Problem phenomenon:
After the phone rings, the called party picks up the phone and answers the call. The call establishes the voice normally. The called party hangs up and returns to standby. However, the caller is still on the call and cannot automatically end the call.
Possible Causes:
When the called party hangs up, it will send a bye message to the caller, requesting to end the call. Because the request message of the phone is sent to the address in the VIA field of the previously received message. Some of the SIP messages sent by the PBX that are mapped to the public network through the NAT, the VIA field is the address of the private network, and the subsequent request message of our phone cannot be correctly delivered to the peer. Unable to hang up.
Solution：
In the phone configuration, enable the “Direct Contact” function so that the request message of the phone can be directly sent to the address specified by the contact field of the other party.
How to open the phone “Direct Contact”.
- Log in to the phone on the web page, select “System” – “Configuration” – “Right click here to SAVE configurations in ‘txt’ format”, select “Save Link As”, and save config.txt.
- Open config.txt, ctrl+f find the keyword Direct Contact, change SIP1 Direct Contact :0 and SIP2 Direct Contact :0 to SIP1 Direct Contact :1, SIP2 Direct Contact :1 Then save the file.
- Log in to the phone in the web page, select “System” – “Configuration” – “Import Configuration”, click “Select”, find the config.txt file that you just modified, select it, click “Import”, wait for the phone to restart The update is then complete.
