DVRDealcom

this camera has no audio, use higher level model, such as 2532, 2632, 2732. those comes with audio.

The 2332 has better night vision and is hard to push or move.... 2332 has matrix IR, that's so-called 3rd generation infrared. it gives longer night vision distance and better IR coverage (means IR won't only focus the center point), so it's better than 2032

You can't compare all-in-one system with ip system. they can't be compared. because most all-in-one system are still analog with tv lines, and ip system is ditital and megapixel. it gives you 3-4 times better video quality.

This camera has no SD card, you can't save data in the camera. But you can choose save data in your remote computer or NVR.

Any IP camera with onvif 2.3 (onvif profile s) will work with dahua NVR.

If you buy from ali, it's hard to do RMA and support. For return, you need ship to overseas, time and money costs. For your question: 1. Remove all cameras. search again to connect them. 2. run SOAP software in your computer, check if the cameras IP address have been changed. 3. ask seller to give you english software to hack the NVR back to english.