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New Member

ATA 186/188 hookflash relay

I have a Cisco 1750 connected to a PBX on an FXO port. At my remote location I have an ATA 186 with an analog phone.

I want to be able to use the "Flash" button on the analog phone to take advantage of my PBX features, but it seems the ATA 186 will not relay my hookflash event. I've tried enabling bits 6/7 with the latest firmware, but it doesn't work.

What is the recommended Audiomode configuration with DTMF in-band to enable hookflash relay? Or is this even possible?


New Member

Re: ATA 186/188 hookflash relay

Look at this Document. It has setting you can set for the Hookflash parameters. I have found that some devices are looking for shorter hook flash time. The default hookfash timer is 1000ms.

New Member

Re: ATA 186/188 hookflash relay

Sorry - should have mentioned.

This is for SIP. The article you sent was for MGCP.

I tried playing with bit 19 in the CONNECTMODE just to see, but still no go.

The ATA wants to handle the Hookflash event - I need for this to be relayed, just like a DTMF key.

Thanks and any help on this is welcome!!!

New Member

Re: ATA 186/188 hookflash relay

That would make a difference. I did send you information for MGCP.

Bit 19 for the CONNECTMODE Disables or enables the Cisco ATA to send a ringback tone to the caller.

That wouldn't make any difference in your case as you found out.

As for me Audiomode 0x00120012 has worked for me and the LBRCodec set to 0 (default is 3).

Good luck.

New Member

Re: ATA 186/188 hookflash relay

Thanks for the config.

I tried 0x00120012 and the ATA still wants to handle the hookflash and not relay the signal to my router.

Here's a quick way to determine if yours is too:

Configure a Hotline in your dialplan to a VOIP extension.

I have extension 1000 setup to connect directly to my FXO port on the router via the dialplan entry:


Now whenever I hear dialtone on the router - I press the "Flash" button on my phone & I immediately hear a busy signal. Reviewing the SIP Headers, I notice another SIP INVITE message being sent to the router. This means the ATA is not relaying the hookflash - just putting my original call on hold and tries to establish a new connection.

What I need to happen is the ATA relay that hookflash to my router directly so my PBX will be able to process the event in order to use other features.

How do I make the ATA relay the hookflash and not process it locally?

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