Reliability and performance testing is the only way to guarantee quality of service

If you want a successful IP network, test it before, during and after implementation

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If you want a successful IP network, test it before, during and after implementation




Any business planning to implement or improve an IP network without testing all potential scenarios is sure to create a network territory where users fear to tread.

The ultimate test lies in being able to set up and run an IP network that delivers a delay-free, high-quality service to users.

Although some enterprises expect to ensure a high quality of service across the network by throwing bandwidth at the problem, this is expensive and inefficient. They would be better off taking a phased approach to equipment and network testing, service validation, and ongoing performance, reliability and service assurance.

Trust in the network hardware is crucial. It is vital that the equipment that is going to be implemented has been tested thoroughly before it comes anywhere near the organisation. That may sound obvious, but all too often equipment is tested in the lab with little regard to what might happen in the real world.

IT departments also need to be able to guarantee the requirements of various applications and services and ensure that their networks are ready to support them. This means that pre-deployment testing needs to be tailored to individual business requirements.

Active tests to review how a network would behave under different conditions should give a good idea of how the kit will react in the working environment. For example, how will it cope with heavy data loads or what will security performance be like under denial of service attacks? By recreating real-world conditions in the lab, you can see what the quality, reliability and throughput will be like, thereby ensuring that the network will provide the level of service required by the business.

However, lab-based trials are just the first step in preparing for a new or improved IP network. Although this type of testing will identify a large percentage of problems, live networks often bring with them unexpected difficulties which cannot be identified in the lab. Once a network goes live, it is in a constantly changing environment. New users and access devices come online, technicians reconfigure and misconfigure equipment and traffic patterns change by the week, the day, the hour or even the minute. This is where we need to start looking at performance and quality of service issues.

Quality of service should embrace bandwidth allocation, prioritisation and control over network latency for network applications, but this can only be done when a network is operating at full capacity to ensure that data traffic can cope with the mixture of data and real-time applications. This is also the only way to avoid bottlenecks and congestion, which can be caused by sudden bursts of traffic and can hit various parts of the network, including the internet gateway, switches or even heavy voice traffic.

In some cases, problems pass users by. They may tolerate sluggish e-mail transmission, slow file downloads and patchy internet browsing, but they are unlikely to be forgiving if direct communication links such as voice or video conference calls are erratic or of poor quality. A half-second delay on a link delivering voice will cause the user to hang up in frustration, and rightly so.

Testing of network performance and reliability must be continuous. And it is vital that enterprises can identify possible anomalies and plan for worst-case scenarios so that disruption is kept to a minimum. Test equipment experts can provide the right tools to do the job and also the methodology to ensure that the correct procedures are followed. The result will be a high performance, reliable network.

So, you have tested before you implement, you have the tools in place to assess performance now the network has gone live, but what do you do if problems do arise? As more IP networks are deployed, there is a growing pressure on enterprises to recruit and retain the correct level of engineers to diagnose and resolve network problems. However, with demand for skills high, maintaining the correct staffing levels can be a problem.

Using test and diagnostic tools that are simple enough for less skilled engineers is helping many businesses overcome staff shortages. They can gain considerably by equipping less skilled network engineers with automated test and diagnostic tools. This gives them the ability to fix basic network problems without having to escalate the problem to technicians, who may be in short supply.

So the road to high performance IP networks is long and winding but one thing is certain: sound testing and fast diagnosis is crucial to rolling out and maintaining high quality, reliable networks. Undertaking their own testing and monitoring can help large enterprises looking to cut the operational costs associated with implementing and maintaining corporate networks based on IP, as well as reducing the risk of major failures.

Mark Orchart is director of European marketing at Spirent Communications

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