What VoIP Readiness Assessment Does Not Tell You

In the previous posts I had covered many obvious business reasons driving business VoIP adoption in the enterprise including costs savings, productivity increases, and image benefits. These benefits are typically enabled by VoIP infrastructure on a converged network, but achieved through IP telephony applications such as messaging, conferencing and geographic independence.

Realizing VoIP Hosted PBX benefits can be a challenge, and organizations may experience frustration, stress and even despair as they work to deploy it in their environments. Generally speaking, VoIP is much more than just another application on the network, and most organizations have never managed an application with high availability and performance requirements like those of VoIP.

The only real way to ensure lasting trouble free voice quality in an enterprise VoIP Hosted PBX deployment is through proper management of all of the devices within network path between the endpoint device (be it a handset, computer or a softphone) and a VoIP Hosted PBX service provider system.

Hit or Miss Approach

Unfortunately, experience shows that for various reasons most implementations are not carried out that way. The trouble with this approach is that Voice Over IP technology is extremely lenient in terms of what is allowed and what may or may not work. In fact, in many cases organizations, (especially small), may actually get away with having an unmanaged network path, loosely managed local area network and no SLAs or network QoS whatsoever. This creates a minefield in perception of a VoIP Hosted PBX technology because the results of such implementation could vary across the entire range of quality and time spectrums. Even if such implementations work at the time when they are deployed, there is no guarantee or evidence that they will continue to work when network utilization patterns change.

The concept of VoIP is so simple that it’s common to underestimate just how complex the reality of VoIP is. VoIP is a technology of new standards, moving feature sets, and competing approaches, which makes interoperability a major challenge. Voice is a tricky medium for IP: it is very sensitive to the inherent characteristics of IP networks, including latency, jitter, and packet loss. Voice quality, availability, and security are critical, but they are difficult to measure and manage. (Quality also depends heavily on the characteristics of the phones, equipment and the incoming signal, since echo, distortion, and noise matter as much as packet-level impairments). Yet the expectations are high: five ‘9’s availability, toll quality, clean interoperability and applications, and dial tone even when the lights go out. Most companies have never managed an application with such high availability and performance requirements.

Provisioning and Maintenance Vows

When problems arise, however, many businesses are quick to place the blame for voice quality troubles with the Hosted PBX service provider often neglecting their role in management of the network path or even understanding that they have such responsibility.

Many VoIP service providers, who took the brunt of blame for poor call performance, are now recommending network VoIP readiness assessments even before they will sell or service the IP PBX and phone systems. While this may be a step in the right direction, many enterprises are falling into three common pitfalls when it comes to assessments.

  • Snapshot Approach

A one-time assessment provides analysis for that point in time. However, networks and applications are extremely dynamic, so what may be true today is irrelevant two months from now when deployment actually occurs.

  • Simulated VoIP Calls Are Not Enough

Many groups are using simulated calls exclusively to test readiness. While this approach gives some visibility into voice performance, it provides little view into how the voice and data applications are impacting each other on the shared infrastructure.

With simulated testing, an appliance or software agent generates “fake” VoIP calls and measures the performance across the network. This approach can provide detail like MOS, R factor, jitter, packet loss, or delay for each call. If the call performance is above acceptable, then the network is deemed ready. If the performance is below quality metrics, then changes in the infrastructure should occur before deployment.

The pros associated with this approach are focused on the ease of deployment with quantifiable metrics. This approach is typically the easiest to deploy.

The cons associated with just synthetic calls include not understanding how the VoIP traffic impacts data and vice versa. In addition, while the metrics include criteria, such as delay, synthetic transactions cannot pinpoint what is causing issues such as delay. For example, is it the local loop, usage, carrier performance, or class of service (CoS) settings?

  • Focus on the VoIP Readiness Assessment and Ignore Post-deployment Management

Assessments tend to help only with evaluating readiness. Enterprises are spending several thousand dollars per site for this, but they do not have a plan for ongoing management after VoIP has been deployed.

Cost vs. Guarantee Business Dillema

For those who have successfully deployed VoIP and IP telephony applications, the process is generally a learning experience. Though each project has specific issues, there are a number of common pitfalls:

  • Lack of organizational readiness
  • Underestimating VoIP as just another application on the network
  • Expecting telephony-grade performance without benchmarking
  • Depending on a single-shot network assessment
  • Lack of a lifecycle view
  • Focus on infrastructure only rather than applications

Though lots of interdependent, daunting and sometimes costly planning and testing may be required to guarantee VoIP service quality, it is quite possible to have a clean deployment and realize significant business benefits. It is important to understand that there is no complete process available today. I.T. professionals tasked with VoIP implementation should seek out the best practices available, and to equip themselves with the best available knowledge and tools.

Measurement is crucial for improvement; it’s an old adage that you can’t manage what you can’t measure. At any stage in deployment, it is important to capture baselines and to have the capability to measure at multiple levels. The following table shows some important measurements and some tools offering a view of the levels involved in a VoIP deployment.

VoIP Quality Layers

Packet Layer

Call Layer

Application Layer

  • Packet Loss
  • Jitter Delay
  • Call Completion Rates
  • Latency
  • Voice Quality
  • Mean Opinion Score(MOS)
  • Application Completion Rates
  • Cross-Platform Interoperability
  • Service Provider SLAs

Layer Management Tools

  • Packet Analyzers
  • Element-Level Network Management
  • Switch/Router Console/statistics
  • Call and Protocol Analyzers
  • Infrastructure Testers
  • Application Path Testers
  • Transaction-Level Log Analysis
  • SLA Management

The point: In order to guarantee voice quality performance in today’s converged world of Hosted VoIP, there needs to be continued on-going visibility of both voice and data to see and understand how they interact. Such guarantee comes at a cost and business decisions on whether such guarantee is justified should be made by organizations based on factors such as budget, executive’s understanding of VoIP technology, and business tolerance to voice quality-related issues.