[Q] Why the OpenNetMeter shows different results compared to Windows's `Data usage` report

[dehghani-mehdi]

I reset both and after a couple of days I compare them, OpenNetMeter shows a different number, it is not a big deal, I just want to know why.

[Ashfaaq18]

Hi @dehghani-mehdi, did you run this test with the OpenNetMeter settings option "Monitor these networks" set to "Public" only?

If its set to the default option "Both", it would also monitor the data packets sent internally between processes and networks without internet connection.

[dehghani-mehdi]

@Ashfaaq18 I'm sorry, I was not accurate in my first comment. OpenNetMeter shows different number than Windows's one. based on that numbers I think your theory is not quite right. but yes, I didn't change that option. I tested with the default one.

For more clarity, OpenNetMeter shows 175MB download and 141MB upload, and Windows shows 204MB as Data usage.

[dehghani-mehdi]

Actually OpenNetMeter shows different result compare to IPv4InterfaceStatistics class. I didn't check your code, did you use a different approach to get that information?

Update: I saw what you did, seems ok, but still I don't know why Windows reports a different number.

[Ashfaaq18]

Hi @dehghani-mehdi, thanks for clarifying further.

For more clarity, OpenNetMeter shows 175MB download and 141MB upload, and Windows shows 204MB as Data usage.

regarding the above, I'm pretty sure that windows data usage includes both the download and upload usage combined. I couldn't find a source from Microsoft regarding this but found a forum post which confirm this.

So taking the above into consideration, this application's combined usage is more than the window's usage ( (175+141) > 204). Setting the option to "Public" only should drop the values lower that what you have. This should
bring the usage values closer to window's data usage. This is assuming that windows data usage monitors only public and not private/local data transfer.
If windows data usage includes data usage within private networks and processes then its something i should double check on. I'll leave this issue open and report back with some findings. Quite busy these days with work.

Also, I've seen quite many reports about the inaccuracies in window's data usage stats. A simple google search should show a substantial amount of results. Not sure if the reports are accurate though. This is something to consider.

[Ashfaaq18]

You can also try check the detailed data usages between both the data usage apps.

1. First, isolate a common app shown in OpenNetMeter(ONM) and window's data usage(WDU).
2. Compare the isolated app's data usage in ONM and WDU, the higher the difference the better.
3. Reset ONM and WDU data usage, start using this isolated application again with an internet connection.
4. Observe and compare the data usage for this application between ONM and WDU.

This should show the data usage increment and maybe you can take a guess if ONM or WDU provides accurate info. If you need very accurate results you may have to use an application like wireshark and monitor the data packets.

In the future, ill try to include some comparisons as a benchmark in this repo.

[dehghani-mehdi]

Also, I've seen quite many reports about the inaccuracies in window's data usage stats

I didn't search about that, but I think that's correct, that's why I am looking for an alternative and installed OpenNetMeter.

If you need very accurate results you may have to use an application like wireshark and monitor the data packets

No, I'm not looking for that amount of accuracy.

I'll try to do what you said (4 steps) asap.