PSTN calls disconnect in the middle of the call

[lucaspiller]

I got my Obi the other day, and set it up and so far things have been great. Today though I was chatting with someone and the phone hung up, I called them back and the same thing happened, I rebooted my Obi110, they called back and then the same happened again.

It happened roughly 2 minutes after the call was connected. In the call log I can see the "End Call" event happened on "PHONE1" a few times and then on "LINE1" a few times.

Any ideas what it could be, and is it possible to enable debug logging to find out what caused this?

The Obi is connected to a BT line through an extension. I've set it up for the BT configuration I have found on these forums, including the disconnect tone.

[drgeoff]

"extension" means a wired extension from a DEL (Direct Exchange Line) master socket or the 'phone line' is an extension on a PBX?   

[lucaspiller]

There is an extension from the master socket to a room upstairs. Connected to this socket is an ADSL filter with the Obi and an ADSL router (which was working fine).

EDIT:

I tested this again dialling a DID I have for work and the other way around. I put the phone on speaker next to a radio so there wasn't any silence. When dialling out after a couple of minutes the call disconnected on the "LINE" side and I heard a dial tone from the local phone. I then tried repeating it, but couldn't do so.

The levels when in a call are:

Phone
LoopCurrent 20mA
VBAT 17 V (12.0 V)
TipRingVoltage 7 V

Line
LoopCurrent 36mA
VBAT (blank)
TipRingVoltage -7 V / -8 V

[tg.voip]

I have the same problem. Looking for the expert to solve the problem.
http://www.obitalk.com/forum/index.php?topic=7630.0

[ianobi]

It looks like in both cases the OBi110 is seeing what it thinks is a disconnect signal. One approach would be to go here:

Physical Interfaces > LINE Port > PSTN Disconnect Detection

Disable all four methods of detection, that is all four parameters starting with the word "Detect". See what happens for a few days. If the problem goes away, then enable each of the detect methods that you consider useful one at a time. Hopefully, you will find which one causes the problem.

With all four disconnect methods disabled, calls should still hang up if both parties hang up. If not, then simply remove the line cord for a few seconds to disconnect the call during this test period.

[lucaspiller]

Hey ianobi thanks! I also found this thread that describes the same issue and says it was fixed by turning off "DetectFarEndLongSilence" I'll try that and see if that helps, if not I'll try the other options in that section as you say.

http://www.obitalk.com/forum/index.php?topic=6678.0

It would be great if the Obi actually logged what caused an event to happen, then I would instantly know what the cause is. It seems that logging isn't very well thought out on this device, I have a bit of a complicated SIP setup so I setup syslog and turned on SIP debugging. I got messages saying the device booted up, but no debugging messages for SIP which was very useful In the end I had to use ngrep.

[ianobi]

I agree with your comments regarding logging. With physical lines it's pretty much trial and error.

I'm also in the UK, but I don't use British Telecom. The only PSTN Disconnect Detection I'm using just now is CPC. CPC in the UK is much shorter than the North American default setting in the OBi (450ms). In the UK it can vary between 90ms and around 120ms. I have mine set to 100ms and it works fine.

[lucaspiller]

Just to update: Disabling DetectFarEndLongSilence fixed the issue of disconnecting in the middle of calls. However after that I kept getting lots of 'blank' calls where there was nobody there.

The main reason why I got the Obi was to block automated callers. I had it setup to route withheld numbers to the attendant, and then have them press 1 to continue. For some reason the Obi wasn't detecting the disconnect, but was interpreting it as the user pressing 1, which resulted in these 'blank' calls. Changing CPC from 450ms to 100ms seems to have fixed that.

[MarkObihai]

I've attached a configuration xml file See post below for updated file (enclosed in a .zip) that you can upload to your OBi110.  This contains all UK local settings, progress and ring tones plus digit maps.

This is quite new and will be uploaded to http://www.obihai.com/docs-downloads  (Where you'll find the UK config file for the rest of the OBi products)

If you fancy some additional reading, there are also quite a few posts on https://www.ukvoipforums.com about configuring the OBi for use in the UK.

[drgeoff]

I've attached a configuration xml file (enclosed in a .zip) that you can upload to your OBi110.  This contains all UK local settings, progress and ring tones plus digit maps.

This is quite new and will be uploaded to http://www.obihai.com/docs-downloads  (Where you'll find the UK config file for the rest of the OBi products)

If you fancy some additional reading, there are also quite a few posts on https://www.ukvoipforums.com about configuring the OBi for use in the UK.

That file sets the CPCTimeThreshold to 9.  I believe that is incorrect and should be 90 (milliseconds).

[Usetheforceobiwan]

I've attached a configuration xml file (enclosed in a .zip) that you can upload to your OBi110.  This contains all UK local settings, progress and ring tones plus digit maps.

This is quite new and will be uploaded to http://www.obihai.com/docs-downloads  (Where you'll find the UK config file for the rest of the OBi products)

If you fancy some additional reading, there are also quite a few posts on https://www.ukvoipforums.com about configuring the OBi for use in the UK.

OMG, a real honest to goodness Obihai administrator the likes of which has not has been heard from in a fortnight or two...or three.  Could a Big Foot and Loch Ness sighting (on the same day!) be far behind?  Have they found Sherman yet?  I'll to contact the media..........................

Note to forum regulars:  Leave this guy alone for awhile so we don't scare him off like his predecessors.  I think you would agree it gets lonely out here not hearing from a voice from Obihai. 

[MarkObihai]

That file sets the CPCTimeThreshold to 9.  I believe that is incorrect and should be 90 (milliseconds).

You are correct - thank you for bringing that to my attention.  I've updated the file as attached.

OMG, a real honest to goodness Obihai administrator the likes of which has not has been heard from in a fortnight or two...or three.  Could a Big Foot and Loch Ness sighting (on the same day!) be far behind?  Have they found Sherman yet?  I'll to contact the media..........................

Note to forum regulars:  Leave this guy alone for awhile so we don't scare him off like his predecessors.  I think you would agree it gets lonely out here not hearing from a voice from Obihai. 

Thanks (I think?) -  I'm based in London and will try and help with regionalisation queries for Europe and Australia/NZ.