February 2005

Testing Is Fundamental

BY MARC ROBINS

No doubt about it, the enterprise market for IP telephony gear is on a tear. According to market watchers such as Synergy Research, IP PBX equipment revenues are expected to approach the $10 billion mark this year. And 2005 is also expected to herald a major milestone for this equipment sector, when revenues should surpass those of traditional TDM-based PBXs.

As the spread of IP telephony and converged networks into the enterprise is opening the door wide to an array of new enhanced applications and services, as well as dramatic cost savings and productivity increases, the growth of converged networks is also bringing with it a unique set of challenges.

New converged networks will need to serve “double duty” when they begin to support real-time voice (and possibly “triple duty” with new video applications), whether an enterprise is converting to a pure IP solution or making due with legacy equipment and a gateway. Such new demands can quickly overwhelm these networks if proper planning and testing isn’t conducted prior to deployment.

If personnel tasked with network management fail to ensure that the network and equipment are up to the new tasks at hand, more and more companies will start running the risk of experiencing an array of quality of service (QoS) issues. These QoS issues can result in an unacceptable degradation of voice and video traffic quality, and include packet loss, excessive latency levels, jitter, clipping, and excessive levels of echo. Indeed, an untested IP telephony deployment is simply asking for trouble, as these QoS issues can seriously impact the quality of corporate communications at minimum, and lead to complete network failure in the worst-case scenario.

Essential Predeployment Considerations
In order to get the most out the new IP telephony gear on the market, and to avoid the risk of communications disruption and network failure, there are a number of essential considerations one must make before choosing and deploying a new enterprise IP telephony solution.

1. Get a Handle on Network Performance. What is the network currently capable of? What loads and traffic types can be placed on it before performance is impacted?
2. Understand the Level of Interoperability. Are data and voice equipment interoperable with each other, as well as any legacy equipment kept in the mix?
3. Determine the Impact of Security Equipment. Firewalls and other network security equipment can seriously affect the quality of voice and video traffic by introducing additional jitter and latency, and in some cases make effective communications impossible.
4. Determine the Impact of Software Upgrades and New Hardware. When making changes within the network, what is the impact these changes will have on network performance?
5. Assess Real-World Performance Versus Vendor Representations. Many vendors make claims such as “guaranteed interoperability” with Product Type A or guarantees regarding load capacity or scalability. But what happens when products are deployed in the real world?
6. Right Size the Equipment Investment. What is the amount of equipment and the scalability you will require? Having a certain amount of foresight is a requirement as you begin the migration.

Testing Is Fundamental
Comprehensive lab testing, or at the very least pre-deployment testing, is increasingly viewed as the most reliable way to ensure a converged network will operate successfully in its new configuration. A number of companies, including Spirent Communications (www.spirentcom.com), offer innovative testing solutions to address this increasingly important market requirement.

Spirent’s recently introduced Abacus 5000 IP Telephony Migration Test System combines IP telephony and PSTN testing in a single platform. This solution offers real-time call statistics and protocol analyzers for identifying all types of QoS issues. The system works by generating real voice streams and simulating enterprise traffic loads for an accurate analysis of voice quality impact. It also offers the ability to test interoperability of a number of devices and switching schemes, including analog, TDM and VoIP traffic. The call generation feature supports a number of popular IP telephony protocols, including SIP, H.323, Megaco/H.248, MGCP, and RTP.

On the service front, Spirent has started to offer a new integrated IP Telephony Assessment Service for companies that recognize the need to perform network testing, but don’t want to incur the additional cost of purchasing a testing system. The Spirent IP Telephony Assessment Service is designed to provide analysis of both IP and PSTN networks in separate and converged configurations. First, a complete assessment is conducted of a company’s requirements in terms of desired applications and scalability, as well as the type of network and services being implemented. Then a customized network analysis follows, which includes voice quality assessment and connectivity analysis based on location. A summary report is then provided that features detailed call quality statistics and charts, as well as problem identification for additional testing. Follow-up testing can address specific QoS problems like latency and jitter.

Marc Robins is Chief Evangelism Officer of Robins Consulting Group, which offers an array of services to the IP telephony industry. He has been involved in the telecommunications industry as a reporter and analyst, trade show producer and publisher, and marketing executive and consultant for more than 24 years. For more information, call RCG at 718-548-7245 or e-mail [email protected].

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