Question: Why does the GXV3140 fail to register to the SIP server?
Answer:

You should make sure that the phone is connected to the network and the phone is able to obtain an IP address. Secondly, check if the account is set to active by setting the “Account is Active” configuration in the Account page of the web interface to “Yes”. Additionally, check if the login information and the SIP sever is correct. If the SIP server is wrong, the phone cannot contact the SIP sever for registration. If the login information is wrong, the SIP server will reject the registration request of the phone.

If all of these are correct, there may be a problem with NAT traversal. If the GXV3140 is on a LAN and needs to register to a SIP server on a public IP, NAT traversal must be enabled. If the NAT type is unknown, it is recommended to select “Auto”.