There are 2 methods you can use to connect BioStar 2 devices to the server if the devices are in a different network from the server.
1. Server with public IP:
This is also referred to as the WAN network method.
If you have a server with a public IP, the devices can connect to the server with Device → Server mode.
If you want to connect the device using the server URL, make sure you have configured the DNS server address properly.
If you use virtual private network you can configure the network to seem like the devices are in the same network as the server.
You should also use Device → Server mode for the devices.
Device to server mode configuration is essential in both options because the server cannot detect if the device is disconnected in the network.
The device should reconnect to the server again when it realizes its disconnected in device to server mode.
If you are not sure what Device → Server mode is, refer to the following article: [BioStar 2] Connection Modes and Troubleshooting Connection.
Make sure proper port forwarding is done on the routers for both options. Refer to the article below regarding the device port:
[BioStar 2] Server and Device Port Usage
To resolve your issue please check the following:
1. Port Fowarding & Firewall
Check that port forwarding is done correctly and the firewall is not blocking server and device ports.
Refer to the following link regarding ports: [BioStar 2] Server and Device Port Usage
2. Upgrade the Firmware
Upgrade to the most recent version as provided at our homepage download center:
Firmware revision notes are included in the firmware zip files.
3. Check the MTU (maximum transmission unit)
Check the MTU of the router and suprema device.
Suprema device MTU should be lower than the router's MTU.
i.e if the Router's MTU is 1500, try setting the device MTU to 1400 or 1350 to be safe.
If you are using an 1st generation entry level device, (BioEntry Plus, Xpass, Xpass S2, BioLiteNet, BioEntry W) these devices do not have a operating system with a auto-negotiation feature so you have to manually adjust the MTU size lower than the router's MTU.
Refer to the article below to understand MTU:
Set the device to device to server connection since the server will not be able to see the device in the same local network to check its connection.
4. Check Connection Mode and Device Connectivity
Connection mode should be device to server. Refer to the guide below.