This method works for both original and patched OEM firmwares (and also for OpenWrt “factory” images that are masqueraded as OEM files).
Look for or Product Class .
For those wanting a total overhaul, the V2.5 hardware can sometimes support OpenWrt , though this requires careful flashing via CFE web recovery or JTAG for advanced users. How to Update or Patch Your Firmware zte zxhn h108n v25 firmware original patched