Integrating Integrating VoiceXML with SIP VoiceXML with SIP servicesservices

Kundan Singh, Ajay Nambi and Henning SchulzrinneColumbia University

{kns10,an2029,hgs}@cs.columbia.edu

Sep 2002 SIP/VoiceXML @ Columbia University 2

What is VoiceXML?

A language for specifying voice dialogs in interactive voice response systems

Information retrieval News, sports, traffic, stock quotes, voice-mail

e-business Customer service, banking, stock trading

Notification service

Sep 2002 SIP/VoiceXML @ Columbia University 3

Traditional IVRTraditional IVR

End userEnd user

IVRIVR1 platform platform• Voice and telephony functions (ASR2, TTS3, DTMF4)• Service logic (application specific)

• Receives incoming PSTN5 call• Responds back with prompts• Accepts user input (DTMF or speech)• Takes action based on user input

(Usually the service logic is programmed for the specific

application, say weather report)

[1] Interactive voice response[2] Automated speech recognition[3] Text to speech [4] Dual tone multi-frequency (touch tone)[5] Public switched telephone network

Welcome to voice mail. Press 3 to listen to new messages...

1-212-8545224

PSTNPSTN

Sep 2002 SIP/VoiceXML @ Columbia University 4

End userEnd user

IVR platformIVR platform• Voice and telephony functions (ASR, TTS, DTMF)• Service logic (application specific)

DecompositionDecomposition

PSTNPSTN

End userEnd userVoice gatewayVoice gateway• Voice and telephony functions

Web serverWeb server

• Service logic

Internet

Internet

Sep 2002 SIP/VoiceXML @ Columbia University 5

End userEnd userVoice gatewayVoice gateway

Web serverWeb server

• Service logic (CGI, servlet, JSP)

• Voice and telephony functions• VoiceXML browser

End userEnd userVXMLVXML HTMLHTML

DB

Multimedia

Audio/grammar

Scripts

Web server

VoiceXMLVoiceXML

PSTNPSTN Internet

Internet

Sep 2002 SIP/VoiceXML @ Columbia University 6

<form action=“url”> Enter your Id: <input name=‘id’> <input type=‘submit’> </form>

<form> <field name=‘id’> <prompt> Your ID, please. </prompt> </field> <block> <submit next=“url”/> </block></form>

HTML vs VoiceXMLHTML vs VoiceXML

Telephony, speech Synthesis or audio output, user input and grammar, program flow, variable and properties, error handling, …

Sep 2002 SIP/VoiceXML @ Columbia University 7

End userEnd userVoice gatewayVoice gateway

Web serverWeb server

• Service logic (CGI, servlet, JSP)

End userEnd user

Further decompositionFurther decomposition

PSTNPSTN Internet

Internet

Voice and telephonyfunction

VoiceXML browser

Sep 2002 SIP/VoiceXML @ Columbia University 8

End userEnd user SIP/PSTNSIP/PSTNgatewaygateway

Internet telephonyInternet telephony

PSTNPSTNSIP softphoneSIP softphone

SipVxmlSipVxml SIP hardware SIP hardware phonephone

Web server (HTTPd)Web server (HTTPd)

Internet

Internet

Media serverMedia server(RTSPd)(RTSPd)

Our Implementation of a Our Implementation of a SipVxml Browser.SipVxml Browser.

(Part of our CINEMA(Part of our CINEMA11 TestBed)TestBed)

[1] CINEMA - Columbia InterNet Extensible Multimedia Architecture

Sep 2002 SIP/VoiceXML @ Columbia University 9

ConferencingConferencing

SipVxmlSipVxml

CallerCaller

Conference Conference serverserver

1. INVITE sipvxml2. Call accepted3. Enter your four digit PIN4. Entered 4-6-8-3

5. Authenticate user, 4683=>Alice6. Enter the conference identifier7. Entered 2-3-#

8. Permission to join, 23=>meet9. REFER meet@conference10.Terminate the old call

11.INVITE meet@conference

Call transfer vs bridged mode

Sep 2002 SIP/VoiceXML @ Columbia University 10

Ease & FlexibilityEase & Flexibility

SipVxmlSipVxml

CallerCaller

1. INVITE sipvxml2. Menu 1. Vol Check 2. Mic Check3. User enters 2

4. User speaks out a voice sample5. Voice sample is analyzed6. SipVXML: Vol level too high/low/…

7. User adjusts the vol level.

The ease & flexibility of SipVXML enables us to build custom telephonic applications to suit our needs.

E.g Volume Check Application

Conference Conference serverserver

7. User now joins conference.

Sep 2002 SIP/VoiceXML @ Columbia University 11

More usage in the CINEMA test-More usage in the CINEMA test-bedbed

Unified messaging access Email by phone Event notification and scheduling Audio volume level for conference Advanced conference control

Sep 2002 SIP/VoiceXML @ Columbia University 12

ConclusionsConclusions VoiceXML is simple and exciting Sipvxml is useful for IP telephony and

regular telephony Numerous easy to develop applications

http://www.cs.columbia.edu/IRT/cinema/doc/sipvxml.html

http://www.cs.columbia.edu/IRT/cinema

http://www.w3.org/Voice/