Does provisioning have to be so painful?
The mind-boggling diversity of IP phones, soft clients, and PBX systems in enterprise environments represents both an opportunity for growth as well as a technical and operational challenge for service providers. Business customers are anxious to enter the world of VoIP, cloud-hosted PBXs, unified communications, and other productivity-boosting and cost-cutting alternatives to legacy voice systems. Service providers that can streamline VoIP services provisioning—and therefore reduce the cost of business services delivery—are positioned to grab the biggest market share and to reduce customer churn with rapid response to service requests.
So why has VoIP provisioning been so painful in the past, when both customers and service providers are so highly motivated to ramp up these services?
The just-mentioned diversity is the crux of the problem. Businesses want to protect their investments in legacy PBX and on-premise communications equipment. As a result, hundreds of different devices must be certified for interoperability with VoIP services. Traditionally, this burdened the service provider with manually evaluating and testing legacy as well as the latest new devices and their software upgrades as they became available.
Relief is on the way. The emergence of third-party Session Initiation Protocol (SIP) device certification labs offers service providers affordable alternatives to in-house testing. These certification programs essentially spread test infrastructure costs among many customers and are especially important for smaller service providers that cannot afford the big budgets required for in-house testing.
Certification does not solve all of the problems, however. The inherent flexibility and extensibility of the SIP signaling standard gives equipment manufacturers a great deal of latitude. As a result vendors have interpreted and implemented SIP specifications differently. There are unexpected behavioral, formatting and security differences in protocol implementations that can increase installation times and sap profitability for service providers.
Simplification at the edge
To resolve the signaling differences, service providers must provision an Enterprise Session Border Controller (ESBC) at each customer’s premise. The ESBC must carry out a broad range of protocol mediation actions to bridge the customer’s networks with the service provider’s VoIP service infrastructure.
The best-in-class ESBCs enable automated provisioning and also greatly simplify business services monitoring and management over a heterogeneous end-to-end VoIP infrastructure. This is due in part to designs that consolidate multiple edge devices into a single enterprise session border controller. An ESBC integrates several discrete components:
• WAN router and traffic management appliances
• Perimeter firewall device
• VoIP back-to-back User Agent (B2BUA) for protocol mediation
• NAT/DHCP server
• Discrete switches for voice call routing
• PSTN gateway appliance
• Call quality monitoring system
Highly integrated ESBCs replace these separately managed devices with the simplicity of an all-in-one solution. Session border controller functionality is no longer restricted to high capacity environments and the current generation of ESBCs can cost-effectively support service delivery to small and medium businesses as well.
Choosing the Right ESBC
As usual with any technology advancement, including deploying various business services, not all ESBCs are created equal. When evaluating a single-device VoIP edge solution, service providers must take into consideration features that maximize interoperability, security, quality of service and reliability. In particular, look for these differentiating features:
• Protocol mediation features that offer maximum flexibility—The ability to perform advanced SIP header manipulation is an absolute must to ensure connectivity between customer and service provider VoIP networks. Ideally, this capability is used to present a consistent SIP signaling interface to the service provider while hiding the differences in behavior, syntax or security configurations that exist in the customer VoIP network. Providing this consistent interface facilitates installation and troubleshooting, ultimately decreasing costs for the service provider and increasing the reliability of the service for the customer.
• Support for redundancy, survivability and an affordable backup connection—The world of VoIP services gives enterprises many new capabilities beyond traditional TDM or analog voice services. However, these new features are only as good as the customer’s ability to connect to them. A reliable service offering includes designs that support redundant network paths, redundant equipment and a fallback to basic local call switching in the event of a network or access link failure.
• Protocol-aware security—Leading-edge ESBCs implement an application-aware firewall function with VoIP media ports that are only opened when needed as well as the ability to restrict unauthorized devices from accessing VoIP services. VoIP-aware inspection can provide extra protection against communications-specific threats including eavesdropping, identity theft, denial- of-service attacks and toll fraud. ESBC devices should also implement authentication and encryption for customers with the most stringent compliance requirements.
• Traffic shaping and prioritization— Compared to data, voice traffic on an IP network requires special handling to avoid poor audio quality or dropped calls. ESBCs can ensure high quality voice services using traffic shaping, call admission control and prioritization. Prioritization must be available for both inbound and outbound traffic and should be easily adjusted in real time so that bandwidth can be allocated depending on the call volume. Advanced ESBCs can also notify network operators when voice traffic is exceeding the available bandwidth.
• Monitoring and troubleshooting tools— As a managed service, VoIP requires endto- end visibility. At the edge, an ESBC with an appropriate toolset included can help support engineers proactively identify and rapidly isolate issues on the customer site, at the gateway, or in the service provider’s network. Monitoring is particularly important for maintaining the health of the network and meeting service level agreements.
Lemonade from lemons
This overview of ESBC devices started with a major challenge faced by service providers: simplifying the provisioning and management of VoIP services. Looking back over the list of differentiating features for the ESBCs on the market today it is clear that a best-in-class ESBC is more than a band-aid for run-away OPEX. For example, security is a top priority for many businesses today and the increasing number of headlines about cyber-crime is a major concern. Service providers that choose an ESBC with compelling security features can differentiate their VoIP services with the value of added protection for communications traffic. Better monitoring tools supports a business continuity message for customers. Traffic shaping and adjustments avoid over-provisioning and demonstrate a resource-friendly solution.
The bottom-line, as usual, is all about cost-cutting. Business customers want to cut their costs by leveraging business services such as SIP trunking and Hosted PBX. An intelligent, highly integrated ESBC can mean the difference between a competitively priced VoIP portfolio or a high-overhead service that frustrates customers and burdens the service provider’s support staff. It makes sense to get it right at the edge and enable VoIP services delivery that is faster, easier, and ultimately higher value to today’s enterprise customers