Disconnect Tone Tweaking - Solution

[myridom]

Today I am a happy camper...

I have finally figured out the disconnect tones generated by my NEC PBX, so that the PSTN line is dropped correctly.

For this I used 2 tools, Sigview and Sony Soundforge.

First off, I got the disconnect tone by accident after making a test call to broadvoice voicemail. And since my Sipura 3000 didn't disconnect after I hung up, the voicemail recorded the disconnect tone. This tone can be found on my original post: http://voxilla.com/forum-viewtopic-t...dedcb2d40.html

After hunting around the internet for a few hours and tinkering, I found Sigview. http://www.Sigview.com Which is some sort of signal/tone analyser.

I took the wave file from broadvoice and loaded it into Sigview. Then used the FFT (not sure what that stands for) tool to see the frequency. To find out the frequency, put the mouse at the top of the spike and look at the X coordinates. This is the frequency on the graph. (see attachment left side of picture)

For mine the signals were 472 & 621. And I think the norm being 480 & 620. OK, that is close to the specs..

Then I loaded the wave into Sony Soundforge, although I probably could have worked with Sigview and figured this out, but I already use Soundforge and knew what to look for. For this I just highlighted a section of the signal and looked at the time. 0.492 seconds on, 0.51 seconds off.
(see attachment right side of picture).

BINGO!!! My default disconect tone string was too short.
I had it as the default: 480@-30,620@-30;4(.25/.25/1+2)
With the .25 being the time the tone is on and off. Since Soundforge told me it was 1/2 sec each it needed to be: 480@-30,620@-30;4(.5/.5/1+2)

Somewhere here in the forum I saw this formula for the disconnect tone, so it helped to explain what I needed to know:
frequency1@dBm,frequency2@dbm,...;times_to_repeat( seconds_on/seconds_off/tones_to_use)

So with some final tweaking of the frequency and the new time on and off, I came up with this string which seems to work for me..

Disconnect tone: 472@-30,621@-30;4(.5/.5/1+2)

I hope this helps anyone else out there who may have run into this problem and doesnt have access to real tools to diagnose this.

MyridoM

[deavod]

Wow, that's some great detective work

[myridom]

Presents and gadgets are the only things found inside "the box". So you need to think outside of the box to use them... hehehe
I guess this need to be my SIG from now on..LOL

[mberlant]

Sigview was a great find. I will put it in my tool box.

Your assumptions to use 480 and 620 were also sensible in this context. You should probably use them and see if it works as well.

FFT stands for Fast Fourier Transform, a term I haven't used in almost 30 years (and never in real life until now).

One misconception that I also had was the units of measure for the 4(...) parameter. It is seconds, not cycles. When each cycle takes one second it is easy to make that mistake, especially since there is no documentation published.

[marner]

As we seem to have a lot of posts regarding problems detecting tones, I would suggest that this solution be made a sticky.

[mberlant]

That sounds like a good idea.

[yytel]

Could someone please help me to find out about my disconnection tone? I could not get anything out of sigview.
The wav file is attached.
Thank you in advance.

[tag]

HI

I have an NTL analog line (UK) and an anlaysis of the disconnect tone (using sigview) is showing a 400Hz tone at about -20db for 6 seconds. However, I've tried all sorts of variations on the tone plan but to no avail. As best as I can guess the plan should look something like this ;-

400@-19;6(6/*/1)

Any observations??

How do you, or indeed can you, set a plus/minus accuracy level for these plans? In my case the thing doesn't need to be particularly accurate - "listen for a buzz at around 400 and drop the line!!!" is all I want to do...

Tag





Best

Tag

[herman]

This might be better for UK :-)

Disconnect Tone: 400@-30,400@-30;2(.35/.35/1+2)

[monty141]

[quote="tag"]HI

I have an NTL analog line (UK) and an anlaysis of the disconnect tone (using sigview) is showing a 400Hz tone at about -20db for 6 seconds. However, I've tried all sorts of variations on the tone plan but to no avail. As best as I can guess the plan should look something like this ;-

400@-19;6(6/*/1)

Any observations??

Hi,

I am experiencing the exact same problem as you. My PSTN service is with BT who also use the 400hz disconnect tone. My Disconnect Tone I've tried (without success):

400@-30;20(*/0/1)

I've tried varying the duration without any luck.

In my SPA3000 Info page, the reason for the last PSTN Disconnect is always "PSTN inactivity" even though I have the CPC set to UK-regional suggested settings!

Does anyone have this working here in the UK with a BT PSTN?
Best regards,
Monty