CCXML — or Call Control eXtensible Markup Language — is the W3C (News - Alert) standard markup language for controlling how phone calls are placed, answered, transferred, conferenced, and more. CCXML is often mentioned in close proximity to its sister standard VoiceXML (News - Alert). Together the two standards provide a 100 percent standards- and XML-based solution for any telephony application.

 

While VoiceXML addresses the voice interface and the user interface, CCXML focuses on the call control functionality (answering phone calls, redirecting phone calls, call transfers and so on). The standards complement each other to address different parts of a telephony application.

 

I had the opportunity to speak with RJ Auburn, Chief Technology Officer, Voxeo (News - Alert) Corporation and Editor and Chair, of the W3C’s CCXML working group about the role of CCXML and the value it brings to developers.

 

According to Auburn, “It’s the missing piece to creating applications for the phone using Web technologies and using XML. Traditionally you could do things on a protocol level, but you would have to understand the details of the specific telephony protocol you were working with. There was simply no good standard that was simple to implement across different environments. If you were creating an application in say SIP, there wouldn’t necessarily be a good way to map that into the ISDN world.”

 

Using CCXML makes it simpler for developers who might have limited knowledge of telephony. Said Auburn, “CCXML takes the same Web-based approach that VoiceXML did to create voice applications. It uses the same founding principles to make it easier for application developers to use Web technologies and apply those to the call control side.

 

“It makes it easier for someone who doesn’t know a lot about telephony — someone who maybe has a bit of Web experience — to go in and create applications using CCXML to place an outbound call campaign, to manage telephone connections, and so on.”

 

I asked Auburn how prevalent CCXML is, and to describe how the standard was being received by developers.

 

According to Auburn, “Most of the major platform vendors have adopted CCXML as the standard for doing call control. Everyone from Voxeo to IBM (News - Alert), Nortel, Genesys... all those companies have gone ahead and adopted it.”

 

“CCXML has pretty good support across the industry,” he elaborated. “It’s being used to create all sorts of applications from outbound notification systems or appointment reminder systems or school notification systems... to more complicated use cases, such as session border controllers in the SIP world, or back to back user agents. Using CCXML, it’s easy to create applications and functionality that would be rather difficult to develop at the SIP level.”

 

So does it make sense to merge the two standards into one, build call control into VoiceXML, and create a single tool for developers to leverage when building their applications?

 

Not exactly.

 

According to Auburn VoiceXML and CCXML serve two different, but related needs.

 

“Some developers build applications that only use CCXML. For example, a session border controller probably doesn’t have any need for VoiceXML. On the flip side there may be VoiceXML applications that don’t need to do any call control at all.”

 

“From a standards perspective, it makes sense to keep the specifications separate so that hey can evolve along separate paths,” he added.

 

There are of course synergies that can be exploited since both standards were developed in the same organization (W3C).

 

Auburn explained that, “Both VoiceXML and CCXML are developed by the W3C’s Voice Browser working group to make sure that they support each other correctly.”

Voxeo leverages CCXML in their own product line as well.

 

“We have offered CCXML to our developers via our Prophecy on-demand hosting services and on-premise platforms. We offer it as a very easy framework for people to create telephony applications using CCXML itself. There are currently over 50,000 applications and 30,000 to 40,000 developers using CCXML and Prophecy to create them,” Auburn said.

 

“Every call that gets handled on the Voxeo network actually runs through CCXML sessions that manage the different portions of the call. Everything from our session border controllers, which sit at the edge of our network to connect to our different carriers, to our call routing applications internally… all of that ends up using CCXML.”

 

TMCnet readers interested in receiving more information on CCXML can take advantage of several readily available resources.

 

Voxeo’s developer portal has a whole suite of tutorials on CCXML, that are designed to take a novice who knows little or nothing about the standard to creating full-blown applications.

 

The company offers a “What is CCXML” page as well as a reference guide/tutorial for those interested in learning more about CCXML.

 

Another great resource is the W3C Web site. That’s where the specification actually “resides.” The site offers a detailed definition of the specification. The VoiceXML Forum Web site has some documentation on their site as well.

 

Regarding the future of the standard, Auburn maintains a bullish outlook, and sees increasing use of CCXML as it gets worked into a growing number of applications from traditional call center call management to the creation of brand-new, innovative communications applications.

 

“For people who are building applications for Facebook (News - Alert) or some of the other social networking platforms, it makes it very easy to manage many of those connections because CCXML has support for conferencing and placing phone calls and managing all the individual legs,” said Auburn. “I suspect we’ll start to see a lot more use in the social networking sphere, where the prevalent types of applications are used to connect people to each other. CCXML is provides a good framework for building that type of application.”