Appendix K - Applications
Ports In/Out of Service
When a group call to a VMI extension is not answered within 30 seconds, the
call either is sent to another available VMI extension in the Calling Group
or is queued back to wait for an available extension in the Calling Group.
For an integrated VMI extension, the control unit sends messages to inform
the VMS that the extension is out of service. Both the VMS and the Calling Group
software mark the unavailable port as out of service. If all VMI extensions
go out of service, the system generates a hardware error report.
Every 10 minutes, the system tests an out-of-service VMI extension. If the
extension responds to the test, the VMS and the Calling Group software mark
it as in service . For an integrated VMI extension, the control unit informs
the VMS by sending extension-in-service messages.
