystemXCON SystemLogical XCON Server

Floor ControlClient

TEMPLATEOf the SYSTEM:•Pre-configured•Initial/Default values

Conf EventNotification Server

Focus

CPCP Client

CCCPClient

CPCPServer

CCCPServer

CallSignaling

Client

TEMPLATE Policy:•Of TYPE RULES

RESERVATION Policy:•Of TYPE RULES

CURRENT Policy:•Of TYPE RULES

RESERVATIONOf the INSTANCE:•Of TYPE CONFERENCE-INFO

STATEOf the CURRENT INSTANCE:•Of TYPE CONFERENCE-INFO

NotificationClient

FloorControl Server

SIP/PSTN/H.323T.120/Etc.

CCCPCPCPSIP NOTIFY/Etc. BFCP

Logical XCON Client

IMTC Forum 2005 27

Open issues: application Open issues: application sharingsharing Current: T.120

doesn’t integrate well with other conference control mechanisms

hard to make work across platforms (fonts) ill-defined security mechanisms

Current: web-based sharing hard to integrate with other media, control and record generally only works for Windows mostly limited to shared PowerPoint

Current: vnc whole-screen sharing only can be coerced into conferencing, but doesn’t

integrate well with control protocols

IMTC Forum 2005 28

IETF effort: standardized IETF effort: standardized application sharingapplication sharing Remote access = application sharing Four components:

window drawing ops PNG keyboard input mouse input window operations (raise, lower, move)

Uses RTP as transport synchronization with continuous media but typically, TCP allow multicast large group sessions

IMTC Forum 2005 29

ConclusionConclusion Basic multimedia communication solutions

available scalable, secure, good quality

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

Application sharing as missing link Harder to maintain focus in the IETF

exhaustion, moving on to other things

IMTC Forum 2005 30

Backup slidesBackup slides

IMTC Forum 2005 31

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

IMTC Forum 2005 32

Presence data architecturePresence data architecture

candidatepresencedocument

watcherfilter

rawpresencedocument

post-processingcomposition(merging)

finalpresencedocument

differenceto previous notification

SUBSCRIBE

NOTIFY

remove data not of interest

watcher

IMTC Forum 2005 33

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>