NB-IoT download only working with very smal files

Hi Friends.

I have a problem with NBIOT Testing.

As per operator, for 180 kHz NB-IoT Max Downlink Data is 156 kbps.

Now we are trying 200KB file, 300KB file in downlink test, getting sometimes success and sometimes failure with code 404.

So, what may be the reason of this failure?

If trying 500KB file getting all time failure.

Have you tried to change the server and test it?

There are many public servers available you can use for small files.

It needs unsecured (http) server for the test.

All free servers having security like http(s).

This is http server:

If you are testing in Lab, you can create your own small FTP or HTTP server behind PGW and use that for testing.


No this is not a lab testing, NB-IoT is configured on a site in the field.


What is the reason for no https?

Personally I don’t recommend public server for performance testing, since you don’t know the load on server.

But for quick verification this should be good.

This server having large size files more than 5 MB which we have tried and got failure results.

We are trying our own server for testing.

100kb file from server 100% success.

200kb file getting success and sometimes failed with code 404 and same with 300kb file.

Run a Wireshark trace for failure and success scenario at UE nad server side.

Compare and see what’s happening.

Theoretically a file size shouldn’t impact the download.

Presuming the file names are consistent for 100kb and 200kb file.

I don’t have this tool, is anyone here using Wireshark tool?

It’s free, many people use it to analyze pcaps with packet captures of different protocols.