Constant Incoming Call From "External" 1

[DeepMike]

IPO R9.1 and the reception phone is constantly getting call alert from "External" but on picking the phone there will be no caller. This is happening continuously.
They are using Analog Trunk lines.
On System Status there will be no caller ID for that incoming call and sometimes it shows the analog trunk line as in Pre-Alerting mode continuously.
How can we fix this issue and whats the cause?

 

[sizbut]

Check with your line provider. This used to be common with providers who provided there own voicemail service. With that, they would regularly send their version of message waiting indication which is enough make the system think there's an incoming call.

Stuck in a never ending cycle of file copying.

 

[budbyrd]

Could also be a bad port, I have seen that before. Try moving that line to a different port. Could also be line noise, just enough to make the system think it is ringing.

Dermis and feline can be divorced by manifold methods.*
*(Disclaimer for all advise given)--'Version Dependent'