Capture diag frame data of Qualcomm Quectel modem using an open-source app in C++

Question

I want to capture (and maybe dissect) the diag data obtained from Qualcomm Quectel modem (EC25) in linux. I have done this for mobile devices with Qualcomm chip-set in android environment using some opensource projects such as mobile-insight and SnoopSnitch. So I can dissect almost all the diag data obtained from air interface like RRC Signaling Message and ...

Now, I need an open source program in C++ to capture diag frames from Quectel chipset. I know that osmocom has similar project in this area. So what is the best open source c++ app to use? (If osmocom is the best, please guide me that project because I'm somewhat ambiguous in the osmocom document)

Answer 1

So what is the best open source c++ app to use?

Define "the best". There can be many criteria: completeness of the implementation, protocol support, maintenance status and so on. What exactly do you mean?

I need an open source program in C++ to capture diag frames from Quectel chipset. I know that osmocom has similar project in this area.

Osmocom has https://git.osmocom.org/osmo-qcdiag/ in C. Unfortunately, this project has no wiki (https://osmocom.org/projects/osmo-qcdiag/wiki shows empty page), but there is a brief README .

Building osmo-qcdiag from source is rather typical. You would need to have libosmocore: either build it from source, or install from packages. Then do the following:

$ git clone https://git.osmocom.org/osmo-qcdiag
$ cd osmo-qcdiag/src/
$ make

After running make, you'll find the osmo-qcdiag-log binary.

$ ./osmo-qcdiag-log /dev/ttyUSB0

osmo-qcdiag is not actively maintained and is not user friendly at all. It simply gets diag data from the modem, decodes known packets and sends them over UDP/GSMTAP. You can use Wireshark to dissect GSMTAP frames. That's it.

Personally I prefer using the following tools:

• https://github.com/P1sec/QCSuper, and
• https://github.com/fgsect/scat.

They both are user friendly and written in Python.