SOYO G668 Ethernet IP Phone User Guide
Appendix: Port Forwarding
Note: Try port forwarding only when you have router or firewall in your network and your IP phone do not function correctly.
Applications running on TCP/IP open connections to other computers or Internet devices using something called ports. Sometimes your router or firewall will block certain communication ports between your network and outside traffic. These ports might be the ones needed by the IP phone to communicate with the Internet. You will need to configure your router or firewall so that certain port(s) in your network is accessible from the outside.
Different router manufactures have different process for port forwarding. So you will need to refer to your router manual for port forwarding configuration instruction.
Different VoIP protocols require different ports for communication. So you will need to consult your VoIP service provider to find out what port ranges should be opened, and forward these ports to the IP address of your IP phone.
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