What SALT can do for multivendor unified messaging environments

Today, we’re continuing our discussion on unified messaging. Speech Application Language Tags, like the Voice XML standard we explored last time, can be used to more easily integrate multivendor unified messaging applications. 

Like, VXML, SALT is also a Web-related markup language, and the SALT Forum is working with the World Wide Web Consortium (W3C) to garner additional support.  There are, however a few key differences between SALT and VXML. 

First, SALT is a newer standard, which was originally proposed in 2002 with backing from Microsoft and others.  As such, it has yet to be accepted or implemented with the wide-scale backing that VXML enjoys.  However, momentum to adopt SALT does seem to be gaining speed. 

Second, SALT is a “multimodal” access technology.  Unlike VXML, SALT can maintain multiple modes as either independent or concurrent “conversations per user” – albeit from voice, Web-based documents, keypads, keyboards, or mouse.  This access can produce replies from the application in the form of synthesized speech, audio, plain text, motion video, and/or graphics. 

Going back to our age-old “data guys vs. voice guys” debate, SALT has its roots in the Web and is greatly favored by Web developers, whereas VXML has the solid backing (and implementation) of nearly all communication systems suppliers.  However, both standards are likely to be adopted – much to the delight of users who want to more easily implement a multivendor unified messaging environment.

Protocol debates aside, VXML and SALT both provide a means for unified messaging to “branch out” beyond voice, fax, and e-mail and integrate other applications, such as document collaboration.  We’ll discuss in future issues the extension of unified messaging applications and portals into broader application areas.