LMT analog trunks MCD5.0 1

[danramirez]

Guys,

We recently installed a CXi controller (Not CXi II), MCD5.0, in Dominica and connected 3 analogue trunks from Cable and Wireless.

Customer reported echo when calling from IP phones to outside over analogs. Also, lines are not being disconnected when people from outside leave a voicemail.

I assume that first of all we should run Line Measuring Tool, any idea how to do this, I find Help online a bit confusing.

Also, how do I set the 3300 to detect the busy tone, so lines disconnect after far end hangs up.

Regards,

Daniel

 

[IrwinMFletcher]

You'll first need the numbers from C&W for their milliwatt and silence numbers, and put those into your Trunk CD form. Then run the Line Test.

This will give you the recommended settings based on the trunk line you're testing.

 

[TNUV]

Hi

I got the exactly the same problem, i did run the LMT in loop back mode and result says [ YELLOW - ERL -17.945 ].

I tryed evey tip in the book and no result, i think that changing the country may help to fing the right impedande.

Playing with audio inhibit and fake answer does not help.

Mitel 3300 Rel 4.1 SP1.

6 - LS analog trunk.

29 - 5340 IP phone

impedance : national complex / short ( recomanded setting from the LMT ).

Any ideas. Thanks

 

[wireman50]

Line disconnect with VM problem is a setting on the system. You need to get Clueless & Witless to tell you the diconnect clear time and set a similar one in the LS settings.(some are set to ~100msec, others are set to as long as 800 msec....)

Echo sounds like a latency problem so I wonder how the lines are being delivered....possibly by SIP and thence to you as analogs via an ATA?

I did warn you.....

 

[wireman50]

Setting is in Trunk Circuit descriptors.



Try the balance Network settings in Analog trunk forms for the echo problem.

 

[wireman50]

Might also be worth a peruse at page 49 et seq in The Hardware technical manual....in conjunction with C&W

 

[TNUV]

I'm located in Tunisia and my CO provider does not use ATA, the trunks are pure analog. i tried every possible combination for the balance Network settings for both CO and analog trunk form.

since there no recommended setting for my location i used France instead. ( HTRM Page 49 ).

 

[IrwinMFletcher]

There is no point in changing the settings, if you have successfully run the LMT and it recommended complex/short, then that's what you need to use, and even then it is a suspect level (yellow warning). The LMT runs through all of the settings and recommends the best one.

Bottom line is that the trunks suck.

 

[TNUV]

humm the think is when i remove an analog line from the mitel and use it with an simple analog phone, the trunk work perfectly.

damn this is frustrating.

 

[wireman50]

Yup, but you have anlog to VoIP to deal with and TBH we have found that the Mitel sucks with analog lines in general.....maybe thats just us though.(especially when the customer reads that you can forward calls external.....)

 

[IrwinMFletcher]

If you mean that if you take the trunk line and instead of connecting it to the controller, you plug an analog phone onto it, then yes obviously that works.

You need to understand the nature of echo why you hear it. When you use the analog phone, the echo is still there. Actually there is MORE echo than when you connect the line through MCD because there is no echo canceler in the path. The issue is the time delay. In order to go from a TDM system to a packet based system, you introduce delay. It's this delay that lets you 'hear' the echo. On a pure TDM system, the delay is short enough that the echo sounds like side tone. That's why even on pure TDM systems, if you call long distance, the SP will put in an echo canceler because the time delay increases enough that you can hear the echo.

Depending on your platform type, you can try to switch between the hardware and software based echo cancelers, they have different characteristics. One may be better than the other for your environment.

 

[TNUV]

Hi Again

So after 1 week of playing with the 3300 CX II, i found the best setting for my country, here bellow my results :

---------------------------------------------------------------------------------------------------
* changing the country does not any effect on the echo, but will affect the quality of the line.
---------------------------------------------------------------------------------------------------

So the best results was to use : (recommended from both LMT and Personal cheking )

Country : France ( they use the same impedance and balance as Tunisia )
Balance Network Setting : National Complex
Trunk Category : Short
AC Impedance : National

So far so good but when comes to answer supervision i got some disturbing results for 4 possibles combinations :

------------------------------------------------------------------------------------------------------------------
Fake Answer Supervision after Outpulsing : No
ignore Answer Supervision : No
Release Supervision Expected : No
Audio inhibit Until Answer Supervsion : No

--> Echo All the time and two ways audio.
-------------------------------------------------------------------------------------------------------------------
Fake Answer Supervision after Outpulsing : No
ignore Answer Supervision : No
Release Supervision Expected : No
Audio inhibit Until Answer Supervsion : Yes

--> No Echo All the time and one way audio.
-------------------------------------------------------------------------------------------------------------------
Fake Answer Supervision after Outpulsing : Yes
ignore Answer Supervision : Yes
Release Supervision Expected : Yes
Audio inhibit Until Answer Supervsion : No

--> Echo For about 5 sec and two ways audio.
-------------------------------------------------------------------------------------------------------------------
Fake Answer Supervision after Outpulsing : Yes
ignore Answer Supervision : Yes
Release Supervision Expected : Yes
Audio inhibit Until Answer Supervsion : Yes

--> No Echo All the time and two ways audio, But sometimes the caller can't be heard for about
2 to 3 sec from the far end ( this problem happens randomly whatever you call a land line or a mobile.
-------------------------------------------------------------------------------------------------------------------

* So after trying every tip in the book, i got a conclusion Mitel sucks with Analog trunks.

@ IrwinMFletcher : when using analog phones on mitel they work perfectly !!!

 

[TNUV]

Guys finally found the solution it's was so simple but hard to find :

-------------------------------------------------------------------------------------------------------------------
Fake Answer Supervision after Outpulsing : Yes
ignore Answer Supervision : Yes
Release Supervision Expected : Yes
Audio inhibit Until Answer Supervsion : No

--> Echo For about 5 sec and two ways audio.
-------------------------------------------------------------------------------------------------------------------

using those setting was the right choise and by setting the option Drop digit receiver for outgoing audio before answer supervision to Yes. the problem was solved , no more echo, delay.

This f***** nightmare is over.

Thanks anyway for your help.

 

[IrwinMFletcher]

Good to hear that it worked out for you.

Basically what you are doing is forcing the audio connection to be established while you're listening to ringback. I'm still a little surprised this works since A. the EC still needs some input to locate the echo (you need to be talking on the IP side, although correlated noise may work), and B. the impedance of the trunk should change (although maybe just slightly) once it switches to talk-state.