Can's send sms, but is billed for it multiple times

AppLee · 29 Sept 2020, 20:29

@jezek
As stanwood said, you need to be sure about your network coverage.
I had trouble a couple of times sending SMS but it was on new year's eve or with a bad connection.

A bad connection can mean that your SMS is sent correctly but the phone didn't get the acknowledge from the server. In this case the phone will try to send it again...

Keneda · 29 Sept 2020, 20:32

It hapened to me sometime grey circle forever.
But here in france we have unlimited sms/mms.
So can't tell for billing.
When i have the grey circle, i just stop message and resend.

jezek · 29 Sept 2020, 21:27

@stanwood @AppLee It's definitely not SIM card connection. I have to confess, I didn't make the cleaning of the SIM card, cause I think I can rule it out, I never had problems with mobile signal or some SIM related outage. And I made following test with full network coverage.
I choose 2 contacts:

brother: when called, it's ringing, he is picking up calls.
cousin: when called, it's not ringing, a default voice tells me to leave message after beep.

The I did fllowing acions:

Sent SMS to brother: sent successfully, immediately green and got one billing.
Sent the same SMS to cousin: message got gray with the circle. After 5-10 seconds a billing came. Doing nothing, waiting. After another 10-20 second second billing came. Deleted the still gray message. Waited some time, to ensure the billing stopped.
Sent the same SMS to brother: message got gray (with circle), got billing, than second, deleted the mesage. Tried again to send the same message, not successful either, deleted it.
Called brother: he picks up, and I asked him how many SMS he got from me. Answer was 1.
No action was performed, but after a minute or two, I got bunch of billings and brother sent me an message, that he got other 3 messages.

Maybe the carrier had som problems. But I don't think the app should try to resend unsent messages more times, when the status is not received some time (this is a speculation I made according to observation). I sent 3 identical messages to my brother in the test, but he got 4 at the end.

Note: In the process of writing this reply, I communicated with my brother and another other contact through SMS without flaws.

@Keneda Wow free SMS, what a dream. Maybe in 50 years we well have free SMS in my country too

Keneda · 30 Sept 2020, 00:03

@jezek said in Can's send sms, but is billed for it multiple times:

Wow free SMS, what a dream. Maybe in 50 years we well have free SMS in my country too

Here we have a carrier who makes you pay 2€ per month for 2h hours voice, sms and mms unlimited, 50Mo (lol...) internet (http://mobile.free.fr/)

Some other give you more voice (most of the time unlimited) and internet (5 to 20Go) for few euros more.

I know it's not the same everywhere, carriers are greedy most of the time...

lduboeuf · 30 Sept 2020, 20:19

@jezek humm, need to check if any retry is done. I don't think it is in messaging-app.

But i have also the issue here sometimes. But i'm in a house where in 10 meters i have 3 different signals...

lduboeuf · 1 Oct 2020, 08:32

So i've quickly looked at the code, don't see any retries at higher level. But don't have all the knowledge how it is handled at lower level. Please report issue there: https://github.com/ubports/ubuntu-touch/issues

AppLee · 1 Oct 2020, 09:06

@lduboeuf , @jezek
Based on wikipedia : https://en.wikipedia.org/wiki/Short_Message_Service_technical_realisation_(GSM)

I think the problem comes from the provider.
Another possibility is that the modem's firmware has a feature allowing retry from the device.

But I don't think it has something to do with UT.
Still it's worth investigating IMHO.

lduboeuf · 1 Oct 2020, 09:14

@AppLee i agree

jezek · 1 Oct 2020, 14:16

@lduboeuf @AppLee I've browsed through the qml code yesterday too and I didn't find any repeating in sending. I made another test, in a hope I would confirm/falsify repeated sending through the app.

Sent SMS to cousin (see posts above for details) - again, the message got gray (with circle), got first billing for SMS (6 cents)
Waited for second (cca 30 s after first) and third billing (cca 1 min after second) - closed the message app.
Waited if there are more billings - Yes more billing, one every 1 minute.
Opened message app, gone to the cousin conversation (to delete the message, cause from previous experience it stops the billings). And I was surprised to see, that the message got green and the billing stopped.

So, from this experiment I deduced, that the message-app tells someone (modem firmware, daemon, ...) to send a message. Than it (the someone) tries to resend the message, until some notification from operator comes, or the message-app tells it to stop trying (message got deleted or marked as green).

Maybe someone with more insight can confirm/falsify my speculation.

jezek · 1 Oct 2020, 14:24

If someone has an idea for a test, that could identify (narrow down, rule out, ...) the culprit, I'm all ears and in testing mood.