Asterisk problem: internal call every 5 mins

Hi i’m new with asterisk,
Sorry with my bad english but this is the most complete forum that i read and i need some help.

I was many days trying to configure asterisk in my office and it’s work with the options that i need, but now i have a problem. I start asterisk and all go fine, i can make and receive internal and external calls with voicemail and music on hold, … it’s works fine 2 or 3 days but suddenly my extension receive a internal call from asterisk, and it’s ringing 4 or 5 seconds and then hangup, and asterisk repeat this process every 5 or 4 minutes. If i restart asterisk sometimes the problem disappears but passed a few days it comes again.

Someboby have any idea about the problem? thx.

do u have a voicemail when that happens? Its probably VMWI enabled on your user, so the system is notifying ur phone of a new voicemail every time it re-registers