What Every UC Call Center Should Know About Session Border Controllers

The Call Center/Contact Center has been evolving since the first center in 1976 at Continental Airlines. Many things have changed over that 34-year period to where we are today with the migration to Voice over IP (VoIP). VoIP delivers significantly lower recurring costs and is a key enabler of contact center virtualization, allowing agents to work anywhere they have IP network access, including at home and while mobile. New Unified Communications capabilities help contact centers evolve, taking advantage of presence-enabled audio and videoconferencing, chat/instant messaging (IM), multimedia collaboration and communications-enabled business applications. Many contact centers are adding these services as integrated suites of UC applications.

But significant challenges in security, interoperability, service assurance and regulatory compliance emerge as contact centers begin migrating voice, conferencing and other real-time interactive services from TDM to IP networks.

To combat these challenges, call centers need to think about Session Border Controllers (SBCs). SBCs view all the end points, transactions and applications as individual unique sessions, making it easier to identify measure and track multiple UC touch points found in most call centers today. If you think of any call center or contact center, you need to think about how Unified Communications business process and applications all must work together in a graceful plane.

Consider how a Session Border Controller, or SBC, can make the following healthcare application a less rocky road to travel.

A pharmaceutical company wants to start delivering services to remote areas where there is no pharmacy but only a general store. A video kiosk is put in to the general store that allows customers to scan their prescriptions or ask for assistance, and a trained pharmacist joins the transaction via video conferencing from a remote call center many miles away. The remote pharmacist opens a session on the attached monitor, and begins a discussion with customer about their prescriptions, helps fill out paperwork, gets the customer's health care information and asks them to sign a virtual signature. He then asks if the customer requires any off-the-shelf products as part of the ship order to be delivered by courier tomorrow to the general store. Each conversation is recorded for metrics, service level agreements (SLAs), content accuracy, proper shipping information and any required credit card verification and validation of the transaction. The session is then concluded and a print out of the transaction with credit card information is delivered from the kiosk. One last twist, the call is then automatically transfer to an outside call center for credit card validation.

In a non-SIP world, this would have been a complicated transaction requiring many end points all talking to each other with several requirements for both voice and data transmission. Security would have been a significant issue as the infrastructure the client was using supported numerous interconnecting borders. The high cost of PRI's across each site added to the cost and complexity. The issues of inbound call routing and out bound load balancing, and the need for centralized routing table administration all added to the dilemma.

In a SIP world, this interaction is viewed as a number of unique logical sessions that require different levels of bandwidth using the SIP transport layer. In this case, the Session Border Controller would have been deployed by the contact center to enable the delivery of secure, high-quality, real-time interactive SIP communications, including VoIP and video conferencing. SBC's offer a number of key features that support the contact center deployment, including best practice routing, priority routing for E911 cases and more. Of particular interest in contact centers is the need for transfers from one center to another, which is generally an expense proposition. The SBC dynamically distinguishes the internal transfer and, using a feature called "Take Back and Transfer", keeps the call on the private network and can save the call center significant dollars. Another cost-saving capability of an SBC is its ability to save network bandwidth using codec renegotiation. Referring to our pharmacy kiosks example, the IVR required G.711 for speech recognition. Once the IVR processes the incoming call, the SBC renegotiates the bandwidth of the call to G.729, saving network bandwidth costs. Finally, the SBC can handle very complex call flows between telecom platforms, resolving interoperability challenges for both the IT folks and the end point users.

Most contact centers must record some or all of their calls for regulatory, quality management and/or training purposes. The IP trunking border provides an optimal point at which to replicate real-time communications sessions for delivery to a call recording system. Traditional IP call recording topologies perform session replication with port mirroring in a Layer 2 switch. This approach does not offer optimum reliability and consumes an additional ACD port for every session to be recorded. Performing session replication for call recording in the SBC offers two distinct advantages. One, it offers more reliable transport of replicated sessions to the call recording system than a Layer 2-based solution. Two, moving session replication to the trunk side of the ACD eliminates consumption of an extra ACD port for every recorded session; these costly ACD ports can thus be recovered for use as agent seats.

In North America, contact centers must comply with regulations for E911 services, which require that emergency calls be handled with appropriate priority. An SBC has the ability to identify emergency calls from anywhere within the virtual contact center, exempt them from admission control policies and route them with priority to the appropriate Public Safety Answering Point (PSAP).

Reaching home-based agents and small contact center pools over public internet connections demands a scalable, manageable NAT traversal solution that does not require remote users to reconfigure their internet access devices or use expensive VPN IP phones in their home. Depending upon industry and employee role, the privacy of sessions established across this border may be necessary for business reasons or compulsory for regulatory compliance, especially given the perceived higher risk of eavesdropping on the public Internet. However, homogeneous end-to-end encryption is not always feasible, as not all IP phones, media gateways or voice mail servers have the requisite encryption capabilities.

Products such as an Acme Packet SBC are ideally designed to handle large deployment of remote agents and can provide both NAT and security for contact centers looking to leverage the Internet. Acme Packet's Net-Net solutions provideinteroperability with the client's preferred service provider. Acme Packet SBC's Net-SAFE security features, policy-based routing and load balancing reduce the challenges contact centers have with regards to complexity, interoperability and expense of PRI's. Acme Packet's Emergency Session handling for E911 prioritizes and routes emergency/E911 sessions with enhanced QoS (3GPP E-CSCF) and Interfaces to external location servers (3GPP CLF)

A win-win situation for any call center or enterprise UC strategy.