I've now made some progress with the device.

When powered on, it apparently creates a WLAN access poit with ssid "Chromecast4583" and is willing to accept connections, granting DHCP lease for an IP address 192.168.255.252.
The other end acts as a GW and presents itself at 192.168.255.249.

There's just 2 ports open, DNS and 8008. The device seems to be waiting for something on the latter port, and does not give an indication of what exactly is it.