Analog Trunk - Door Entry Phone

[Felix]

Hi all,

I have a 3300 that has incorporated a door entry system. This is connected via an analog trunk port (ONS) with the built in ports.

The trunk is programmed via the trunk attributes to dial a group of phones. When the door entry button is pressed however no ringing is evident. The door entry installers say that the single pair is generating the voltage for the phones to ring but nothing is heard.

I created a trunk group which seized the analog port and when the door entry is pressed and the trunk seized you have communication across the trunk.

I have changed parameters in the CO Trunk Circuit Descriptor including Ringing Expected amongst others but nothing seems to be working.

 Line Start Type Loop
 Post Call Metering No
 Guard Timer 800
 Calling Party Disconnect No
 Dictation Trunk No
 Ignore Far End Disconnect No
 Disconnect Timer 500
 Ignore Far End Reversal During Seizure Yes
 Ringing Expected Yes
 Seize Timer 10
 Address Signalling DTMF
 Fake Answer Supervision After Outpulsing Yes
 Ignore Answer Supervision Yes
 Release Supervision Expected Yes
 Audio Inhibit Until Answer Supervision Yes
 High Loss Option No
 Balance Network Setting National Complex
 Trunk Category Short
 Perform seize test on out-of-service trunks Yes
 Ground Condition During Busy Out Removed
 First Meter Pulse Is Answer No
 Minimum Ring Detection Timer 200
 Drop Digit Rcvr for Outgoing Audio Before Ans Sup No
 Flash Timer 300
 Call Clearing Signal Disconnect
 AC Impedance National
 CLASS Trunk No
 Milliwatt Tone 
 Silence Tone

I have also tried to connect the door entry to an analog extension on hotline to the group but that does not work either.

Has anyone else ever come across difficulties with this? Any help would be much appreciated.

[x-man]

I would check that the door phone is generating the correct ring pattern for the mitel to recognize which will be the same as our i/c ring from BT. Often these trunk ones are set to US patterns which won't work as its a single ring (voltage present for 2 secs I think) rather than a ring/ring the Mitel is expecting (i.e. ring ring voltage pause voltage) and the cadence needs to be correct as well. I used to know this stuff off by heart but since the ascendance of IP telephony I don't use the knowledge much anymore. I would also check that the unit is putting out -48 DC volts in standby to make sure the Mitel knows there is a line present and that the voltage of the ring is 80v AC. fairly easy to do with a multi meter.