1. Combining VoiceXML with CCXML: A Comparative Study Daniel Amyot and Renato Simoes School of Information Technology and Engineering University of Ottawa, Canada damyot@site.uottawa.ca, renatops@yahoo.com

2. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Motivation Interactive Voice Response (IVR) applications –User interacts with an automated system Recorded speech or computer generated Telephone keys or speech recognition –Examples: Information retrieval, virtual secretaries, bookings and payments, … Popular IVR applications use: –VoiceXML for vocal dialogs –Session Initiation Protocol (SIP) for call control New Call Control eXtensible Markup Language (CCXML) emerging… Can CCXML help accelerate the development of complex VoIP solutions that have an IVR component?

3. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Overview VoiceXML (a.k.a. VXML) CCXML Comparative study based –Simple Personal Assistant system Observations VoiceXML Portability Issues Conclusions

4. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 VoiceXML Highlights Voice Extensible Markup Language –Version 2.0, W3C Recommendation (16 March 2004) Bring the advantages of Web-based development to IVR –Familiar client/server paradigm –Web Server keeps the logic (DB, generates VXML) –Multiple dialogs –Enables (voice) access to Web services Avoid low-level programming and resource management Designed for –Creating audio dialogs –Synthesized speech –Digitized audio –Speech recognition –DTMF key input –Recording –Basic telephony control

5. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 VoiceXML Example

6. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Typical Configuration with VXML (& SIP) Signalling and Call Control Voice Interactions Business Logic

7. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 CCXML Highlights Call Control eXtensible Markup Language –W3C Working Draft, 22 November 2006 (8 th version) Declarative description of advanced telephony functions –Conference control, Find Me Follow Me, click-to-dial, third- party call control manager… Handling of asynchronous events from many sources CCXML is protocol independent can interwork with voice dialogs –VoiceXML, Parlay, SLEE, JAIN SIP…

8. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 CCXML Benefits Handles sophisticated multiple call control –Ability to give each call leg its own dedicated IVR –Note possible with VoiceXML only Often SIP is added to solve this issue Suitable for direct interaction with end users –Necessary for IVR and conference services –Could not be done easily using IETF’s Call Processing Language (CPL)

9. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Typical Configuration with CCXML&VXML Signalling and Call Control Voice Interactions Business Logic

10. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Example Scenario: Personal Assistant

11. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 CCXML Example

12. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 '"/> Example of Complementary VoiceXML Script

13. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 CCXML vs SIP for Call Control CCXML SIP

14. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Typical SIP Message (INVITE) 09/07/2005 18:14:05.168: Outgoing Message Transport: UDP (reliable=false): ip=10.11.12.200, port=5060, plugin=null, forceUDP=false, TTL=1 INVITE sip:3334444@10.11.12.200:5060 SIP/2.0 Call-ID: 4AF4DBF6-A72611D5-9791C1FA-3D9B40D@10.11.12.200 From: ;tag=1975362409.1.kaaaaagpidddjkejhbchhkoc To: ;tag=7EB680D0-1A20 CSeq: 103 INVITE Contact: sip:sipserver:5060 Content-Type: application/sdp Content-Length: 362 Max-Forwards: 70 Via: SIP/2.0/UDP 10.0.0.246:5070;branch=z9hG4bK0A0000F6BADF00D00000104FD963E68191 v=0 o=SIP-GW-UserAgent 9597 1982 IN IP4 10.11.12.200 s=SIP Call c=IN IP4 10.11.12.200 t=0 0 m=audio 17968 RTP/AVP 18 0 8 4 2 3 19 c=IN IP4 10.11.12.200 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:4 G723/8000 a=fmtp:4 annexa=no a=rtpmap:2 G726-32/8000 a=rtpmap:3 GSM/8000 a=rtpmap:19 CN/8000

15. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Typical Scenario with VoiceXML & CCXML CCXML snippet seen earlier… VoiceXML script seen earlier…

16. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Same Scenario with VoiceXML & SIP

17. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Observations CriteriaSIP + VXML CCXML + VXML Comments Code Complexity HigherLowerCCXML code more abstract and smaller by an order of magnitude FlexibilityHigherLowerSIP can do all that CCXML can, but not the opposite MaintainabilityHigherLowerCCXML simpler to understand but its XML-based nature enables all sorts of errors hard to catch at design time ExtensibilityN/AHigher(CC)XML language easy to extend, but can lead to interoperability and portability issues CouplingLowerHigherCCXML server expected to be strongly coupled with the VXML browser. May have to come from same vendor or be on the same media server platform

18. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 VoiceXML Portability Issues Used VoiceXML media servers (Nuance’s NVP 3.0 and Brooktrout’s Snowshore A1) and studied Convedia and BeVocal Shadow Variables –Platform-specific, used to modify or access additional information from a VXML tag. –Nuance’s name$.termchar, name$.duration, name$.size Proprietary Grammar –Nuance includes its own Grammar Specification Language, used inside the VXML code Proprietary Tags –, –Nuance’s tags for voice recognition capabilities Partial Support for VXML 2.0 Others…

19. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 Conclusions CCXML provides appropriate abstractions and offers capabilities that are easier and faster to use than a plain SIP-based approach for IVR applications The SIP-level flexibility may still be required in some situations –Room for a hybrid solution? CCXML’s future will depend on the availability of good development and execution environments, including API’s Emerging CCXML platforms include: –Hewlett-Packard: HP Open Call Media Platform –Voxeo Corporation: Prophecy IVR Voice Platform –Loquendo: VoxNauta Platform

20. Combining VoiceXML with CCXML - CCNC'07, Las Vegas, Jan. 12, 2007 For Further Information Daniel Amyot Assistant Professor SITE, University of Ottawa 1-613-562-6800 ext. 6947 damyot@site.uottawa.ca