DSCP processing in OPNsense

[clownschiff]

Hi all,

I have two questions regarding the processing of DSCP-tagged packets in OPNsense and I hope someone can give me a hint or two. My goal is to prioritize VoIP traffic in my network via DSCP with the EF-tag.

In my current setup the SIP-client on Windows workstations tags SIP and RTP packets with the value EF (confirmed with Wireshark). The packet passes the PBX (3CX) and reaches OPNsense, still with the EF value set. So I think everything is alright so far.

Now my two questions are ...

• Will OPNsense prioritize the EF tagged packets by default or do I have to add some configuration for this?
• For incoming VoIP packets from WAN exists a NAT rule pointing to the PBX. The according auto-generated firewall rule can not be edited to tag these packets with EF. Do I just delete these rules, recreate them manually and add the DSCP tagging or is there something else to do?

The documentation isn't very verbose about this and I would be glad if someone could give some insight.