3300 Analog Trunks not clearing down 3

[pea123]

Have a 3300 using only analog trunks.The problem I am facing is that it does not clear down trunks after use for either incoming or out going calls.
Have tried setting up <CO Tones to Detect> according to the provided Cd but this has failed.Some trunks even play out MoH for days on end until LS/GS card is reboot.This is so for 3 to 4 other 3300s.
Does anyone know what could be the problem?IDEAS WELCOME.

 

[kwbMitel]

Couple of points of clarification required.

LS/GS? - Are the trunks in a 2K per node? Did you mean LS Class as this is what the embedded ports are or some other scenario that I can't fathom.

CO Tone Detection? - Does your CO provide tones on disconnect? This is quite rare, please elaborate on location and telco.

Are you able to duplicate the issue by making a call and hanging up, or same for inbound call?

Most likely scenario, based on numerous assumptions, is that the trunks are being conferenced together by users or by transfering calls to cell phones. If this is the case, you will always find paired trunks locked up and diconnecting 1 will disconnect the other. Unfortunately, there is no solution for conferenced trunks other than education and prudent use.

*******************************************************
Occam's Razor - All things being equal, the simplest solution is the right one.

 

[pea123]

Located in Southern Africa & the telco uses Huawei switches, not sure about the tones.
The 3300 in question is an AX rel 9 using 4+12cards (4 of them).So Im wrong in saying LS/GS.

They normaly transfer calls to cellphones.
Each card might fail to clear 1/2 lines at times.Once the lines fail to clear down they stay like that for days until someone pulls put the card & puts it back.
They then work normal for less than 2 days.

On the other hand, analog stations sometimes display <out of service> on the 5550ip console when attempting to call them.Could this be arising from a programming error.<Thinking of System Options & Class of Service assignment>

 

[LoopyLou]

have had many problems with calls to cell phones and the cell phones don't always provide a proper disconnect at the end of a call.

 

[pea123]

Whilst the lines will have failed to clear down doing an Individual Trunk Access from an IP phone shows that some trunks would have failed to clear down dialed landline numbers & never cellphones because when making a cellphone call they get connected using GSM of which theres no problem of failing to clear down on the ports connecting to the GSM terminals as analog trunks.
Still more ideas welcome.

 

[Jakt99]

Not sure if this will assist.

In the past, where I have experienced issues clearing down analogue trunks on incoming calls terminating into say auto - attendants, especially where the telco cannot provide a disconnect signal (EG reliable line reversal or positive disconnect "current Break"), I have installed disconnect modules between the 3300 analog trunk and telco.

A disconnect module is a device that listens to sound energy generated from the telco when the calling patry disconnects (busy or reorder tone or dial tone) and when satisfied the signal is valid (several seconds analysis), will then provide the mitel trunk with a positive disconnect signal (half second current break) which inturn clears down the call.

The disconnect module isn't fool proof and tad fiddly to set up at first. Its beauty in operation is also its Achilles heel, you need a relaible, long burst of sound energy from the telco when the caller hangs up, otherwise it doesn't function.

Not sure where you can purchase units nowadays or who manufactures them any more. The last device I utilised was an EEM-8208 MAX Terminator, which supported up to 12 pstn trunks. Manufactured by Electronic Tele-Communications, Inc (Norcross, GA, USA), way back in the nineties. I have a copy of the install manual (PDF), if you would like to peruse.

Let me know and I can email it to you.

 

[kelvinzhong0908]

Config the system configuration--trunk--anlog trunk----Loop start/ls-gs--CO Tone Detection form,you can solve the issue.

 

[sterling5005]

Ask the phone company to turn on "disconnect supervision".

 

[jon83]

Here in the UK its the disconnect timer needs to be set higher than BT which i think is 180ms.

 

[odiefoxydog]

Hi,
I had an issue with this recently in the UK on analogue trunks being answered by the embedded auto attendant but then not dropping out and Mitel advised to set the disconnect timer to 100ms. Had no problems since

 

[aboola]

has same problem , the public switch provide reverse polarity on disconnect any suggestion?

 

[dryaquaman]

I've seen this happen a lot in the "old days". What would happen is an analog phone would dial a number, hear a busy tone, hit hook switch and then dial another number, hear a busy and then hang up. What actually happened is that the user transferred an outside line to a busy tone to another outside line playing a busy. The line would never disconnect.
Depending on what the user did, because they could do this to multiple lines, the trunk would be playing MOH.

What I would do to resolve is one or more of the following:
(1) set the hook flash timers so narrow the user couldn't "accidentally" hookflash.
(2) replace the phone with a "positive disconnect" model.
(3) Interconnect restrict the trunks so you could not transfer one trunk to another.
(4) Train the user doing this (this never worked).
(5) Fix the Circ descriptor so when a trunk sent a disconnect signal it would actually disconnect. - This doesn't help when a user transfers a line listening to a busy signal to another line listening to a busy signal.

Dry Aquaman