Layer 3 switching with AoIP, unstable audio flows but way below SG-1100 bit rate limits.

[andrewK]

I have a SG-1100 with 3 VLANs configured on the LAN interface. These VLANs have a few AoIP appliances on them managed by a server (Dante Domain Manager) that handles the unicast PTP between subnets so that the devices may keep sync and share audio across subnets.

PfSense is providing DHCP and BIND DNS to hosts.

This is in a minimized lab environment for proof-of-concept for now.

Downstream of the LAN interface of pfSense is a Cisco SG-350 that is providing the VLAN breakout via trunk port to the pfSense SG-1100.

I have two options for providing the layer 3 switching:
1- Netgate SG-1100 for routing.
2- direct gateway traffic to the Cisco SG-350 for routing.

I would love to use pfSense for the layer 3 switching however when I do so I get some instabilities that I can't figure out. Audio will intermittently mute seemingly due to slow routing on behalf of the pfSense unit. When I reconfigure the devices to look at the Cisco for their GW, audio is 100% stable although this adds other inconveniences that I'd like to avoid, hence my preference to attempt to use the pfSense SG-1100 for routing.

The specs on the SG-1100 for my use case should be able to conservatively handle 480 Mbps. I'm getting equal instability when I pass only one flow of audio and PTP at about 4 Mbps, and all available devices yielding about 20 Mbps for L3 forwarding.

However, the dashboard reports CPU usage around 75% on average.

Does anyone have any insight as to possible tuning handles I may utilize to smooth this out?
or something I'm not looking at?

Thanks,
~A