New VoIP Architecture Brings Benefits to Call Centers

By Christine J. Holley

“By 2006, some 35 percent of all annual North American call center sales will be made over IP networks.”– 2002 North American IP Contact Center Market Report, Frost & Sullivan.

With the creation of more robust, high-capacity IP (Internet protocol) networks and advancements in the adoption of global IP standards, the proposition of voice-over-IP in (VoIP) the contact center is increasingly attractive. Despite debate over the degree of resulting benefit, the general operational advantages of such converged networks are hard to deny. The benefits include reduced equipment and administrative costs, reduced call charges, and increased flexibility in service creation.

Converged communications model: While the migration from circuit-switched to IP-switched networks seems only a matter of time, there is confusion over architectural choices. To this day, most VoIP architectures are defined as the convergence of voice and data networks. While offering reduced costs and increased flexibility, this converged communications model has failed to provide contact centers with pre-integrated applications and with the type of built-in media control they require for critical functions. These functions include playing and recording audio for interactive voice response, automatic call distribution and unified messaging applications, conducting multi-party conferencing, analyzing calls and detecting call progress for outbound campaign management environments, using voice recognition for enhanced IVR (interactive voice response), ACD (automatic call distribution) or UM (unified messaging) capabilities, and enabling monitoring for ACD.

Without these functions, contact centers are forced to purchase additional servers or third-party solutions for media processing, increasing integration requirements and limiting options for using media processing. This lack of pre-integrated applications and built-in media control, combined with an architecture that is frequently no more open than traditional networks, has left many contact centers without a sufficient business case for VoIP migration.

Converged applications model: The newly emerging VoIP architecture promises to address the limitations of converged communications networks and give contact centers the justification they need to make the switch. Built around a unified server, this new converged applications model provides pre-integrated applications and media processing on the same server architecture to reduce the number of devices and integration points, allowing for a lower total cost of ownership. By centralizing media control, this architecture also provides a single interface for administration, customization, reporting and desktop control across different media types.

Since this model is based on an independent applications layer, it also enables contact centers to choose from a variety of platform vendors such as Cisco and Microsoft, and even incorporate emerging technology standards such as the session initiation protocol. This model provides contact centers with the means to establish hybrid architectures as well, composed of both circuit- and IP-based networks. Contact centers can use traditional switching methods for in-house communications, while taking advantage of IP-based cost savings for distributed and mobile employees. Migration from one network type to another can be accomplished without application redesign, protecting the initial investment.

Beyond these benefits are the breadth of applications this model offers compared to typical IP-PBXs and soft switches. These benefits cannot be underestimated. Many industry analysts estimate that reduced user and system features resulting from migration to VoIP can increase costs by as much as 50 percent of the initial technology investment. Must-have features range from basic telephony applications such as call forwarding and conferencing, to more sophisticated features such as screen-pop, skills-based routing, Internet text chat, and Web callback.

A final advantage offered by a converged applications model is an increased return on investment (ROI) proposition. Because this model emphasizes breadth and quality of applications – those that span both business user and agent functionality – contact centers are able to apply ROI across the entire enterprise. This results in a much higher value proposition.

Scalability: Scalability is of particular importance for multi-site contact centers where VoIP can provide some of the greatest benefits. One way that a converged applications model can maximize scalability is by offering spanned workgroup support. This enables workgroups on separate servers to be logically grouped together so that all universal queuing, reporting and real-time monitoring capabilities of single-server workgroups are preserved in the spanned workgroup. Since all interactions are logged in a common database – an important feature of the converged applications model – reports on spanned workgroup activities are easily generated.

For very large contact centers, a combined SIP (Session Initial Protocol) and spanned workgroup configuration can prove ideal. By provisioning a set of servers with T1/E1 interfaces to the traditional public switched telephone network, each server can receive calls for agents regardless of agent location or initial server association. Using spanned workgroups, calls can be routed to agents based solely on agent availability and skill-based matching. Supervisors can also be identified for a given workgroup for monitoring purposes. Just as with workgroup activity, this monitoring activity can also be logged and made available for easy reporting.

Reliability: Reliability within a converged applications model can be optimized through clustering. By clustering multiple servers in a spanned workgroup – which also increases scalability – calls based on pre-configured carrier routing rules can be more evenly distributed for improved load balancing and increased reliability.

As a result of their ability to grow and shrink based on the number of available servers, spanned workgroups in a clustered environment provide additional reliability by eliminating the impact of a single-server failure on overall system capacity.

Contact centers should also consider a disaster recovery plan for increased reliability. This involves a back-up server where, in the event of failure, calls can be manually switched from the main office to the disaster site. This is easily accomplished in an IP environment since IP phones are logically distributed on the IP network, so if a primary server or location disappears, the IP phones – either phones local to the server if only the server fails, or phones at remote locations if the entire main location goes off-line – can be easily re-routed to accept calls handled by a server at another location.

The Future: With some analysts predicting that IP-based telephony products will be the de facto architecture standard for all new shipments by 2005, the future of VoIP looks bright. Contact centers interested in migrating to VoIP, however, should take stock of their current infrastructure. If it’s characterized by disparate, proprietary servers, each running a different application and linked loosely together using middleware to make it all work, take heed. VoIP based on a converged communications model, while promising cost savings and simplified IT management, is not designed to resolve the challenges associated with deploying, maintaining, and customizing multi-channel applications across separate servers. It’s also not inherently designed to further the cause of open systems.

For this type of relief, contact centers need a converged applications model that enables them to flexibly incorporate VoIP into their infrastructure, while moving them further along the path of consolidated application processing and open systems.

Christine J. Holley is the Market Communications Director for Indianapolis-based Interactive Intelligence Inc. She can be reached at or (317) 715-8220. Interactive Intelligence can be reached at (317) 872-3000 or

[From Connection MagazineJune 2003]