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John Scarborough: As you prepare your network for your new IP5280 VoIP services, there will be a few items to take into consideration while planning your implementation. Your old copper phone lines are no longer in use and all of your voice traffic is now traveling across your local area network as data just like in e-mail. There is however one critical difference to be aware of. Your voice traffic is happening in real time. This means that minor glitches and delays that you would normally never notice could have a negative impact on your call quality.

Here are a few steps that you can take to ensure that your network is optimized for voice traffic prior to your installation. The first item that we will cover are firewalls. Generally speaking, you don’t want your voice traffic passing through your firewall. The purpose of a firewall is to protect your network from fraudulent traffic and ensuring the security of your data. It does so by inspecting all of the data flowing through the device, rejecting unauthorized sources and allows your valid traffic to pass through to your network. Voice traffic however, as we covered before, is happening in real time and this constant flow of data can put an unnecessary strain on your firewall as well as potentially introducing latency and affecting your call quality.

If your network design requires that your voice traffic route through your firewall, you will first want to verify that your device is SIP-aware and has a capacity to handle your new IP5280 Voice over IP system. The next item that we’ll address is network design. At a higher lever, there are two basic set-ups that you can deploy. The first option is a converged design with your data and voice traffic running through the same network. This is achieved by utilizing the switch port built into the back of your Polycom phone, eliminating the need for multiple Ethernet drops and simplifying the installation.

The second option is the separation of your voice and data traffic. This can be achieved through a physical separation with separate Ethernet drops and switch hardware for phones and data or could also be a logical separation such as with virtual LANs. If you’re pushing lots of data across your network or deploying a large number of phones, this will help to ensure the best possible quality for your new IP5280 phone system.

The final item that we will cover is quality of service or QOS. In a nutshell, this means giving your voice traffic top priority and making sure that there is always enough bandwidth available for high quality voice communications. Without QOS, a large download on one user’s PC could impact the quality of another user’s phone conversation. With QOS in place, phone traffic is given top priority. The bandwidth available for your download will be temporarily reduced to ensure that the required bandwidth for your VoIP call is available and call quality is unaffected.