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capture PSTN parameters for FXO disconnet

Hi,

I am facing the FXO disconnet issue in UAE, I have the disconnetc parameters but these parameters are not solving the problem, is there any way to capture the disconnect tone parameters.

Regards,

1 ACCEPTED SOLUTION

Accepted Solutions

Re: capture PSTN parameters for FXO disconnet

Hi Mohammad,

There isn't a command to do this, but you can do it with free, available tools.

Required:

Packet capture in G.711 of problem

Wireshark ( http://www.wireshark.org/download.html )

Cool Edit Pro or Adobe Audition (Shareware, here's a link I found: http://www.toggle.com/lv/group/view/kl36218/Cool_Edit_Pro.htm )

Getting the packet capture:

SPAN is easiest. Otherwise, you can get it from the back of your phone. In CUCM, on the phone page, enable Span to PC Port and reset. In CME, use this command under telephony-service and reset "service phone spanToPCPort 0". On the phone you can confirm: Model Information -> Ethernet Information -> Span to PC Port should be "Yes".

Getting the packet capture:

Start your packet capture. Place call from FXO to IP phone. Hang up on the FXO and listen to the disconnect tone for 10 seconds. Stop the packet capture.

Getting the packet capture into an audio stream:

If the blue voice packets show up as UDP instead of RTP, you'll need to decode them. Right click on one of the UDP packets, select "Decode As". In the list, you should choose RTP.

Then go to Statistics->RTP->Show all Streams. You should click on the stream from your gateway IP address to your IP phone. Click "Analyze Stream".

This will show you the stream analysis from the gateway to the IP phone. At the bottom you should be able to click "Save Payload". You need to choose the forward direction, and .au as the format. Then choose the filename.

Determining your frequencies and cadence:

Open the audio file in Cool Edit. You should be able to listen to the stream and confirm it's what you heard from the gateway. Skip to the part where the disconnect tone is. Highlight the part that is the tone.

Go to Analyze-> Frequency Analysis. This will give you the Time Domain of the audio you have selected. For DTMF and disconnect tones, you should see 2 distinct spikes in the frequency domain. Hover your mouse over the tip of the spike, and you will find out the frequency. For a disconnect tone, you should have either one or two tones, record these values.

To determine the cadence (on/off timing), you need to zoom in on the tones. Select only the 'on' part of the tone - the part you can hear. Go to View->Display Time Format->Decimal.

In the lower right hand corner, it should give you the "Length 0:00.xxx". This value is in milliseconds and is what you'll use in your custom disconnect class. Record this - this is your ON cadence.

Next, select the empty area between your first and second tones. Look towards the Length field again and record this value, this is your first OFF time.

Continue to do this for each ON/OFF until there is a pattern.

You will then enter this into your router:

voice class custom-cptone

dualtone disconnect

frequency

cadence ...

Note: You want to use 3 or more values here for best results.

On your FXO port, you will want a configuration similar to:

voice-port 0/0/0

supervisory custom-cptone

cptone

supervisory disconnect dualtone mid-call

connection plar

Hope this helps.

-nick

17 REPLIES

Re: capture PSTN parameters for FXO disconnet

Hi Mohamed,

For the disconnect signal for the FXO

It is requested from the Telco to be activated

You will ask them to activate " the reverse polar " for your line

القطبيه العكسيه

Wish this be helpful

Salam :)

Community Member

Re: capture PSTN parameters for FXO disconnet

Hi Haytham,

thanks for your reply, did you try this in UAE.

Regards,

Mohammad

Hall of Fame Super Gold

Re: capture PSTN parameters for FXO disconnet

The arabic writing looks cool, I have a feel that a lot more of it would be needed sometime.

Re: capture PSTN parameters for FXO disconnet

Hi Mohammad,

There isn't a command to do this, but you can do it with free, available tools.

Required:

Packet capture in G.711 of problem

Wireshark ( http://www.wireshark.org/download.html )

Cool Edit Pro or Adobe Audition (Shareware, here's a link I found: http://www.toggle.com/lv/group/view/kl36218/Cool_Edit_Pro.htm )

Getting the packet capture:

SPAN is easiest. Otherwise, you can get it from the back of your phone. In CUCM, on the phone page, enable Span to PC Port and reset. In CME, use this command under telephony-service and reset "service phone spanToPCPort 0". On the phone you can confirm: Model Information -> Ethernet Information -> Span to PC Port should be "Yes".

Getting the packet capture:

Start your packet capture. Place call from FXO to IP phone. Hang up on the FXO and listen to the disconnect tone for 10 seconds. Stop the packet capture.

Getting the packet capture into an audio stream:

If the blue voice packets show up as UDP instead of RTP, you'll need to decode them. Right click on one of the UDP packets, select "Decode As". In the list, you should choose RTP.

Then go to Statistics->RTP->Show all Streams. You should click on the stream from your gateway IP address to your IP phone. Click "Analyze Stream".

This will show you the stream analysis from the gateway to the IP phone. At the bottom you should be able to click "Save Payload". You need to choose the forward direction, and .au as the format. Then choose the filename.

Determining your frequencies and cadence:

Open the audio file in Cool Edit. You should be able to listen to the stream and confirm it's what you heard from the gateway. Skip to the part where the disconnect tone is. Highlight the part that is the tone.

Go to Analyze-> Frequency Analysis. This will give you the Time Domain of the audio you have selected. For DTMF and disconnect tones, you should see 2 distinct spikes in the frequency domain. Hover your mouse over the tip of the spike, and you will find out the frequency. For a disconnect tone, you should have either one or two tones, record these values.

To determine the cadence (on/off timing), you need to zoom in on the tones. Select only the 'on' part of the tone - the part you can hear. Go to View->Display Time Format->Decimal.

In the lower right hand corner, it should give you the "Length 0:00.xxx". This value is in milliseconds and is what you'll use in your custom disconnect class. Record this - this is your ON cadence.

Next, select the empty area between your first and second tones. Look towards the Length field again and record this value, this is your first OFF time.

Continue to do this for each ON/OFF until there is a pattern.

You will then enter this into your router:

voice class custom-cptone

dualtone disconnect

frequency

cadence ...

Note: You want to use 3 or more values here for best results.

On your FXO port, you will want a configuration similar to:

voice-port 0/0/0

supervisory custom-cptone

cptone

supervisory disconnect dualtone mid-call

connection plar

Hope this helps.

-nick

Re: capture PSTN parameters for FXO disconnet

woy!!!!!!! Extremely helpfullllll

Community Member

Re: capture PSTN parameters for FXO disconnet

thanks a lot Nick for your brilliant solution, this has solved my problem.

Reagrds,

Mohammad

Community Member

Re: capture PSTN parameters for FXO disconnet

Excellent!

Community Member

Re: capture PSTN parameters for FXO disconnet

Hello nicmatth,

I was try another method:

1. Record the voice (disconnect tone) from ipphone (loud-speaker) using microphone on PC.

2. open recoding file using Cool Edit.

3. go to "Show Frequency Analyzer". The result is 420.11 Hz (G#4 +19). I'm using this number for Freq1 and Freq2.

4. for Cadence, i'm using Your Method.

Problem:

FXO still not disconnected.

Question:

1. is it possible using this method for looking frequency ?

2. is it need to configure "voice class dualtone-detect-params " ?

Thanks.

Re: capture PSTN parameters for FXO disconnet

1. If you have a single frequency only enter one frequency for the disconnect tone.

2. voice class dualtone-detect-params are simply a way to change some default parameters for greater flexibility on matching. There are defaults that work pretty well, and most implementations probably don't need to change these values. They can be quite helpful in troubleshooting though.

-nick

Community Member

Re: capture PSTN parameters for FXO disconnet

Topology:

Siemens_Hipath4000(analog ext)---(FXO)3845(MGCP)---(MGCP)CUCM---IPphone.

Problem:

-Ext Siemens dial FXO.

-IP phone answer.

-Ext Siemens on-hook.

-IP phone hear Disconnect tone. But FXO still off-hook.

1. I'm confuse read Frequency Analyzer. How to know is dual or single frequency ?

2. after we set "voice class custom-cptone" in CME and apply to interface. Is it need to shut & no shut voice port / reload CME / all interface must be applied "Supervisory custom-cptone" ?

Re: capture PSTN parameters for FXO disconnet

'spikes' in the frequency analysis tell you how many they are sending.

You also need:

supervisory disconnect dualtone mid-call

-nick

Hall of Fame Super Gold

Re: capture PSTN parameters for FXO disconnet

Try 425 Hz, that is what Indonesia is known to use.

Community Member

Re: capture PSTN parameters for FXO disconnet

I was try 425hz, still not working.

Community Member

Re: capture PSTN parameters for FXO disconnet

Nick Thank you very much for this wonderful solution.

Obtaining the disconnect tone info from the carrier is a painful process, with this solution its not needed anymore.

Thanks again

Community Member

Re: capture PSTN parameters for FXO disconnet

Hi Nick!

I couldn't catch up about how to get the frequency and cadence using Cool Edit Pro. I would appreciate if you could provide the screenshot of Cool Edit Pro?

Thanks.

Community Member

Re: capture PSTN parameters for FXO disconnet

Hi,

Please check this link for detail steps with screenshot. Hope this help

http://ciscoflair.blogspot.com/2009/05/cisco-fxo-disconnect-issue.html

Community Member

Thanks, this is great. solved

Thanks, this is great. solved my problem

just for reference

KSA (STC Lines) 

on   352
off  347

453  HZ

 

Regards.

Regards, Mohamed Helmy
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