I have D-Link Router DSL-2730U that support busybox OS and iptables version 1.4.0 I managed successfully to block the host for being connect to the internet using the following commandblock by ip addressiptables -I  FORWARD -d 192.168.1.6 -j DROPOr By mac source iptables -I FORWARD -m mac --mac-source bc:20:a4:ff:79:80 -j DROPThe only problem now i have is trying to limit transfer speed rate (upload & download) to be only serve 30/kbps by MAC Address using iptables I tried to make iptables rule like iptables -I FORWARD -m mac --mac-source bc:20:a4:ff:79:80 -m state --state RELATED,ESTABLISHED -m limit --limit 100/second --limit-burst 30 -j ACCEPTBut it didn't workNote : this router cannot modify , delete or add any files . i cannot make a bash or script file inside the router run , and unfortunately the iptables connlimit module not supported in this iptables version too 
Limit transfer speed rate by Iptables Rules
linux;bash;iptables;busybox;telnet