On the LAN:
- one usually has unfettered access to the camera's raw stream.
- more bandwidth is available.
- more bandwidth = better image quality possible.
- the camera stream MAY be available if forwarded and not firewalled through a router.
- bandwidth is scarce compared to the LAN.
- image quality can be lower for live viewing.
- ZM's live viewing mechanism is very CPU intensive and can be avoided if the live feed is forwarded through the router or one is on the LAN.
- Saving a H.264 stream (which is used by most high resolution IP cameras) to JPEG kills image quality, so viewing directly from the camera gives a better picture.
The decision could be based on
- The client's IP address (is it on the same subnet as the camera?)
- Is the camera's IP address in one of the reserved private ranges, e.g. 192.168.x.x?
- Is the client's IP address or subnet in a special, manually determined list for direct camera access?