The myths of VoIP deployments: there are a number of common pitfalls to avoid to help assure the success of your project.
Myth one is that VoIP is just another data application. The concept of VoIP is so simple that organizations often underestimate just how complex the reality of VoIP is. Delivering a consistent, high-quality user experience presents a host of challenges.
Myth two is that voice quality is not an issue, since there is plenty of bandwidth. Achieving excellent voice quality, however, requires more than flipping a switch or setting the knobs on your network correctly. In the end, the user's perception of voice quality is all that matters, and the user's experience depends on a range of factors, including a network that can be complicated to engineer and difficult to troubleshoot, and which requires regular maintenance.
Myth three says that all VoIP phones are created equal. With IP telephony, calls are not limited to traditional telephone devices; users can take advantage of soft phones, personal digital assistants and wireless devices, as well as traditional phones. The characteristics of the phone and the application matter as much as the health of the network--a cheap phone on a clean network can sound worse than a high-quality phone on a poor network. Successful VoIP deployments require a systems view that takes infrastructure, applications and instruments into account.
VoIP is still an emerging technology, so there are new standards, moving feature sets and competing approaches, which make interoperability a major challenge. Voice is a difficult medium for IP: it is sensitive to the inherent characteristics of IP networks, including latency, jitter and packet loss. Voice quality, availability and security are critical, but are difficult to measure and manage. Yet, expectations are high: five 9s availability, toll quality, clean interoperability and applications, and dial tone even when the lights go out.
All this occurs in newly converged IT teams, where neither the "voice people" nor the "data people" have worked with anything quite like it before. Anyone who has successfully deployed VoIP and IP telephony applications will readily admit that the process is a "learning experience" and that delivering the promised benefits of VoIP is often a challenge.
PITFALLS OF VOIP DEPLOYMENT
The fact that VoIP is a new technology, requiring new organizational structures, and operating at several "layers" simultaneously makes each deployment project a challenge. While each project will have specific issues, there are a number of common pitfalls you can avoid to help assure the success of your own deployment.
Lack of organizational readiness. VoIP is a new technology for the data and voice teams in any IT organization, and successful deployment requires skill and commitment from both groups. In order to be successful, however, good cooperation and clear lines of responsibility must be in place.
Underestimating VoIP as "just another application on the network." Although awareness of the special place of voice and IP telephony is now widespread in IT departments, it is still all too common to launch into a deployment under-prepared. Unlike most IP applications, voice and video applications are sensitive to delay, jitter and packet loss, so quality of service must be implemented in most networks to achieve acceptable call quality. In addition, the expectations for voice availability across the enterprise are far higher than for most other applications. A useful technique is to provide cross training, case studies and the necessary tools for the staff involved with a deployment.
Expecting telephony-grade support from your vendor. IP telephony vendors may have a business model and philosophy for voice that does not align with the expectations of a typical IT department. Telephony services are run on standard servers, so identifying who is responsible for what can be less clear than it is with legacy PBXs. Compounding the problem is that many enterprises use different vendors for different parts of their infrastructure. Preparing ahead for troubleshooting and system management can help to avoid the finger pointing and delays in problem resolution that often occur.
Depending on a one-time network assessment. Though useful, a network audit cannot discover the dynamic behavior of a complex network. As a result, multiphase deployments often have trouble in later phases be cause conditions have changed since the initial assessment. Testing a network with actual VoIP traffic on a regular basis can avoid ongoing headaches-many of which are caused by misconfigurations that are a side effect of some other project.
Lack of a "lifecycle" view. A classic scenario is to neglect troubleshooting until after deployment; another is to neglect the proper testing to extrapolate from a pilot to a full-scale deployment. Viewing deployment as a set of concrete phases helps ensure clean deployments and management.
Focusing solely on infrastructure rather than applications. In a recent survey, the majority of VoIP deployments were motivated by applications such as messaging, contact centers, and telework rather than by a less expensive or more manageable infrastructure. There are three levels at play in every VoIP deployment: packet level, call level, and application level. The most successful deployments pay attention to all three layers throughout the lifecycle.
Although avoiding these common pitfalls--and assuring the interdependent planning and testing required--may seem daunting, having a clean deployment and realizing significant business benefits are possible. The key is to seek out best practices and equip your teams with the best available knowledge, methodologies and tools.
VOICE QUALITY ASSESSMENT
Ensuring voice quality is the challenge most frequently cited by those deploying and managing enterprise VoIP environments. Quality depends on the characteristics of the phones, equipment and incoming signal, since echo, distortion and noise matter as much as packet-level impairments. Arming yourself with measurement and troubleshooting tools is important if you hope to resolve user complaints.
The second quality challenge is ensuring that new applications perform smoothly on the VoIP infrastructure. Voice applications--such as conferencing, messaging and voice mail--are what typically provides value from IP telephony. These applications tend to have a large number of potential paths and many configuration parameters, and there is an additional twist: the way these applications interact with a new infrastructure can change their effectiveness. Changes in traffic or configuration can impact the interactions between the infrastructure and applications.
For example, both speech-recognition software and VoIP rely on voice-activity detection. Voice-recognition software applies a recognition algorithm when the speaker stops talking, and a VoIP gateway uses an almost identical algorithm to determine when to send a packet. If a VoIP gateway or other VoIP equipment is too aggressive about deciding when a speaker has stopped talking, then speech recognition cannot work well. The voice quality will be high and the voice quality score will be good, but the speech recognition functionality will be ineffective.
A third quality challenge is the ability to troubleshoot. Unlike a traditional phone system, where you can easily pull a wire or check a connection, enterprise VoIP depends on many "moving parts," making troubleshooting and resolving VoIP problems, especially intermittent ones, difficult. VoIP-specific tools and testing play major roles, both for isolating and recreating problems and for determining how critical they are through regular benchmarking.
With a proactive, lifecycle approach to testing and management, your organization can:
* determine how much VoIP traffic the network can handle without degrading voice quality;
* find configuration and interoperability errors in networks and VoIP equipment;
* detect and troubleshoot interoperability issues;
* find performance bottlenecks and resource problems;
* trap and troubleshoot difficult and intermittent problems impacting application functionality and voice quality;
* tune speech applications for best performance; and
* ensure that service provided by offshore or outsourced facilities is as good or better as locally provided service.
A range of test and troubleshooting tools designed specifically to ensure the success of VoIP deployments are available. An analyzer, for example, can trace and troubleshoot VoIP at the call level by visualizing signaling and voice-quality problems. Automated testing and troubleshooting solutions can deliver fault diagnosis and isolation, voice-quality assessment, and application functionality and performance testing.
For more information from Empirix: www.rsleads.com/507cn-262
Drivers for VoIP Implementations General 85% Telephony Messaging 58% Remote/ 51% Teleworkers Toll 46% Bypass Call Routing/ 45% CTI Other <1% N=177 Multiple responses allowed Source: Empirex, Inc. Note: Table made from bar graph. Top Concerns about VoIP Implementations Other 12% Upgrade 8% Procedures Security 25% Interoperability 8% Voice Quality 47% Source: Empirex, Inc. Note: Table made from pie chart.
Jeff Fried is CTO of the enterprise solutions group at Empirix, Bedford, Mass.
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|Title Annotation:||Voice Networks|
|Date:||Jul 1, 2005|
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