Some calls go straight to voicemail without ringing

It occurred to me that some of the time voicemail pops up in our company support box, but my desk phone doesn’t ring.

To test, I use my cell phone to call in and press our support line button and it always rings. I cant simulate the error. However, it is a daily occurrence. I sit by the phone all day, it it rarely rings, voicemails show up.

Here and there clients have made this observation about their own asterisk systems, and are looking for a resolution. This phenomenon apparently affects a wide swath of versions and scenarios.

Ive been working on systems for the past 5 years or so, but I cant explain why it would do that.

Show us your logs. You can enable the sip debug and set the debug verbose to 3 and activate the full log. When the issue occurs take the time, then you can search in the full log with that time. Obvioulsy you log will grow faster but always you can rotate it.

Probably the phone gets unregistred (network latency?) and the phone call goes directly to voicemail…