I setup delay pools on my squid. however, I want to limit download speed on file extension, let say exe, zip etc.

Here's my delay pools

acl extensions url_regex -i .exe$ .mp3$ .tar.gz$ .gz$ .rpm$ .zip$ .rar$ .avi$ .mpeg$ .mpe$ .mpg$ .ram$ .rm$ .iso$ .raw$ .wav$ .mov$

acl dept1 src
acl dept2 src
acl dept3 src 1172.10.101.1-

delay_pools 4

delay_class 1 1
delay_class 2 1
delay_class 3 1
delay_class 4 1

delay_parameters 1 250000/312500
delay_access 1 allow dept1

delay_parameters 2 125000/187500
delay_access 2 allow dept2

delay_parameters 3 -1/-1
delay_access 3 allow dept3

delay_parameters 4 250/625
delay_access 4 allow extensions
It works per bucket, I test using 172.10.10.dept1_ip and dept2, dept3 ip, and it works. I only allowed max bandwidth allocated (tested using speedtest,net)

However, when I download let say .exe file, it download the max speed, and doesn't follow my delay_class 4. Besides limiting per bucket, i also what I control/ limit the download speed. (eg. 1mbps per bucket, but 20kbps download speed)