As voice over IP (VoIP) traffic has migrated onto many data networks in financial services, manufacturing, retail, healthcare and other organizations worldwide, problems have emerged and been addressed in a variety of ways. Frequently, network administrators are unaware of problems until end-users’ complaints alert the IT staff of troubles with voice quality or system performance. Often, small problems that go unreported or unchecked grow in size and impact over time until many users are affected, business is impacted and revenue is lost.

The importance of voice in any enterprise network and its latency-intolerant nature makes discovering problems in the earliest stages essential. Staying ahead of such problems means developing an aggressive strategy to identify performance problems, pinpoint the root causes and remediate VoIP-affecting issues. The following questions can help lead to an effective management process for VoIP problems:

Is there a problem in the network?
What is the root cause of the problem?
Has the issue been resolved?
How is the network growing and changing?

Detecting problems on the network is the first step. Continuous monitoring of networked application traffic flows for trending, alarming and analytical evidence will produce key performance indicators. Immediate notification of link or application utilization increases can pinpoint a congestion problem before it impacts the VoIP traffic. New applications added to the network should be identified to determine if the network can handle the additional load without degrading voice traffic or other applications.

Metrics on VoIP quality indicators like jitter, packet loss or mean opinion scores should be monitored in order to locate network degradations before users notice quality issues. Access to this information in real-time, as well as trended in historical reports, will help to quickly ascertain if a problem is emerging and will enable all appropriate personnel to collaborate on the next phases–diagnosis and possible corrective actions.

Diagnosing the cause of the problem is the second step. IT organizations should start their diagnostic analysis by asking, “What are the symptoms of the network or application problem?” Following a top-down approach to troubleshooting the issue, begin with analyzing the applications in use, the conversations between end-user IP addresses and data center application servers, the volume and utilization of these applications and conversations, as well as other resources vying for the same bandwidth.

Analysis in real time or over time will reveal all applications, both inbound and outbound, within assigned auzlity-of-service classes, uncovering possible misconfigurations that might be causing VoIP quality problems. Applications traversing the enterprise network can encounter unsecure or unapproved traffic, such as viruses or streaming Internet radio, that might delay VoIP call connections.

Diagnosis also can involve sophisticated bounce charts, decode filters and playback analysis based on a continuous stream of recorded packets to troubleshoot the most persistent, complex problems affecting business applications, VoIP traffic and call setup protocols.

Asking IT to run a converged network without this information is like trying to navigate a foreign city without a map–resulting in many guesses and wrong turns, wasting valuable time. Proper diagnosis depends on rich application and conversation-flow visibility and, when necessary, the actual packet evidence for in-depth forensics analysis.

Step three involves determining that a proper diagnosis has been made, devising a corrective action plan and confirming that the problem has been corrected. This step may take some time, first to determine the corrective action and then to implement and verify it. Alternatives may include adding bandwidth, correcting misconfigurations or working with a third-party application developer to improve the architecture of a poorly written, chatty application.

The performance management system will confirm if the actions taken have returned response times for key business applications to within acceptable levels; improved VoIP quality of experience metrics; and restored application and conversation levels to within previous baselines.

The widespread launch and subsequent rollout of VoIP marks the start of ongoing management, so the fourth step is to continue the detection and diagnostic activities to maintain a positive performance and user quality of experience across the overall VoIP deployment. Broad elements of ongoing management include:

warnings of potential problems before they have the chance to have a noticeable or negative impact on user experience;
access to real-time data for troubleshooting issues as they emerge;
analysis and historical reports of trends for planning and traffic engineering;
in-depth application visibility to recognize voice and application degradations, bandwidth contention issues, traffic-engineering changes or voice-disrupting traffic.

Good network and application performance depends on a structured approach throughout the performance management of a problem’s lifecycle. Using an integrated VoIP and business application performance-management solution to detect, diagnose, verify and manage the projects and problems that may arise in the future is just one more way to reduce MTTR and help maintain a high level of VoIP quality and service to the enterprise’s end-users.

Eileen Haggerty is director of solutions marketing at Netscout Systems, Westford, Mass.

For more information (click here)