I think it's a small bit broken I'm afraid !!
It's a 7400 with mcp 4.60b with a Pri card and sip trunks for outgoing and a voicemail card and OAS card it has 5 x 16 dli cads and a sli card
The system is locking up in that the voicemail the Pri card and the sip trunks go inactive after a couple of day ( could be 3 days could be 8 days) no real pattern to it. The phones still work internally but no incoming calls no voicemail and no outgoing over sip a reboot and it all comes up fine until the next time .
So far we have changed the svmi-20e to a new svmi-20i and changed the chassis but no luck. It's behind a mikrotik router and it's locked down to the ip of the sip provider and had a mikrotik engineer look over the config and he says it looks ok. There is also exchange on it. I have closed port 5090 as I felt it was more frequent when we had remote access to it. It's still happens but it think no as often. I was thinking a DOS attack but not sure how ?
Any ideas