Setting ToS/QoS for VoIP on Mikrotik

Question

I have a Mikrotik router which looks like iptables. I need to setup QoS to ensure VoIP phones get top traffic priority. How do I know what ToS to use and how would I get it? I searched and can't seem to find the ToS for VoIP.

My rule set so far is as follows:

/ip firewall mangle
add chain=forward tos=XXX action=mark-packet new-packet-mark=VoIP passthrough=no comment="voip" disabled=no

/ queue tree
add name="ether1_voip" parent=ether1 packet-mark=VoIP limit-at=0 queue=default priority=2 \
    max-limit=0 burst-limit=0 burst-threshold=0 burst-time=0s disabled=no

Solution

Run Tools > Torch using the latest versions of Mikrotik (which include DSCP/TOS in the Torch tool) during a voip call to find out the DSCP/TOS for those packets.

Update:

If you are using an older version of Mikrotik that does not support DSCP/TOS on the Torch tool, you can run Tools > Packet Sniffer to capture the traffic (or stream it directly to a PC) and then open it on Wireshark to find out the TOS field for the VoIP packets.