Please follow the steps below:
The maximum number of users is limited to 3. However, it also depends on the total bandwidth accessed to this device from clients. The maximum data throughput of the device is around 20~25Mbps for UDP mode and 10Mbps for HTTP mode. Therefore, the actual number of connected clients is varying by streaming mode, settings of resolution, codec type, frame rate and bandwidth. Obviously, the performance of the each connected client will slow down when many users are logged on.
The difference between UMG-2200 and UMG-2000 is the PSTN support numbers. The UMG-2200 equips with 8-Port FXO for flexibility applications.
Maybe too many IP cameras have been installed on the LAN, and then NAT router is out of resource to support more cameras. You should turn off and on NAT router to clear out of date information inside router.
Please check the following below:
Yes, it is weatherproof, and can be installed outdoors.
Maximum 20-25 meters. Please note: the mentioned ranges are indicated as a quick guide and the actual results depend on reflectivity of the scene, light source, weather conditions, etc.