Python requests is too slow with certain WI-FI connection

Question

I'm working on a TTS app using AWS Polly in Raspberry PI 3 B+ and when I post a text using Python requests it take a long time receive the response, around 16-17 seconds. This happens only with a certain wifi connection. I have tried 3 different wifi connections in which 2 of them are mobile hot spots and the request.post gives a response within 2 seconds. When I connect to a wifi modem which is a 4G/5G connection it takes around 16-17 seconds. Modem speed is not an issue here as it gives minimum 120Mbps speed. Pi connects only with the 4G connection here not 5G. I have enabled the "Disable IPV6" option in in the wifi settings. Why it's slow only with a certain connection which is a faster network?

import requests
import time

start = time.time()
res = requests.post('https://myawsAPI_XXXXXXX', json={"body":"Activate barn door protocol."})
print("Elapsed time1:", time.time() - start)

Blockquote

Elapsed time1: 17.350016117095947

Answer 1

I figured out the problem here. I had to disable the Ipv6 in the pi sysctl.conf.

To disable ipv6, you have to open /etc/sysctl.conf using any text editor and insert the following lines at the end:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

and reboot. If IPv6 is still not disabled, then the problem is that sysctl.conf is still not activated. To solve this, type the command:

sudo sysctl -p

You will see this in the terminal:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

After that, if you run:

cat /proc/sys/net/ipv6/conf/all/disable_ipv6

1

If you see 1, ipv6 has been successfully disabled. For other methods please check this page.