I have a problem with Asterisk 11.5.1.
When I pick up an incoming phone call sometimes I need to transfer to someone else in the organization. I then dial a number on my phone, and press Xfer. Sometimes it works well, I mean, the number I dialed get the call and can chat with correspondent. Sometimes, the number I dialed get the communication and while he chats with correspondent, gets a bip every 5 sec(incoming call notification). Just like if I transferred the call twice. I happens with some internal extensions, not all, but never for others. Does anyone have already seen this kind of behavior?