Transcript VoiceXML

Integrating VoiceXML
with SIP services
Kundan Singh, Ajay Nambi and Henning Schulzrinne
Columbia University
{kns10,an2029,hgs}@cs.columbia.edu
What is VoiceXML?
A language for specifying voice dialogs in
interactive voice response systems
Information retrieval
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News, sports, traffic, stock quotes, voice-mail
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e-business
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Customer service, banking, stock trading
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Notification service
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SIP/VoiceXML @ Columbia University
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Traditional IVR
PSTN
End user
Welcome to voice mail.
Press 3 to listen to new messages...
• 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)
1-212-8545224
IVR1 platform
• Voice and telephony functions
(ASR2, TTS3, DTMF4)
• Service logic (application specific)
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[1] Interactive voice response
[2] Automated speech recognition
[3] Text to speech
[4] Dual tone multi-frequency (touch tone)
[5] Public switched telephone network
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Decomposition
PSTN
End user
Internet
Voice gateway
• Voice and telephony functions
IVR platform
• Voice and telephony functions
(ASR, TTS, DTMF)
• Service logic (application specific)
Sep 2002
End user
Web server
• Service logic
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VoiceXML
PSTN
End user
Internet
Voice gateway VXML
• Voice and telephony functions
• VoiceXML browser
HTML End user
Multimedia
Web server
DB
Scripts
• Service logic (CGI, servlet, JSP)
Audio/
grammar
Web server
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HTML vs VoiceXML
<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>
Telephony, speech Synthesis or audio output, user input and
grammar, program flow, variable and properties, error
handling, …
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Further decomposition
PSTN
End user
Internet
End user
Voice gateway
Voice and
VoiceXML
telephony
browser
function
Web server
• Service logic (CGI, servlet, JSP)
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Internet telephony
SIP softphone
PSTN
End user
Internet
SIP/PSTN
gateway
SipVxml
Our Implementation of a
SipVxml Browser.
(Part of our CINEMA1
TestBed)
Media server
(RTSPd)
SIP hardware
phone
Web server (HTTPd)
[1] CINEMA - Columbia InterNet Extensible Multimedia Architecture
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Conferencing
SipVxml
Caller
1. INVITE sipvxml
2. Call accepted
3. Enter your four digit PIN
4. Entered 4-6-8-3
5. Authenticate user, 4683=>Alice
6. Enter the conference identifier
7. Entered 2-3-#
8. Permission to join, 23=>meet
9. REFER meet@conference
10.Terminate the old call
11.INVITE meet@conference
Call transfer vs bridged mode
Conference
server
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Ease & Flexibility
The ease & flexibility of SipVXML enables us to build
custom telephonic applications to suit our needs.
E.g Volume Check Application
1. INVITE sipvxml
2. Menu 1. Vol Check 2. Mic Check
3. User enters 2
4. User speaks out a voice sample
5. Voice sample is analyzed
6. SipVXML: Vol level too high/low/…
SipVxml
7. User adjusts the vol level.
7. User now joins conference.
Conference
server
Caller
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More usage in the CINEMA test-bed




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Unified messaging access
Email by phone
Event notification and scheduling
Audio volume level for conference
Advanced conference control
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Conclusions



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/
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