Voice deployments have produced a number of issues to be considered, and now there are a variety of tools available and designed to troubleshoot and monitor VoIP services. Careful consideration needs to be given to the specific type of tool needed for the type of application that you are considering.
Pre–deployment
Many network managers are concerned of the affect putting VoIP onto their networks will have on existing services. There is also a question of what level of VoIP service their existing networks will be able to support.
Tools such as Visual Planner, Assessor and NetVoyant can put synthetic calls across a network and measure the performance impact they will have and the call quality that can be achieved by different codec’s etc, prior to the actual roll-out.
The Assessor solution also audits the hardware in the network for its performance levels and suitability to support VoIP technology.
Troubleshooting
Once in place there will be questions regarding the performance and quality of VoIP calls.
Packet analyser solutions such as Observer and Protocol Expert have specific screens for splitting out the different parts of the call, the performance etc. These can also calculate MoS scores. In the higher end Fluke products (INA) this VoIP capability has been imported into the tool to make it more flexible.
Some of the less sophisticated tools such as the Nettool and Etherscope also provide a degree of diagnostic information, such as the call set ups, which is sufficient for first-line support and identification purposes.
Monitoring
Once the VoIP service is running, monitoring the consistency of the service needs a long term monitoring solution. The NetVoyant solution polls synthetic calls between devices in the network and records the networks ability to support VoIP calls, as does the ShoreTel System Management System (ShoreWare Director), also while looking at the real-time call performance activity.
Netflow solutions such as Crannog NetFlow Tracker or ReporterAnalyser can tell you how much bandwidth VoIP is taking on key network links.
Visual Networks have a dedicated VoIP solution that works in a similar way to the Fluke Reporter Analyser, but also records the MoS scores for delivered calls. This means that it analyses where quality was lost and records the calls made on each link and provides fine detail on those specific problem calls.
Last Updated: 02/08/2007