One of the great promises of using VoIP throughout an enterprise is to reduce a company’s costs related to building, maintaining, and managing two separate infrastructures—one for voice, one for data. The downside for network operations personnel is the risks of migrating from a deterministic, always available, standalone voice utility to an IP-based voice service that shares networking resources with all corporate applications and thus is potentially fraught with performance and availability issues. While the networking team has been charged to deliver a more pervasive VoIP deployment, they are wary of doing so knowing that the end users will complain directly to them.

Here are some of the key areas of concern for networking personnel supporting VoIP services:

--Voice is a mission-critical application that suffers dramatically in the face of latency, jitter, and other common network maladies.

--End users expect high-quality service. When end users pick up the phone, they expect it to work — every time.

--Corporate IP data networks are known to be less available and much more dynamic than the traditional voice infrastructure.

--Element management systems are inadequate to manage a VoIP infrastructure, because they do not reflect the real-time nature of this communication. They also have no understanding of endpoints — VoIP servers, desktops, and devices — or the applications they consume.

No wonder Yankee Group (News - Alert) reports that 80 percent of enterprises have deployed VoIP, but only a meager six percent have done so throughout their enterprise (Yankee Group, US Economics of IP Communications Survey, May 2007).

Smartphones and Dual-Mode VoIP Devices

An increasing trend in sophisticated enterprises is the use of smartphones and other dual-mode devices that take advantage of wireless LAN (WLAN) connectivity to add mobility to VoIP. These devices pose yet even greater performance challenges to network operations personnel trying to maintain consistent service-level agreements and keep users happy and productive.

The challenge begins with the dynamic nature of dual-mode device mobility. When roaming, these devices are designed to automatically search for the best-performing network and will opt to attach to the corporate WLAN over the slower, more costly cellular broadband network. Yet when running off a WLAN, dual-mode device users must share 54 Mbps connectivity (the majority of networks are 802.11g) rather than take advantage of dedicated 100 Mbps bandwidth available from wireline switches. As a consequence, users are unaware that the WLAN they use daily can become susceptible to performance degradation issues.

Once attached to the WLAN, the dual-mode users can more easily take advantage of all the cool data features of their devices; that is, they will synch up with their contact databases, watch YouTube (News - Alert), or download a favorite video or TV programs. If there are numerous individuals on the WLAN engaged in similar bandwidth-hogging activity, performance will noticeably decline for any mission-critical applications being accessed on the same WLAN. Not only is this a blow to productivity; traditional trouble-shooting tools have tremendous difficulty locating the source of intermittent performance issues originating at corporate endpoints.

VoIP Challenges for Network Operations

Making VoIP “enterprise class” requires more than simply increasing the corporate network’s bandwidth capacity and defining strict QoS policies to guarantee success. Each IP phone, IP call manager, and IP voicemail system must be accounted for and its productivity continuously monitored to ensure that all are working properly.

There can be a variety of reasons why a VoIP phone doesn’t function as expected. It could very well be the device; but more likely, the problems stem from the overall VoIP ecosystem. For example, the shared internetworking infrastructure could be misconfigured; another end user can be downloading large files and consuming all the WAN bandwidth; or there could be a fundamental issue with one of the component applications, such as the call signaling or the RTP voice stream.

Details about these endpoints and applications, such as how they normally behave over the infrastructure and when they are adversely affected, is becoming mandatory information for identifying the complex problems that affect VoIP performance, as problems can originate from anything that is leveraging the same infrastructure. Knowing where to start in this complex web is the challenge for network operations and it can often take them days or weeks to locate and identify the target problem.

Rapid Problem Identification for VoIP

A new technology is now available to empower IT organizations to better understand their networks so that they can proactively detect and control problems associated with VoIP on the network infrastructure. Called rapid problem identification (RPI), this technology uses flow-based information and identity mapping to pinpoint endpoint and application problems in real-time and automatically alert IT personnel to take action.

RPI analyzes network flows from every IP endpoint — any device with an IP address — to establish individual, dynamic profiles for hundreds of thousands of endpoints and applications. It then leverages these profiles to identify any problems in actionable, organizational contexts.

For example, to detect problems with VoIP, the RPI technology analyzes the application behavior of all the IP phones, call managers, and voice mail systems deployed across the enterprise. This behavior analysis includes traditional performance variables like packet rate and bit rate, but also includes affinities to specific applications, periods of times and other endpoints.

The RPI solution takes a top-down approach to problem identification that provides an understanding of the application experience of the VoIP phone and how it differs from its normal state at the exact time that the calls began to drop. Was data traffic bursty? Did the VoIP phone stop emitting packets? The dropped calls provide symptoms of some core problem yet to be determined that are nonetheless affecting the end-user experience. If several IP phones started exhibiting a lower volume of traffic or a quick decline that lead to call failure, the RPI solution alerts IT personnel and identifies all IP endpoints experiencing symptoms.

Tracking VoIP Problems to the Source

The next step for RPI is to correlate and analyze all the VoIP phone-specific issues with other symptoms experienced on the infrastructure to determine a single specific problem source. First the technology groups symptoms into logical buckets to determine whether there are application commonalities in the symptoms. If a number of VoIP devices dropped calls, were all the endpoints the same phone type? Were they are on the same subnet? Did they share the same call manager? This correlation process is so granular that it even considers the operating system and configuration of endpoints. Using heuristic analysis, RPI can eliminate groups or symptoms that have little or no probability of pointing to the root cause.

Higher probability symptoms are then examined across the three dimensions of time, location, and application. In the vast majority of cases, this analysis points to a single problem source. Armed with this information, network operations personnel can determine exactly who “owns” the problem, and they can immediately escalate the issue to the right group for resolution. The result is actionable information about the source of the core problem that allows for a quick problem resolution to get the VoIP service up and running to normal quality levels.

Summary

VoIP offers enterprises tremendous potential in infrastructure capital expenses, but those advantages must be weighed against the operational burden of delivering enterprise-class voice service across an organization. RPI technology is the first troubleshooting alternative that gives network operations the complete picture of endpoint and application activity and performance and the only technology that can tie performance problems to a single core source in record time. By using rapid problem identification, IT organizations can get to the heart of complex problems that can affect real-time performance behavior and maintain mission-critical VoIP support throughout the enterprise.

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David Messina is Vice President of Marketing at Xangati (News - Alert). Xangati’s rapid problem identification technology is designed to enable IT organizations to be the first to respond to application and network performance problems and ensures high productivity across the enterprise. The privately held company is headquartered in Cupertino, California. For more information, visit the company website at www.xangati.com.