ChromeOS version: any
ChromeOS device model: any
Case#: 17533211 

Description:
NetworkThrottlingEnabled download speed limit 2x more than configured

Steps to reproduce: 
1. Setup NetworkThrottlingEnabled as :
{
   "download_rate_kbits": 20000,
   "enabled": true,
   "upload_rate_kbits": 10240
}

2. Test on speedtest.net

Current Behavior / Reproduction: 
40Mb/s Download speed  
10MB/s Upload speed

Expected Behavior: 
20Mb/s Download speed  
10MB/s Upload speed

I suspected maybe speedtest.net was wrong, however, check HAR file attached (filter by word "download, to get actual data downloaded), per screenshot attached

So in 15000 mseconds (15 seconds) it received:
18972591 +
12615626 +
11272147 +
15925185 +
11632595 +
7143397 
=
77561541 bytes

77561541/1048576=received 73.96 MegaBytes in 15 seconds, so speed will be: 73.96/15*8=39.44 Mbit/s, which corresponds to speedtest result.

Video: (where it is configured as 20x20 and showing 40x20): 
https://drive.google.com/drive/folders/1qZ0PEbsZKJkXizQriSBYlYhUU8VbNA5x?usp=sharing
 

Deleted: download-har.png 111 KB

	download-har.png 111 KB View Download

Deleted: www.speedtest.net20x10-2.har 6.1 MB

www.speedtest.net20x10-2.har 6.1 MB Download