Auto Attendant - Just doesn't want to let go!

[flipdee]

Hey everyone, so initially I thought it was the dreaded PSTN disconnection detection problem I was having on my OBi110's. I'm in the UK so I played around with all the recommended settings.
However I don't believe it is the above, the symptoms are as follows.
If I call a OBi110 on the PSTN Line using an AA white listed number, i.e. AA is set to answer it after the specified time, this works fine.

However if I hang up without selecting an option AA keeps the call connected for another 60secs. Infact it evens makes it through to the ring through to Phone port.

This obviously keeps the PSTN line off hook for the duration for 1min and is quite annoying.
Does anyone have any thoughts on how to get round/fix this problem.

I have tried specifying NumberOnNoInput = (NULL) i.e no number but this just seems to reduce the duration to around 45secs.

I'd probably even settle for reducing AA's messages to 1 instead of repeating 3 times, at least then it should be a very short call.

Many thanks for your help with this,

flipdee

[Stewart]

The UK uses a steady 400 Hz tone to signal disconnect, but the OBi admin guide doesn't say how to code that.  Try Physical Interfaces -> LINE Port -> PSTN Disconnect Detection -> DisconectTonePattern
400-30;5 or
400-30;5;()

Also, there may be a CPC, but of short duration; try Physical Interfaces -> LINE Port -> PSTN Disconnect Detection -> CPCTimeThreshold
200

If no luck, call into the OBi on the Line port, answer on the Phone port, start recording audio (e.g. with computer mic held to phone earpiece) and hang up the calling phone.  Post first ~20 seconds of recording here.

[flipdee]

Hey Stewart,
Thanks a lot for your reply.
I tried your suggestions but no luck sadly.
I've attached a recording of the disconnect tone.
First blip is me hanging up (calling from a cell phone) then the disconnect tone only lasts that duration (i keep the phone attached to the phone port off hook beyond the end of the tone.

Thanks again for your help with this one.

flipdee

Oh yes, I nearly forgot, apologies for the background noise, sadly my obi110 is in my "server room" if this noise is a problem let me know and i'll relocate it temporarily and re-record.
Thanks!

[Stewart]

There is no noise issue on the recording.  I am assuming that at the end of the recording, the OBi had not yet hung up the Line port.

The two clicks 400 ms apart sure smell like a CPC to me.  Is there a PBX or other device between PSTN and OBi that might be blocking it?  Confirm (by logging into the OBi directly) that for the Line port, DetectCPC   
is enabled and CPCTimeThreshold is set to 200.

Next, I don't know why the disconnect tone (which is indeed 400 Hz and lasts 6 seconds) is not being seen.  For DisconnectTonePattern, you might try 400-30;8;(6+4) or 400-30;5;(6+4)  If it still isn't detected, perhaps Obihai support could tell you how to make the device detect a steady disconnect tone, if it's possible at all.

Finally, you might try setting CPCTimeThreshold really low, perhaps to 50 -- this may cause issues on outbound calls or upon anwering, but maybe you'll be lucky and it will work.

[flipdee]

Hi Stewart,
That's again for your further thoughts on this.
I tried adjusting the disconnect tone however this made no difference.
I have found out through testing that if CPCTimeThreshold is set to 149 or below it works, 150 or above it doesn't.
Does this make any sense and if left at 149 do you think this will effect outgoing calls or cause any other problems?
Cheers,
flipdee

[Stewart]

The timing of both CPC and other interruptions of loop current can vary a little, and there is also some measurement error.  So, I recommend setting a lower value, e.g. 100, and confirming that you don't get any unwanted disconnects.

Unwanted disconnects might occur:
1. When dial tone is started.
2. After dialing out, when the call is connected to the PSTN trunk.
3. When the called party answers.
4. On incoming, when the OBi answers the line.

If you can get past all of the above with CPCTimeThreshold at 100, then set a value of 125 and you should be fine.

[flipdee]

Hi Stewart,
Thanks again for your help on this one.
I tried re-configuring another of my obi110's at another UK location, I had to adjust it exactly the same way to get the disconnect detection to work.
When I get a bit of time i'll stick it to 100 and do a lot of call reliability testing and then hopefully keep the 125 setting as you suggested.
I've submitted a support request so it will be interesting to see what/if any sugguestions come back.

Cheers,
flipdee