Integrating VoiceXML with SIP services

1
Integrating VoiceXML with SIP services

• Kundan Singh, Ajay Nambi and Henning Schulzrinne
• Columbia University
• kns10,an2029,hgs_at_cs.columbia.edu

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

3
Traditional IVR

• 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)

PSTN
End user
Welcome to voice mail. Press 3 to listen to new
messages...
1-212-8545224
IVR1 platform

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

1 Interactive voice response 2 Automated
speech recognition 3 Text to speech 4 Dual
tone multi-frequency (touch tone) 5 Public
switched telephone network
4
Decomposition
PSTN
End user
IVR platform

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

5
VoiceXML
PSTN
Internet
End user
VXML
Voice gateway
HTML

• Voice and telephony functions
• VoiceXML browser

Web server

• Service logic (CGI, servlet, JSP)

6
HTML vs VoiceXML
ltformgt ltfield nameidgt ltpromptgt
Your ID, please. lt/promptgt lt/fieldgt
ltblockgt ltsubmit nexturl/gt
lt/blockgt lt/formgt
ltform actionurlgt Enter your Id ltinput
nameidgt ltinput typesubmitgt lt/formgt
Telephony, speech Synthesis or audio output, user
input and grammar, program flow, variable and
properties, error handling,
7
Further decomposition
PSTN
Internet
End user
Voice gateway
Voice and telephony function
VoiceXML browser
Web server

• Service logic (CGI, servlet, JSP)

8
Internet telephony
SIP softphone
PSTN
Internet
End user
SIP/PSTN gateway
SipVxml
SIP hardware phone
Our Implementation of a SipVxml Browser. (Part
of our CINEMA1 TestBed)
Web server (HTTPd)
1 CINEMA - Columbia InterNet Extensible
Multimedia Architecture
9
Conferencing
1. INVITE sipvxml
2. Call accepted
3. Enter your four digit PIN
4. Entered 4-6-8-3
5. Authenticate user, 4683gtAlice
6. Enter the conference identifier
7. Entered 2-3-
8. Permission to join, 23gtmeet
SipVxml
9. REFER meet_at_conference
10.Terminate the old call
Caller
11.INVITE meet_at_conference
Call transfer vs bridged mode
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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/
7. User adjusts the vol level.
SipVxml
7. User now joins conference.
Conference server
Caller
11
More usage in the CINEMA test-bed

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

12
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/