Nebula [Firewall] - Prioritize VoIP traffic (Traffic Shaping / Bandwidth Management / Voice VLAN)

Sometimes it might be needed to set up your Nebula Firewall / Security Gateway in a way that VoIP-Traffic is being prioritized before other traffic. This can be the case if you have artifacts and interruptions during phone calls, or if the voice quality is very bad. The article below will show a few things to consider in this respect.

Traffic shaping/Management 

You can use the traffic shaping feature of the NSG in order to prioritize the traffic of the VoIP-clients. Navigate to 

Site-wide > Configure > Firewall > Routing

In the Create policy route / Traffic Shaping Rule, set respective entries by scaling the IP range you want to change the priority for. Use the priority field and enter respective numbers:

Separate Voice VLAN

It can sometimes be, that having your phone and data-clients in the same subnet will lead to heavy congestion of the network. However, having a static VLAN assignment might not be desirable or not even achievable - you need to have a separation based on if a phone or a PC is connected. Then you need Voice-VLAN!

You can configure Voice-VLAN on 

Site-wide > Configure > Switch > Switch Configuration> Voice VLAN

There is a priority dropdown list similar to QoS to allow users to prioritize voice packets on specified OUIs manually. User-configurable priority is from1(Lowest) to 6(Highest). In order to address your case, we recommend the priority is set to with Voice VLAN ID (eg: VLAN 2).

Then configure the uplink port(s) with PVID 2 and access type on 

Site-wide > Configure > Switch > Switch port(s)

You can tick multiple uplink port(s) simultaneously with the same  PVID and port-type setting. By doing so, the priority of the voice packet is higher than the data from the PC.