3300 Locked Analogue Lines

[AndyMR2]

Hi Guys,

Is there a command in the Mitel system to clear down an analogue line that is showing as busy?

I have two analogue trunks which are stuck and our support company is telling me to restart thet system which is something I would prefer not to do.

  Location    | Device               | State         |  Owner  | ID   |Status   
----------------------------------------------------------------------------   
 2 1  1  10   | LS on Embedded ASU   |Busy           |Call Proc|7 04DC|Wait     
 2 1  2   5   | LS on Embedded ASU   |Idle           |         |      |         
 2 1  2   6   | LS on Embedded ASU   |Idle           |         |      |         
 2 1  2   7   | LS on Embedded ASU   |Busy           |Call Proc|3 04A7|Wait     
----------------------------------------------------------------------------

Regards

[sarond]

Can you disconnect them from the rear of the controller? Maybe this will clear them down.

[AndyMR2]

Unfortunately I'm about 250 miles away from them. 

I can reboot it but I'd have to take the whole site down for 15 mins while it restarts. We're open 24 hours a day so there's never a great time to reboot the controller. I was hoping there was some way to force the line clear on the controller as it's definitely not on a call.

Thanks

Andy

[jrg0852]

Busy X-X-X-X, where the X's are the PLID. Do a STATE to verify it is busied out. Then RTS X-X-X-X to return to service. Let us know. Thanks.

[ralph]

It would appear that your trunks are getting locked together.
You'll need to fix that or it will just keep happening.

If these trunks are connected to a CO then you may be able to adjust your disconnect timers to resolve it.
If they're connected to another PBXs' analog station ports then you'll need to block trunk to trunk access.

In the short term do what jrg0852 suggest.

Ralph

[tomj]

You have to be careful when allowing LS analogue trunk to analogue trunk connection as these do not necessarily support “Disconnect Supervision” unlike digital or IP trunks particularly when outside NA.

The embedded LS and ASU LS Trunks will support the following clearing signal:

Line Break -  CO Trunk Circuit Descriptor default value of 500mS

Line Reversal -  an optional CO Trunk Circuit Descriptor value

“Busy” tone disconnect supervision - used in Europe, Middle East and Africa

You need to establish what disconnect method is being used, the first two are straightforward. Assign a “new” CO Trunk Descriptor and try the two options, you may need to change the disconnect timer.

The latter is tricky as you need to confirm the disconnect tone frequency, level and cadence before configuring (system wide) CO Detection. Unfortunately, if you use Auto-Attendant or trunk to trunk connection you will need to complete this or get to know Busy/RTS.

Do you have a recording of the tone?

Good Luck!

[AndyMR2]

Hi Guys,

Thank you so much for the help.

We're having a few issues using the PSTN trunks with Mitel. Our support company want us to move from PSTN to ISDN or SIP to fix it but this will be a costly exercise for us as we get special charitable rates on PSTN lines.

The system isn't connected to another PBX and we've disabled the ability to do an outbound call transfer. Is there any other way the lines can get locked together?

Unrelated but another issue we are having is intermittent echo on the lines. We've had all of the lines tested by our carrier and they say they're clear, we've also tested the internal wiring which also seems ok.

Our old NEC system had neither of these problems and I'm starting to regret the switch.

[martyn]

It's a common problem here in Australia, and like it has been reccomended, the best bet is to switch to ISDN or better again SIP. The charity prices do make it a hard sell though, so I can see your point :-)

The other thing that can sometimes cause the lines to lock is transferring to voicemail, as it doesn't always clear the call down correctly when the message has been left and the caller has hung up.

There is a number that you can call that will test the line and give you back the recomended settings for your analogue trunk. Just trying to find the number though.
Do you have full system access to the 3300 to look at the trunk settings?

[AndyMR2]

Hi Martyn,

Yup I have full system access. It's funny, all the techs I talk to say they haven't touched a PSTN in years, we've got hundreds of the bloody things!

Regards

[martyn]

Yep it is common for charities to be stuck on analogue lines as they cost near nothing at all per month. If you make enough outbound calls though then moving to SIP can be an equivalent spend to the analogue lines.

Try following the steps in the attached spreadsheet and see if that helps with the line issues.

[AndyMR2]

Thanks Martyn that's really helpful.   

I'll report back tomorrow with the results.

[tomj]

Guessing your trunk provider is using "busy tone" disconnect and not line break (the deafult setting).

To get your trunk lines to disconnect properly you MUST establish the disconnect signal or tone.

Trying calling the provider, ask them to confirm the disconnect signal, if it is line break or line reversal then you may need to amend the CO Descriptor if they are using tone disconnect then you will need to take a look at CO Tone Detection.

[martyn]

If the test that I attached earlier doesn't help, then can you post some screen shots of your analogue trunk settings and then they can be compared to see if they are set correctly. In particular CO Tone detection, and trunk circuit descriptor.

[sarond]

Martyn,

Do you mind if I compare my CO Tones for Telstra.

[tomj]

Your CO Descriptor - Calling Signal=Disconnect (the default), I can't see the timer but the deafult is 500mS.
This means your trunk is expecting a line break of 500mS or above before it will disconnect the trunk.

You can try changing the Calling Signal disconnect timer or try Reversal but I would guess the far-end is sending a "busy tone".

Connect a test-butt telephone across the copper line and monitor the line for the clearing signal, if you hear a tone, then you need to confirm the frequency, cadence and levels. Once you have these you will need to enable and configure CO Tone Detection. I've updated your excel document with example values but do not have a screen shot unfortunatley. Establishing the frequency is trick but there are ways and means.