ubiquitous programmable internet telephony services

Ubiquitous Programmable Ubiquitous Programmable Internet Telephony Internet Telephony ServicesServices

Xiaotao WuInternet Real Time Laboratory

Thesis defense

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OverviewOverview

Where to put services Services

Ubiquitous – SIP-based ubiquitous computing

Programmable – CPL, LESS and FI handling Rich – existing services and new services Smart – Feature learning

Implementations Other works

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Ubiquitous Programmable Rich Smart


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Services can be everywhereServices can be everywhere

End devices

End users’ server

User agents in the network

Proxy server

B2BUA

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Where to put servicesWhere to put servicesEnd devices

End servers

Net UAs Proxy B2BUA

Number of users

Single Single/trusted users

Multiple Multiple Multiple

Call/dialog states

Yes Yes Yes No Yes

Media Yes Yes/no Yes No Yes/no

Number of entities

Single Multiple Single Multiple Multiple

Direct interaction

Yes No/yes No No No

Admin. End user End user Admin. Admin. Admin.

Store services in the network, though they may get executed in end systemsKeep the peer-to-peer architecture, avoid the master/slave architecture

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Peer-to-peer v.s. Peer-to-peer v.s. master/slavemaster/slave

Pickup call

D1 D2

D3

C

D1 D2

D3

C

notificationtriggeredINVITE

MGC

MGCPMegaco

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-- Mark Weiser

Ubiquitous computing using Ubiquitous computing using SIPSIP

What is ubiquitous computing Enhance computer use by making many computers

available throughout the physical environment, but making them effectively invisible to the user.

where are we

what’s available

how to controlautomate the control

Front deskService location server

room 123

what’s availablein room 123?

video displaymicrophonevideo camera

Bob I am in room 123

Bob can usedevices in 123

use the devicesin room 123 totalk to Tom

Tom

send mediato Tom

NOSSDAV03IEEE Communications

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System ArchitectureSystem Architecture

LocationSensing

ResourceDiscovery

ResourceControl

CallControl

GPS

BlueTooth

DHCP

Wireless triangulation

NOTIFY

PUBLISH

REGISTER

REGISTER

SIP Home domainRegistrar and AAA serverLocation

Server

Local domainSIP server

SLP DA

INVITE

SLP SA

SLP query

result

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Room confLocation agent

Bob

RFID readeriButtonreader

ProxyLS

Bob is in conf

NOTIFYLocation

You areIn conf

SLP DA

SLP SA

Device GWSLinke

X10

Turn onconf’s light

Turn on light

What’savailable

sip:conf_pingtelfor audio

sip:conf

Tracking

Triggeran action

Resourcediscovery

IEEE CCNC’05

Location-basedLocation-basedServices in our Services in our lablab

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Location-basedLocation-basedServices in our Services in our lablab

Location agent

Bob

RFID readeriButtonreader

ProxyLS

Bob is in conf

NOTIFYLocation

You areIn conf

SLP DA

SLP SA

Device GWSLinke

X10

Turn onconf’s light

Turn on light

What’savailable

sip:conf_pingtelfor audio

sip:conf

INVITE sip:anyone_roomconf

Guard communicatio

n behavior

‘Talk’ to alocation

Room conf

IEEE CCNC’05

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Location in Emergency Services

Emergency Call Center

Call Flow Prototype Architecture

SIP Proxy

SIP Proxy

Internet

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

IEEE ICCCN’05

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Program location-based Program location-based servicesservices<incoming> <LOC:where-switch type="civil"> <LOC:where country="USA" A1="New York" A3="New York" A6="West 120th" HNO="450" LOC="Room 563"> <location url="sip:[email protected]"> <redirect/> </location> </LOC:where> <otherwise> <location url="sip:[email protected]"> <redirect/> </location> </otherwise> </LOC:where-switch></incoming>

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Easy service creationEasy service creation

Using a tree-like structure to represent communication services

Natural thinking of call decision making – a rule set

For an incoming call, if I am in a conference, I will reject all the calls that are not from my boss.

A decision tree to represent a rule set

CPL and LESS

For an incoming call

If I am in a conference

Vibratemy device

Rejectthe call

YES

YES

NO

If the call is from my boss

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Timer Timer triggered triggered outgoing calloutgoing call

<?xml version="1.0" encoding="UTF-8"?><less xmlns="urn:ietf:params:xml:ns:less“ xmlns:IM="urn:ietf:params:xml:ns:less:im“ xmlns:xsi=“…" xsi:schemaLocation=“…"> <timer dtstart="20050307T110000Z"> <status-switch uri="sip:[email protected]" status-name="presence"> <status is="open"> <location url="sip:[email protected]"> <call> <busy> <location url="sip:[email protected]"> <IM:sendmsg> Hi, please call me back. I am in office </IM:sendmsg> </location>…………….

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CPL and LESSCPL and LESS CPL: Call Processing Language LESS: Language for End System Services Simple

Four kinds of elements: trigger, switch, action, modifier Tree-like structure, easy for feature interaction analysis

Safe Type safety: XML-based, no user defined variables Control flow safety: tree-like structure without back-reference No direct memory access Default behavior for every tree branch

Portability Handle user interactions and media operations Beyond call control

presence, IM, Web, location

IEEE ICC’03RFC3880

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LESS elementsLESS elementstrigger an incoming call

switch

check the caller

switchcheck time

switch

check priority

action

redirect

action

accept

action

reject

modifier

to Bob

= ≠

= ≠ ≠

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LESS elementsLESS elements

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LESS elementsLESS elements

Triggers incoming: incoming call handling outgoing: user invoked outgoing call timer: timer triggered actions UI:command: user interaction commands IM:message: incoming instant messaging Event:subscription: incoming subscription Event:notification: incoming notification

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LESS elements (cont.)LESS elements (cont.) Switches

time-switch: make decisions based on time address-switch: make decisions based on caller, callee

priority-switch: make decisions based on call priority string-switch: make decisions based on subject, … language-switch: make decisions based on languages status-switch: make decisions based on users’ status (remote user or local user, status includes presence, activity, mood, …, as listed in RPID)

Event:event-switch: check values in event notifications

LOC:where-switch: check users’ physical location information (remote or local user)

LOC:where-relation-switch: check relative physical locations between two people

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LESS elements (Cont.)LESS elements (Cont.) Actions

accept: accept an incoming call reject: reject an incoming call redirect: redirect an incoming

call authenticate: authenticate an

incoming request call: make an outgoing call terminate: disconnect a call wait: wait for a certain time

before next action mail: send email log: log request handling process Media:mediaupdate: update

media attributes Midcall:transfer: transfer a call

Midcall:merge: merge multiple calls UI:alert: alert user UI:getinput: get user input IM:sendmsg: send an instant message Event:approve: approve subscription Event:deny: deny event subscription Event:defer: defer the decision on

event subscription Event:subscribe: send subscription

out Event:notify: send notification out Queue:enqueue: put a call and its

context into a queue Queue:dequeue: get a call and its

context from a queue

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LESS elements (Cont.)LESS elements (Cont.) Two smaller concepts might be simpler

and more flexible than one more powerful but complicated concept

Modifiers location: to which a request to be directed lookup: lookup locations from a source remove-location: remove locations from

location set Media:media: provide media attributes

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Automatic Call Back (ACB)Automatic Call Back (ACB)<less xmlns="urn:ietf:params:xml:ns:less“ xmlns:Event="urn:ietf:params:xml:ns:less:event“ xmlns:Queue="urn:ietf:params:xml:ns:less:queue“ xmlns:xsi=“….“ xsi:schemaLocation=“……"><incoming> <status-switch status-name=“activity”> <status is=“on-the-phone"> <reject reason=“busy”> <next> <Queue:enqueue queue="callback"/> </next> </reject> </status> </status-switch></incoming>

In ITU Q.1211

“This feature allows the called party to automatically call back the calling party of the last call directed to the called party.”

Check my activity for an incoming call

Use Event and Queue extension

If I am on-the-phoneReject and enqueue

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<Event:notification> <address-switch field="origin"> <address uri="{agent.uri}"> <Event:event-switch> <Event:event package=“presence" name=“activity" is=“normal"> <Queue:dequeue queue="callback"> <Queue:success> <call/> </Queue:success> </Queue:dequeue> </Event:event> </Event:event-switch> </address> </address-switch> </Event:notification></less>

A event notification for myself

I am available

Dequeue and make a call

Automatic Call Back (ACB) Automatic Call Back (ACB) (cont.)(cont.)

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<?xml version="1.0"?><less> <incoming> <address-switch field="origin"> <address is="sip:[email protected]"> <accept/> </address> <otherwise> <location url="sip:[email protected]"> <redirect/> </location> </otherwise> </address-switch> </incoming></less>

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LESS script customizationLESS script customization

xsl:if

LESS editor

service.less(template)

XSLT

less.xsl

configurationeditor

service.html

translate.cgi

service_foo.less

address is=$var

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Open issuesOpen issues Can we use LESS for B2BUA?

‘lookup’ from database coordinate multiple sessions multi-user feature interaction handling

Loop and user-defined variables needed? Based on our exercises, no But, what about unknown new services? Convert loop to a high-level abstraction? What’s the impact on feature interaction

handling

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accept

accept

EasyEasy feature interaction analysis feature interaction analysis

Tree merging

+ =If time is between

10:00AM and 11:00AMIf address is hgs

Forward to conf

Incoming call Incoming call

Incoming call

If time is between 10:00AM and 11:00AM

If address is hgs

rejectForward to conf

rejectaccept

Take actions from both scripts. Simply setting precedence rules cannot work.ICFI’05 (FIW)

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Easy feature interaction Easy feature interaction analysisanalysis

FI handling between multiple CPL/LESS scripts Action conflict tables Tree merging algorithm Multi-component feature interactions

e.g., parallel forking with all end systems automatically accept an incoming call

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Pre-condition and expected Pre-condition and expected resultsresults

pre-condition expected results

accept The call setup is pending. The audio device is available.

The call setup is finalize. The communication session is setup. The audio device is occupied.

reject The call setup is pending. The call setup is finalized.

redirect

The call setup is pending. The call setup is finalized on the current end system.

call The audio device is available. If the callee side accepts the call, a communication session is setup and audio device is occupied.

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Action conflict tableAction conflict tableaccept reject redirec

tcall

accept A(media) C C R

reject C A(reason) C -

redirect

C C A(target) -

call R - - A(target)

-: no interaction, A: attribute conflict, C: action conflict,E: enabling, R: resource competition

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Tree mergingTree merging

set base-rule-set emptyforeach LESS-tree { convert the LESS-tree into a rule set foreach rule in the rule set { normalize the rule } merge the normalized rule set into base-

rule-set}convert base-rule-set into a decision tree

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Tree merging (cont.)Tree merging (cont.)if (two rules have different triggers) { no rule conflict except timer trigger} else if actions in two rules do not conflict { no rule conflict} else if no overlap between rule path in two rules { no rule conflict} else { two rules conflict with each other, return the rule path overlap and action conflict

information prompt to the script owner to judge}

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Rich signaling informationRich signaling information

Rich signaling information SIP headers Caller preference and callee capabilities MIME contents Event notification Other means

Web calendar, Directory services

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Rich servicesRich services Be able to handle services in PSTN networks

ITU Q.1211 ABD, ACB, CFC, CHA, QUE, CRG, OCS, …

Services in 5ESS switches Attendant camp-on, Automatic recall, …

Services in CSTA Phase III defined as signaling actions in LESS, e.g., mediaupdate

Emergency provide location information

New services Interact with existing Internet services

web, email, SLP, SAP, IM, presence, location, networked appliance control, directory service, calendar service, conferencing

Not named services, but programmable services Programmable conferencing services

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DefinitionDefinition

What is service learning Automatically generate user desired

services Help users, not bypass users Services on both proxy servers and end

systems What is service risk management

Risk caused by automation How to reduce the overall risks

IEEE ICC’05

43

MotivationMotivation Causal relationship between call information

and call decisions SIP headers Other Internet services

Learning burden caused by new services Not named services, but programmable services What and how

Examples Spam filtering, calendar-based services

Service risks Lose connectivity, lose privacy, …

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DesignDesign

Using decision tree induction for learning In CPL/LESS terms: find switches that

can best partition actions What algorithm

Incremental Prune Quality measurement

30*3+10*2+7=117 30*2+3*2+10*3+4*3=108

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Incremental Tree InductionIncremental Tree Induction Incremental

Incorporating Transposition

Virtual prune Direct metrics

Expected number of tests Leaf counts Minimum description length Expected misclassication cost

address=a1

time=t1 time=t1

B DCA

Y N

Y N Y N

time=t1

address=a1 address=a1

A DCB

Y N

Y N Y N

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Simulation

40 servicesEach for 300 calls80% match10% different way10% mismatch

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PerformancePerformance

Fast vs. incremental (20 samples) training

IBM ThinkPad, Linux 1GHz PIII Mobile256MB memory

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PerformancePerformance

20 vs. 250 incremental samples

IBM ThinkPad, Linux 1GHz PIII Mobile256MB memory

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IntegrationIntegration Gather information

Transaction history Calendar Location sensing Idle time Communication activities Timestamp

Alert users Service risk management

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Service risk managementService risk management Identify

Lose connection: reject, redirect, transfer, accept on wrong branch Lose privacy: accept, call, notify Lose money: accept, transfer to higher rate endpoint Lose attention: alert, accept, appliance control

Analyze Possibility: number of occurrence in the decision tree, switch

attributes Impact: (connection, privacy) > money > attention, customizable Overall risk: avoiding high impact risks, though may cause low

impact risks Resolve

Change communication methods Transfer Reduce overall risk

Contingency plan Backup

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ImplementationsImplementations

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Function overviewFunction overview

SIPMultimediacall control

Real time streaming

Location sensing

Network appliance control

Floorcontrol

SIP for presence

SAPInstantmessage

SIP CGI engine

LESS/CPLengine

Third party call control

Emergency handling

Service LocationDetection (SLP)

audio

video

whiteboard

desktopsharing

locationsensors

Email clients

RTP: RFC 1889SDP: RFC 2327RTSP: RFC 2326

SIP Event Arch.: RFC 3265 RFC3903

SAP: RFC 2974SIP: RFC 3261

SLP: RFC 2608

CPL, SIP 3PCC,SIP Device ControlGEOPRIV location format, SIP for IM

Web browsers

MMNS’04

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Call

SIP

SDPRTP

Session broadcasting SAP

RTSP

SIP eventnotification

Locationsensing

Emergency handling

Location tracking

Device controlir/x10

MapLynx

Messagewaitingindication

Voicemailhandling

Presencenotification

Conferencingfloor control

Servicedetection

SLP

Instantmessaging

xcon

Function reuseFunction reuse

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SDP

SAP

RTP

RTP

RTP

RTSP

SIP

SIP

SIP

location

SLP3pccSIP DO

SLPSIP

NOTIFY

MESSAGE

DO

SIP

location

location

Function interactionFunction interaction

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Other workOther work

Building Box project (AT&T Labs Research)

Conferencing floor control Networked appliance control Shared web browsing Joined some other projects (CINEMA,

SIP 911, session mobility, project for FAA, …)

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ConclusionConclusion

Services are more distributed in Internet telephony. We need techniques specifically for end system service creation

LESS is designed for end system services Easy to build SCE Easy to analyze Enable feature learning

Different information and different functions converged at end systems and will introduce many new services, e.g., location-based services.

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Some linksSome links SIPc: http://www.cs.columbia.edu/IRT/sipc CINEMA: http://www.cs.columbia.edu/IRT/cinema LESS: http://www.ietf.org/internet-drafts/draft-wu-iptel-less-00.txt Ubiquitous Computing: http://www1.cs.columbia.edu/~xiaotaow/

rer/Research/Paper/ieeecomm_inhome.pdf Service examples:

http://www.cs.columbia.edu/~library/TR-repository/reports/reports-2004/cucs-048-04.pdf

Feature interaction handling: http://www.cs.columbia.edu/ ~

xiaotaow/rer/Research/Paper/fiw.pdf Service learning: http://www.cs.columbia.edu/~xiaotaow/rer

/Research/Paper/icc2005.pdf

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AcknowledgementsAcknowledgements

Dr. Henning Schulzrinne SIPQuest Colleagues in IRT lab Colleagues in AT&T Labs Research

Thank you!

ubiquitous programmable internet telephony services

Documents

peer architecture

devicesin room

store services

whats availablein room

decision tree

pingtelfor audiosip

communication servicesnatural

rule setcpl