I decided to dig up the old thread on qos_map to see if anything has changed in the interim with the version 18 series: Using DSCP for QoS
EDIT:
Hey all, I discovered something interesting....
Setting up tagging and by default tagging everything cs2 seems to have been the cause of my erratic behavior. If I tag cs2 my ATT connection seems to down-prioritize or throttle my traffic (possibly my ACKs?), not sure what, if I tag cs3 as my "normal" it seems to be ok. Basically changing that one line made things go from highly erratic to clean as a whistle. So I've switched to CS3 as my "default" tag.
Also, they symptom was a much slower start on download but reaching a moderately reasonable level, but on upload completely lack of bandwidth eventually resulting in bandwidth dying out almost altogether, which is why I think it has to do with ATT equipment interpreting outgoing DSCPs I send.
More information: tc is dead, long live nftables... Here are rules I use to classify into my multi-tier HFSC shaper:
meta priority set 1:40 ## default
ip dscp {ef,cs6} meta priority set 1:10
ip dscp {cs5} meta priority set 1:20
ip dscp {af41, af42, af43} meta priority set 1:30
ip dscp {cs1} meta priority set 1:50
ip6 dscp {ef,cs6} meta priority set 1:10
ip6 dscp {cs5} meta priority set 1:20
ip6 dscp {af41, af42, af43} meta priority set 1:30
ip6 dscp {cs1} meta priority set 1:50
This replaces about 40 lines of more complicated tc filter commands that look like:
/sbin/tc filter add dev ${DEV} parent 1:0 protocol ip prio 60 u32 match ip tos 0x88 0xfc flowid 1:30
/sbin/tc filter add dev ${DEV} parent 1:0 protocol ipv6 prio 61 u32 match ip6 priority 0x88 0xfc flowid 1:30
some of which included using tc to match tcp / udp ports instead of DSCP values.
All I need now is tc to set up the hfsc shaper itself, which is much more understandable than the u32 filter syntax.
I think nftables provides the ideal comprehensive method for QoS afficionados (gamers, Voipers, guest network providers etc) who want more control than the very good defaults that piece-of-cake offers.