Compared with traditional on-premise IPPBX and other cloud PBX brands, Yeastar Cloud PBX has fewer issues with firewalls but it doesn’t mean zero issues. When you do experience a connection/registration issue, you may follow the below instructions to resolve it:

1. Verify with 4G/5G connection.

You may first attempt to connect your Linkus/IP phone from a 4G/5G or 4G/5G hotspot connection. If you are able to connect and make/receive calls, it means there is nothing wrong with the Cloud PBX server.

2. Verify with WiFi/LAN connection and firewall OFF.

Now switch your connection to WiFi/LAN, if you experience a connection/registration issue, please first try completely off any firewall on your router. If you are able to connect and make/receive calls, it means the firewall is causing an issue and you should open these ports on your router’s firewall if you want to turn on the firewall.

If your router has the option to whitelist IP addresses, you may white list your Cloud PBX’s IP address there too.

3. If you encounter a registration issue and in the event that you don’t have access to your router at all, you may consider this alternative solution:

  • Change to use the TCP transport, if it doesn’t work, try the next step:
  • Change SIP port and use the TLS transport

Solution

1. Change to use the TCP transport

1) enable TCP port on the PBX

2) select transport to TCP for extension

Next reboot your device, or if you are using linkus, you are required to logout and login again to have the settings to take effect.

If the above steps are not helping, try:

2. Change SIP port and use TLS transport

1) Enable TLS on PBX and change SIP port.

2) Select transport as TLS for extension

Next reboot your device, or if you are using linkus, you are required to logout and login again to have the settings to take effect.

If you have not enabled TLS before, you will be asked to reboot the server as well, kindly follow the instructin and reboot in order to have the configuration to take effect.