Re: Hook flash on connected call not working

Kjaslow11 · ‎01-26-2018

Hi. I've got a Uniden DECT wireless phone and an SPA112. I'm trying to make call waiting and 3-way calling work. I've isolated my problem to the processing of the hook/flash from the handset. As part of my troubleshooting, I tried receiving a call-waiting call from the base on speakerphone. If I hit flash a few times, it eventually picks up the call. Same deal with 3-way calling...if I button-mash the flash button while on a connected call, I'll eventually get the dial-tone for the second call.

I'm not certain if I've isolated the right settings on the ATA for this. I've got Hook Timer Min at 0.1 and Hook Timer Max at 0.9. Not sure if these are relevant to connected calls. If I were to make a guess, I think my phone is sending the flash for too short a duration, and it's just not recognized by the ATA as a flash. Anyone got any ideas if there's a way to make the SPA112 more sensitive to the flash? I'm also asking Uniden if there's any way to control the flash duration on the phone.

Thanks.

David30 · ‎07-13-2019

I also have this problem. The SPA112 is running SR1 and the 'phone is a fairly recent Uniden wired model. This has otherwise been running well for almost two years.

Pressing the flash button for any reasonable time fails to park the current call or have any other result (the caller remains connected).

Regards,

David

David30 · ‎07-13-2019

Having just reported I have the same problem, I've now just found the solution!

I searched the manual for references to "hook" "flask" "hold" etc., and found a parameter "Hook Flash Tx Method" in the Line 1&2 configuration. The user manual states (underlines are mine):

"Select the method for signaling hook flash events: None, AVT, or INFO. None does not signal hook flash events. AVT uses RFC2833 AVT (event=16). INFO uses SIP INFO with the single line signal=hf in the message body. The MIME type for this message body is taken from the Hook Flash MIME Type setting. Default setting: None."

I have set this parameter to INFO because that's how the DTMF signalling method is set; it seems to work best.

Regards...

Kjaslow11 · ‎07-13-2019

Interesting. I hadn't even thought about this for some time now. Without applying any changes, I just did a test and was able to switch between the lines using the flash button on my Panasonic phone connected to my SPA112. There is only 1 line configured, and when I look at the settings for Hook Flash Tx Method for Line 1, it's set to 'None' still. Yet the flash button on the phone did accept the incoming call waiting call, and I could switch back and forth between the calls. I know that's not a huge help to you - other than to call into question whether the Hook Flash Tx Method is the culprit or not...

Just to test, I tried setting Hook Flash Tx Method to 'INFO' and tried again, and was still able to switch lines. I'm not entirely sure what any of this means, other than this setting doesn't seem to affect my ability to switch lines either way...

David30 · ‎07-14-2019

That's interesting, and I'll keep it in mind. However the book states quite explicitly that "None does not signal hook flash events" which sounds logical for "Hook Flash Tx Method"

Perhaps there's some method whereby a phone can independently signal a hook-flash, and I'm wondering whether your Panasonic phone supports such an option but my Uniden phone doesn't. https://community.cisco.com/t5/collaboration-voice-and-video/understanding-sip-dtmf-options-supported-by-cucm/ba-p/3107307 lists one in-band DTMF signalling option which would pass transparently through the ATA and could then be actioned further upstream.

Regards...

David30 · ‎07-14-2019

This is not quite the whole story.

The default value of the "Hook Flash Timer Min" parameter is 0.1 minutes and the maximum is 0.9 minutes. https://support.8x8.com/ notes these values are wrong and suggests 0.02 and 0.9 respectively.

The user-manual states the min & max. ranges as 0.1-0.4 seconds and 0.4-1.6 seconds.

Better values may be 0.01 minimum (0.6 sec) and 0.05 maximum (3.0 sec).

These are outside the ranges stated in the manual, but seem to work. The ATA appears to multiply the set values by 60 but not enforce the specified range limits.

This is a bug which should be fixed IMO.

Limited testing indicates flash now reliably allows me to hold a call while I call a third party, and the held party hears music. However I don't think I can pick up a waiting call.

David