Grandstream and some other embedded devices or IoT devices come with client or management applications. These applications directly communicate with the device to do things like, assign IP address or get model information, and etc.
Traffic from these applications can be useful to look at.
Here's an application to search for Grandstream camera on your network:
It sends out UDP probes and waits for the camera to respond with information.
Also notice that it lets me change the camera IP address and Wifi Configuration. The camera model I have (GXV3611IR_HD) doesn't have a Wifi module.
I know that IP modification is done via UDP and I don't care too much about that right now. I am interested in the wifi config feature.
I was running Wireshark to capture the data and I clicked Scan.
Red part is what the management application is sending to the camera. Blue is the reply.
Notice the basic auth. It's admin/admin. I know that isn't the correct combination because I changed it.
Another thing you should notice is the user agent. It's GSurf/4.0.
When I visit /goform/wireless or /Pages/wifi.html, via my browser, I'm given a login prompt.
But after changing my user-agent to GSurf/4.0, I'm a able to browse the authenticated pages freely.
But sadly, I can't really do much with it.
Below you can see that I tried to add a user and failed.
Anyways, remote management applications or client applications are some of the things you may want to examine if you're already not doing it.
