By aligning communications with service-oriented architecture (SOA) as part of a company's enterprise application integration (EAI) strategy, developers can take communications and enterprise application development to the next level by integrating voice communication capabilities with critical business applications and processes.

EAI has been around for decades and is not going anywhere, as companies have invested heavily in back-office systems such as customer resource management (CRM), enterprise resource planning (ERP), and supply chain management systems. However, companies that want to remain competitive must rethink their communications strategy and how their communications networks are built.

To get ahead of the competition, companies need to extend communications beyond basic interactive voice response (IVR) systems and proprietary back-office applications, such as the customer relationship management systems of the past. These systems still serve their purpose and need not be tossed aside. Companies can make use of existing enterprise applications, however, and developers can better bind systems in back-office business applications through communications Web services implemented in an SOA.

Case in Point
Let's take a look at an example application of communications Web services in an SOA.

The company considering using an SOA model consists of three components—a service, a provider, and consumers. Let's consider an insurance company (provider) that processes claims (a service) for its customers/drivers (consumers). The company implements an insurance claim resolution process using communication-enabling Web services to notify its appraiser when a claim needs to be resolved, along with other critical alerts.

The system consists of an insurance claim application that kicks off an event to alert the appraiser to resolve a claim, which happens through the application platform. A Web service called PRESENCE indicates that the appraiser is on another call. The system then alerts the appraiser via an instant message, using the IM_MESSAGE Web service. The instant message includes either the URL of the insurance claim or the identifier for the claim. The appraiser then completes his previous call and clicks the Click to Call button, which invokes the CLICK_TO_CALL Web service. At this point, the application calls the customer through the private branch exchange (PBX), Avaya Communication Manager, using the TELEPHONY_SERVICE Web service. The appraiser needs the assistance of a collision expert, so he conferences the expert into the call, using the CLICK_TO_CONFERENCE Web service.

Common Communications-enabled SOA
Avaya enables integration through interoperability with its standardized approach to voice-based applications that support business processes via a communications-based SOA, using industry standard protocols.

Implementing EAI and SOA are table stakes if you want to compete in today's marketplace, said Sean Moore, Ph.D., and Enterprise Architect within Avaya's CTO organization. "Forward-thinking companies require Avaya to provide EAI based on the SOA model."

Let's delve into the Avaya technologies that take voice-enabled applications to the next level in enterprise application development for these forward-thinking companies.

An enterprise application that integrates with the communications services in the Avaya SOA includes the following Avaya technologies and industry-standard protocols:

As we saw in the example appraiser application, alert presence—which means an app has the ability to alert someone if you are available or not available to take his or her call—is only one capability of an application deployed using communication Web services in an SOA. Location, or the ability of an application to notify you wherever you are, and device, which defines how an application communicates, are other services signaled by SIP in a communications-enabled SOA environment.

Web services in an SOA environment also allow businesses to incorporate their business process' communications, such as telephony, audio/video conferencing, instant messaging, contact centers, voicemail, collaboration, and e-mail, into their mission-critical applications.

Developers' Tools
Enterprise application developers called on to create applications that invoke communications Web services as part of a process should expect nothing less than a full portfolio of component services, such as Voice-over-Internet Protocol (VoIP) capabilities and associated call control services. They should also have the tools at their disposal to make it all come together seamlessly.

Enter Avaya's Converged Application Enablement Services (AE) 3.0 platform, Dialog Designer, Communication Manager APIs, and Voice Portal.

Web services-based applications are hosted on AE and accessed over an IP network using a transfer protocol, such as HTTP. Avaya's AE Services platform, used in conjunction with the Avaya Communication Manager APIs, supports existing applications and provides the development environment for traditional software developers to create cutting-edge voice applications and business solutions. Here, you can access communication Web services that Web-enable applications for deployment in an SOA.

The Avaya Voice Portal is a Web services-based platform that delivers rapid services deployment for IP telephony applications. Voice Portal invokes Web services. It also includes Avaya's voice application development environment, Dialog Designer.

Built on the extensible architecture of the Eclipse 3.0 open source platform, Dialog Designer provides plug-ins to Eclipse that add speech recognition to voice applications via a framework of development tools. Dialog Designer stays true to its object-oriented design by offering modules that allow for efficient reuse of code by other applications.

SOA Advantages
Reuse: Speech capabilities developed for one application may be packaged as autonomous services and then shared, or reused, by many other applications, making reuse one of SOA's most endearing qualities for developers and companies alike. For example, consider an audio messaging service that converts text messages, such as e-mail, to VoiceXML. This service can be shared by many different applications that, e.g., offer hands-free interaction by converting text-to-speech. A voice browser embedded in each application synthesizes speech from the VoiceXML produced by the shared service.

Interoperability: A primary advantage of communications-enabled SOAs over traditional IVR and EAI systems is interoperability among the technologies required to implement them. Key to interoperability is the implementation of standardized protocols such as SIP and H.323. SIP is the standard for initiating, modifying, and terminating interactive user sessions that involve video, voice, and instant messaging, among other media types. SIP and H.323 are the leading signaling protocols for Voice-over-IP. Other standard protocols such as SOAP (the most popular messaging protocol for Web services), VoiceXML, and WSDL also help SOAs provide interoperability among all required technologies, thus taking away the vendor dependencies traditional IVR and EAI systems require.

Web Services: A key component and strategy of the SOA is Web services, which is a software system that supports interoperable, machine-to-machine communications over a network. WSDL is the XML format that describes Web services interfaces. Other systems interact with Web services using messages, which are enclosed in a SOAP envelope and transferred using Hypertext Transfer Protocol (HTTP) along with XML and other Web-related standards. Software applications can use Web services to exchange data over networks like the Internet, regardless of the language in which they were developed and the platforms on which they run.

With this architecture, business applications can embed voice capabilities such as call routing, call recording, and alert presence in business processes and applications, thus taking business applications to the next level. In doing so, people and processes are brought closer together in real time using the most appropriate medium, be it e-mail, instant messaging, or any other form of communications.

Avaya's implementation of its Web services-based SOA architecture utilizes existing IVR and enterprise applications through its use of Web services and standard protocols that provide for interoperability. As a result, your existing infrastructure need not be replaced, but merely extended to converge new, cutting-edge speech applications with business processes and enterprise applications such as CRM, ERP, and supply chain management systems.