[January 15, 2001] CallXML is one of several 'phone markup languages' supported by Voxeo in its development of web technologies which "enable web developers, service providers and business enterprises to rapidly create and easily deploy applications for an existing market of 1.5 billion telephone users. voxeo's network infrastructure lets any telephone or cell phone interact with web based applications, residing on traditional web servers, using phone markup languages." According the web site description, CallXML is "an XML based markup language used to describe the user interface of a telephone, voice over IP, or multi-media call application to a CallXML browser. A CallXML browser can then use that description to control and react to the call itself. CallXML includes: (1) Media action elements such as <playAudio> and <recordAudio> to describe what to present to the user during a call. (2) Call action elements such as <answer>, <call>, and <hangup> to describe how to control and route the call itself. (3) Logic action elements such as <assign>, <clear>, and <goto> to describe how to modify variables and interact with traditional server-side web logic such as perl, other cgi languages, PHP, or ASP. (4) event elements such as <onTermDigit>, <onHangup> to describe how to react to things the user can do during the call, such as pressing digits or hanging up. (5) block elements which logically group actions and events together, so that one set of event handling elements can be used for several sequential actions. In contrast to VoiceXML, CallXML uses a more simplified block / action / event interface model, which can be easier to learn and which allows for visual design tools which directly represent CallXML markup as simple flow-chart like user interfaces. VoiceXML is designed to make it easy for web developers to create voice recognition based interfaces for either telephones or computer-based applications. As such, VoiceXML is an excellent solution for voice based applications which provide access to web content and information, including applications which allow users to retrieve web content via phone (ie: voice portals, web-by-phone, audiotex, etc) and applications which allow users to interact with web based services using spoken commands (i.e., stock quotes, sports scores, etc). CallXML was designed to make it easy for web developers to create applications that can interact with and control any number or type calls, including: (1) Telephone or Voice over IP call applications which can control the initiation and routing of a phone call itself, supporting such features as outbound dialing, conferencing, and multi-call interactions (ie: conference bridges, internet call waiting, follow-me/find-me, etc) (2) Telephone or Voice over IP call applications which can easily interact and respond to touch-tone based entry and selection (ie: voicemail, interactive voice response, etc) (3) Call Applications which include support for additional media, such as faxes and video (i.e., unified messaging, video conferencing, etc)" [adapted from the Overview]
References:
[January 15, 2001] "Voxeo Speaks Out. [Vision Thing.]" By Bill Michael and John Jainschigg. In ComputerTelephony (January 05, 2001), pages 32-36. ['What's left to do, after breaking up Microsoft? Star antitrust attorney Gary Reback has turned entrepreneur - his startup, Voxeo, is building a network of open-platforms-in-the-sky for telephony application development and hosting.'] "Gary Reback has quit practicing law and founded a high-tech startup - in the process, handing biz/tech journalists one of the year's juciest storyline hooks. Reback's new company, Voxeo (Scotts Valley, CA - 831-439-5130) proposes to solve the 'telephony problem' for web-centric developers. They're building a community, providing low-or-no-cost tools, and inventing cooperative strategies to simplify XML-based telephony application development and remote testing; exploiting popular and broadly-supported XML variants such as VoiceXML and WML (plus a CallXML variant of their own) at toplevel. They're engineering middleware that coordinates between TML (Telephony Markup Language - our generic term for beasts like VoiceXML) scripts and the scary, underlying phone stuff; and permits remote integration of telephony to existing e-commerce back-ends. Ultimately, they aim to become profitable by hosting the 'telephony parts' of applications on a national network of servers. In a sense, it's a 'global platform play.' But with a distinctly open, Internet twist. Broadly-supported telephony markup langauges at the front end neatly abstract away from the underlying middleware and hardware, eliminating fears of lock-in. The development model is simple: compose a one-call app description, post it, and watch the middleware run it on an arbitrary number of lines. The prohibitive cost of buying a development platform is eliminated, as are fears that the app you write on a small development system won't scale neatly to higher line-counts and traffic metrics. Voxeo has designed their middleware so that (in theory) you don't have to worry about that stuff. And of course, integrating with your existing e-commerce infrastructure is close-to-transparent, since it's all happening at the level of XML scripts browser data-models, and arbitrary URL references..."
[January 15, 2001] "Voxeo Opens Telephony to Web Developers." By Shannon Cochran. In DDJ News (November 2000). "'Telephony's historic protocols and media and tools are viciously hard to get into,' counsels John Jainschigg, Editor-in-Chief of Computer Telephony. Jainschigg says the challenge exists, -- 'because there's a whole new vocabulary to learn, and because the protocols address...the vagaries and arcane characteristics of a heterogeneous global analog/digital hybrid phone network.' But a startup called Voxeo may be poised to help web developers enter this formidable new world. Founded this year by Jonathan Taylor and Gary Reback (of Microsoft antitrust fame), Voxeo plans to operate as an ASP of telephony, charging customers for use of its phone-to-web infrastructure. Its goal is to simplify the process of creating and deploying phone/Web applications... Hoping to attract developers to its infrastructure, Voxeo has launched a 'developer community portal' featuring tutorials, reference applications, a graphical design tool, and 24-hour technical support for developers. The services are all free, at least until January 15, 2001. Voxeo's applications reside on traditional web servers, but use phone markup languages -- VoiceXML, Microsoft's Web Telephony Engine, or Voxeo's own CallXML language -- to describe the presentation of a phone call instead of a web page. 'CallXML is useful for handling call control actions such as placing an outbound call or conferencing calls together. CallXML is also useful for easily detecting keyed input from a telephone,' explains the developer site. 'VoiceXML is useful for handling voice recognition as well as connecting users to existing web content.' Voxeo's system can also incorporate Perl, PHP, ColdFusion, JRun, and Active Server Pages. Voxeo Designer, also offered on the site, is a visual design environment for the phone mark-up languages. Possible applications within the Voxeo system include unified messaging, follow-me find-me, Internet call waiting, phone-enabled instant messaging, web-to-phone notifications, virtual call centers, broadcast fax or voice messages, and multimedia conference calling. The developer's site includes open-source programs of these types: Voxeo is planning to move some of them to SourceForge. Voxeo is also currently providing a network for test deployment."
