[Walford58]

Hi
I've just encountered a problem on my system, and I'm not sure where to start looking.

I have an SPA9000 with SPA400, which is handling only the vm, and an SPA3102 dealing with the PSTN calls.

Everything seems to be working fine, except for a little tweaking to reduce the echo and compensate for attenuation on the PSTN line.

I was on an inbound call last night over PSTN - the first lengthy one since the system was set up, and the system dropped the call after a period of time (around 8 minutes)
The caller redialled and I used an SPA941 handset instead of the FXS-connected one that I originally answered with.
After a further period of time, the call ended again at my end. I don't know exactly how long this was, as the logging doesn't retain that information - only start of call - about 7 minutes. I redialled from my handset and was immediately connected to the caller again, who was only aware of a problem as he had heard some DTMF tones. Obviously his end of the call was still up. This happened again after another 16 minutes, and again by redialling his number I was connected, and he hadn't even noticed me missing that time.

As this is not a regular pattern, it's difficult to predict the circumstances, but it has never occurred before on any of the lines even though there have been significant VoIP calls on those, so I suspect some relationship with the SPA3102.

As per Humba3's recommendations, the SPA3102 is not registered to the SPA9000.

Does anyone else have similar examples of this behaviour, and have you identified when it might occur?
Are there any suggestions what to look into to find out whether this is an inherent problem?
I am still on firmware 5.1.8 on the SPA9000 and 5.1.7 on the SPA3102.

Man thanks

Pete

[humba3]

I've heard that before some time ago.. when logging was turned on all the way on the SPA3k, the log showed that the box detected a PSTN disconnect and terminated the SIP call leg. I do not recall though if the problem was ever fixed.. but looking at those logs should at least tell us why the call is dropped and who initiated the drop (at least in the eyes of the SPA3k).

[Walford58]

Originally Posted by humba3

I've heard that before some time ago.. when logging was turned on all the way on the SPA3k, the log showed that the box detected a PSTN disconnect and terminated the SIP call leg. I do not recall though if the problem was ever fixed.. but looking at those logs should at least tell us why the call is dropped and who initiated the drop (at least in the eyes of the SPA3k).

I had another dropout tonight, and by good fortune the debug logging was enabled. Looking at the info status on the SPA3102, the call was dropped because of a PSTN disconnect tone. This is supported by the information in the syslog.

So now, where do I look?
As I'm in the UK, disconnect tone is set to 400@-30,400@-30;2(*/0/1+2)
Is it possible that this is not quite right for the line, or that I have noise on the line which is being interpreted as a disconnect, should I be talking to the engineers at BT or are there mice in my SPA3102?

I have adjusted the disconnect tone to 400@-30;4(*/0/1) in case there were two spurious tones which triggered the problem, as I read elsewhere that 400@-30;20(*/0/1) worked, but I don't want to have to wait for 20 pulses. I've also recabled the FXO back to the master socket and changed the ADSL filter to help reduce any noise.

Any other suggestions are more than welcome.

Thanks

Pete

[Walford58]

Having followed up with several more dropped calls. it appears the termination is coming from the PSTN system - or at least that is what is being detected by the SPA3102.

The log reports:
FXO:Pstn Activity Time Out
AUD:Stop PSTN Tone
FXO:On Hook
FXO:Stop CNDD
AUD:Stop PSTN Tone

The disconnection settings on the PSTN tab are:
Detect CPC = Yes
Detect Polarity reversal = Yes
Detect PSTN Long Silence = Yes
Detect VoIP Long Silence = No
PSTN Long Silence Duration = 60
VoIP Long Silence Duration = 60
PSTN Silence Threshold = Low
Min CPC Duration = 0.09
Detect Disconnect Tone = Yes
Disconnect Tone = 400@-30,400@-30;10(*/0/1+2)

I changed the silence threshold from medium to low as I wanted to reduce the sensitivity, according to the admin guide. Also I had adjusted the gain recently to compensate for too much attenuation and make the conversation audible without significant echo.
SPA to PSTN gain = 2
PSTN to SPA gain = 5

Can anyone throw some light on this? I assume I must be making changes which conflict with the PSTN parameters, but I can't see which direction to go. Also could anyone please verify the settings are OK for the UK.
Thanks.

Pete

[snoop]

Hi Pete

Just wondered whether you had made on progress on this as I am experiencing similar problems

Chris

[Walford58]

Chris
I reset the 3102 to factory default and started from scratch, but since I am using a SPA400 for vm and the 3102 was mainly for experiment and to allow the UK callerID through, I had a fallback.
Also now, I have a GSM gateway connected so all of my lines are taken on the SPA9000.
I will be looking at it again, but in the meantime, it might be worth you taking the 3102 back to basics and set it up step by step.
Mine only appeared to have problems once I started to adjust the gain.

Let us know how you get on if you have the opportunity.
Pete