The quality of VoIP phone calls through a firewall often suffers when the firewall is busy and the bandwidth available for VoIP traffic fluctuates. This can be lead to unpredictable results and caller frustration. This example describes how to add traffic shaping to your FortiGate to ensure enough bandwidth for VoIP traffic regardless of other activities on the network.
To achieve high-quality real-time voice transmissions, VoIP traffic requires priority over other types of traffic, minimal packet loss, and jitter buffers. You can limit bandwidth consuming services, like FTP, while providing a consistent bandwidth for day-to-day email and web-based traffic. First, you customize three existing traffic shaper profiles—high priority, medium priority, and low priority—and then create a separate traffic shaping policy for each service type.