Extension Registration Issue

[yhbilisim]

Hello, has anyone encountered the following issue?

When I try to register extension 1000 using UDP, it sometimes succeeds and sometimes fails, showing the error below. However, without making any changes, when I switch to TCP, it registers without any issues. What could be the reason for this?

 

[pbxgeek]

It's hard to tell without seeing what the phone is sending in the second Register packet. But my best guess is that it's not getting a response from the server and tries to register again. This is likely due to a firewall issue. TCP has better capability to penetrate through the firewalls. If you want to have no issues at all in any circumstances, then TLS is the way to go. But there is an additional overhead with that.