simple way to limit pps :
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:global kl44 "192.168.181.25/30"
# add klient ip
/ip firewall mangle add action=mark-packet chain=forward comment="" disabled=no new-packet-mark=$kl1 packet-size=0-40 passthrough=yes src-address=$kl1
# mark small pakets 0-40 bytes
/ip firewall filter add action=accept chain=forward comment="$kl1" disabled=no limit=30,5 packet-mark=$kl1
# accept only 30 small pakets from ip
/ip firewall filter add action=drop chain=forward comment="" disabled=no packet-mark=$kl1
# drop if more than 30pps
/ip firewall filter add action=accept chain=forward comment="" disabled=no dst-address=$kl1 limit=170,85
# accept 170 pps for download
/ip firewall filter add action=accept chain=forward comment="" disabled=no limit=70,35 src-address=$kl1
# accept 70 pps for upload
/ip firewall filter add action=drop chain=forward comment="" disabled=no src-address=$kl1
# drop ( limited upload PPS)
/ip firewall filter add action=drop chain=forward comment="" disabled=no dst-address=$kl1
# drop (limited download pps)
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170 pps download speed is about 1.9 mbs with speedtest
70pps upload speed is about 0.5mbs with speedtest