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The beauty of IP telephony is that it turns voice into just another application on the data network. That means it can be integrated into other unified communications applications such as presence and chat to offer combined services. But IP telephony integration is challenging and requires that the IT organization understand how complicated unified communications and IP telephony protocols work together, as well as how to implement these combined processes throughout the organization.
The benefits of UC and IP telephony integration
IP telephony moves the traditional phone system from a siloed existence to become part of the enterprise data network. Beyond the obvious advantages, such as lowering the number of wires needed per desk and providing the kind of mobility that comes with connecting to the voice system anywhere on the wide area network (WAN), the opportunity exists to integrate voice with enterprise collaboration solutions.
"The key advantage to rolling IP telephony into applications and business processes is user productivity," noted Robert Arnold, senior analyst with Frost & Sullivan. "With a unified communications solution, users can not only see if their colleagues are available, but decide what the fastest method of communication with that person will be. A centralized communications suite consolidates all methods of communications under a single interface, minimizing the distractions to the end user."
IP telephony protocols create application links
IP telephony integration requires understanding a mix of UC and IP telephony protocols and interfaces to create the links between communication services and enterprise applications. While many standards exist to extend a unified communications solution into business and collaboration applications, these standards are adopted fairly loosely by most vendors, and compatibility between systems is not guaranteed.
The preeminent protocol that serves as the glue to hold IP telephony together is session initiation protocol (SIP). SIP connects desk phones to the call control servers, links remote sites via gateways into the centralized IP telephony system, and is quickly becoming the interface to telecommunication services from carriers. SIP also enables softphones and computer applications to act as phone client to the IP telephony system. With a headset, an end user's computer can serve as the interface to the voice system and provide a dialer interface for other applications.
An extension to SIP, SIMPLE (SIP for Instant Messaging and Presence Leveraging Extensions), broadens the capabilities of SIP beyond voice, rolling instant messaging, Web conferencing and presence technologies into the standard. Alternatively, IP telephony vendors may opt to support XMPP (Extensible Messaging and Presence Protocol) to provide similar IM and presence functionality. Based on the open source Jabber protocol, XMPP leverages Extensible Markup Language (XML) to facilitate these services. Google Talk, a free chat service, uses XMPP to allow text, audio and video chat between users. Another application of XML is VXML (Voice XML), which adds interactive voice response (IVR) capabilities to the XML standard.
For further integration with the IP telephony solution beyond the multimedia capabilities and presence, most vendors offer a combination of XML messaging capabilities, as well as their own custom application interfaces (APIs). Both approaches allow developers to interact with the IP telephony solution from within their own applications. Then, in most cases, the application can simply request the type of communication link it needs, leaving the IP telephony system to determine how best to facilitate that request.
Enterprises seeking to integrate IP telephony will need to take stock of the various applications in use within their organizations and work closely with the vendors to ensure that the systems can actually be stitched together.
UC and IP telephony integration: Weighing the cost
Whether because of these not-so-compatible standards or an enterprise's reliance on unique software for its operations, making the components of an enterprise network work together can prove to be expensive.
"In most cases, an implementation of IP telephony integration requires a custom project, invariably raising the costs, calling into question the perceived benefits," said Brian Riggs, research director for enterprise communications at Current Analysis.
While many IP telephony vendors are working to offer boilerplate integration solutions to take some of the pain and cost out of IP telephony integration, it is ultimately up to enterprises to weigh the benefits of IP telephony application integration against the costs of undertaking deployment.
There is also the human factor in the success or failure of an IP telephony integration project. For a unified communications solution to be adopted and embraced within an organization, end users will have to see the overall benefit of the technology and understand how it will improve their day-to-day workflow. It can be costly to train end users in a way that proves this point.
"IP telephony integration can be a source of disruption. End users are used to the current communications processes, even if that process is less than optimal," Frost & Sullivan's Arnold said. "Understanding this disruption and helping users manage the change will be a necessary component of any project."