sending COA + burst

hi all,
I use COA to sending Mikrotik-Rate-Limit .when I send MAX limit it look ok.but when I send it with burst detail it doesnt work.

echo “User-Name=test,Framed-IP-Address=10.10.10.100,Mikrotik-Rate-Limit=128k/128k” | radclient -x 192.168.0.33:1700 coa mysecret

Sending CoA-Request of id 88 to 192.168.0.33 port 1700
User-Name = “test”
Framed-IP-Address = 10.10.10.100
rad_recv: CoA-ACK packet from host 192.168.0.33:1700, id=88, length=36
NAS-Identifier = “MikroTik”
NAS-IP-Address = 192.168.0.33

it doesnt work :
echo “User-Name=test,Framed-IP-Address=10.10.10.100,Mikrotik-Rate-Limit=128k/128k 384k/384k 128k/128k 10/10 1 0k/0k” | radclient -x 192.168.0.33:1700 coa mysecret
Sending CoA-Request of id 88 to 192.168.0.33 port 1700
User-Name = “test”
Framed-IP-Address = 10.10.10.100
rad_recv: CoA-ACK packet from host 192.168.0.33:1700, id=88, length=36
NAS-Identifier = “MikroTik”
NAS-IP-Address = 192.168.0.33

Did you get any solution for this?