GPRS Socket disconnected -36

[gg50]

Hi,
when a phone is on the charger, the Tracker is instantly showing the "GPRS Socket disconnected -36" in the log. The problem is that this is causing a phone to beep every time, and it's really annoying, especially during the night time.
This issue is verified on 5800, N82 and 6650.

I have found the similar topic here
viewtopic.php?f=3&t=508&hilit=beep#p950

It is not exactly the same, and 1 year passed after, so, may be there are any newer advices to avoid these beeps ?

Thank you in advance,
G.

[jje]

@G:

I have some further questions to you:

Is the phone connected to the mobile network, when it is shows the message and beeps?

Or is the phone in offline mode?

Does it beep only once after you connect the charger or is it repeating the beep regularly?

- Jyrki

[jje]

The beeping message "GPRS Socket disconnected -36" may appear, because your mobile operator or some network router has disconnected an idle looking GPRS connection.

It may be good to have frequent data sending (like every 1 minute) to keep the GPRS connection open. Otherwise you may get unnecessary connection failures even if there is a good GSM signal. You have to test this idle connection behaviour individually in your country and in your environment.

You can adjust the data sending interval with triggers. Read more at:
http://www.aspicore.com/support/gsmtrckr/default.htm#triggers

- Jyrki

[gg50]

Yes, the phone is connected.
This message in the log appears (and phone beeps) every time, when it is trying to get and send GPS data. In my case, timers are set like this:
On startup GPS ON
Max fix wait 3
Powersave ON
Retry after 15
Time trigger ON
Time period 12
With these settings, I am receiving positions approx. every 15 minutes.

Whithout the charger the log looks like this:
Connecting IAP
GPS receiver active
Module ID xxxxx
Using Assisted GPS
My operator access point name 6
Connecting TCP socket
Connection created (IAP engine)
Connected Internet
Put GPS to sleep
No Internet connection

When on the charger:
"Charger connected
Connecting IAP 16:46:01
GPS receiver active
Module ID xxxxx
Using Assisted GPS
My operator access point name 6
Connecting TCP socket 16:46:07
Connection created (IAP engine) 16:46:07
Connected Internet 16:46:08
No Internet connection 16:53:51
GPRS Socket disconnected -36 16:53:51
Connecting IAP 16:54:57
My operator access point name 6
Connecting TCP socket
.......
repeating until charger disconnected


By the way, if logs are useful for troubleshouting, then probably it could be implemented the setting, which send the recent log file to your server.

WBR, G.

[jje]

Thank you for the thorough log information!

I think the problem is that with your mobile operator (or server firewall) an almost idle GPRS connection does not stay on as expected. GSM Tracker beeps on the unexpected connection break.

When the charger is not connected, with powersave, GSM Tracker intentionally disconnects and does not expect the GPRS connection staying on. No beeps.

Time trigger ON
Time period 12

Could you try with
Time period 1

Then, without the charger, you should receive positions approx. every 15 minutes as before.

When the charger is connected, you should now receive positions every 1 minute. This should keep the TCP connection constantly open and prevent the annoying beeping.

***

Another measure to avoid the beeping is the menu command "Packet data" / "Disconnect Internet" for the period while the charger is connected. The collected positions will stay in the output buffer and they are sent to you when you later issue the command "Packet data" / "Connect to Internet". Do this before disconnecting the charger and wait for the output buffer clearing. ("Output buffer" needs to be on in the settings.) Is this practical to you or not, perhaps?

By the way, if logs are useful for troubleshouting, then probably it could be implemented the setting, which send the recent log file to your server.

Thanks for this suggestion.

[gg50]

Thank you for the advice, I am going to try with Time Period set to 1 and update you with results ASAP.

But from my understanding, with this setting, more battery and more GPRS traffic will be consumed ? Is this correct ?

[jje]

But from my understanding, with this setting, more battery and more GPRS traffic will be consumed ? Is this correct ?

No more battery will be consumed, because without the charger the GPS is active only every 15 minutes.

But when the charger is connected, then more GPRS traffic will be generated, that's correct.
Does this cause any more costs, it depends on your mobile operator's pricing policy.

[gg50]

I am not familiar with application's algorithm, but I assume, that even when GPS is in a sleep mode, the phone's radio transmitter will be activated every minute, consuming more battery. Is this assumption wrong ?

[jje]

I am not familiar with application's algorithm, but I assume, that even when GPS is in a sleep mode, the phone's radio transmitter will be activated every minute, consuming more battery. Is this assumption wrong ?

Your assumption is wrong, from v3.16 onwards. Naturally you cannot know the internals of the application and our application logic and documentation could be clearer, I must admit. There are lots of features for many different purposes.

The powersave feature disconnects and reconnects the Internet connection in addition to cutting off and resuming the GPS connection. When there is no Internet connection, the application does not consume energy for the radio transmitter either.

With your settings above, the battery consumption interval is 15 minutes.

The "time period" value below the Trig1 tab does not activate the radio, unless there is already an existing GPRS connection. The new GPRS connection is created when the GPS is reactivated but not before.

The above is valid, when the powersave flag is on in the settings and the charger is not connected.

[gg50]

Hi, Jyrki,
the tracker is running with interval set to 1 on a charger about 3 hours. It beeps once; probably this was a sporadic network error. So, your solution is working more or less good. I'll update you, if anything interesting happen.

I think, that in order to save traffic, a new function could be added. Probably, in some cases, it will be more helpful just to ping any network address once a minute to keep a connection alive, instead of using that trigger to send full GPS data once a minute?

WBR, Gurgen

[jje]

I think, that in order to save traffic, a new function could be added. Probably, in some cases, it will be more helpful just to ping any network address once a minute to keep a connection alive, instead of using that trigger to send full GPS data once a minute?

We have considered that. On the other hand the current way maximizes the payload transferred versus the bandwidth consumed. There is some overhead in the TCP/IP protocol, so eliminating the payload would not make drastic savings to the bandwidth usage.