First, I am sorry that I write this in English, but I don't know Dutch yet. However, I decided to post this topic here and not just open a private ticket, because this may be important nearly for all Android users.
The issue is: when you use GTalk (Google Talk chat), you may notice that it disconnects after every few minutes. And then, even though you may still see that you are online, actually you don't get any messages and your messages don't reach the recepient. You can realize it later, when suddenly you get some very delayed message. It is very easy to reproduce. Just leave your phone for 10 minutes and then try to send a message from some other PC to your GTalk.
When this happens, the only way to fix it is to reconnect - "Sign out" and "Sign in" again. And after you do that, you suddenly receive all the delayed chat messages that people sent to you.
Even worse - the same happens to all other Google services. For example, to your GMail notifications. Have you ever noticed that for some reason you didn't get email notification on your mobile in time? That's it.
This issue was known worldwide for a while, sometimes switching mobile providers helped, sometimes switching WiFi routers helped, etc.
But recently this issue got a technical explanation, and Google is aware of it.
In brief, your Android device maintains constant connection to Google servers for push notifications (including those for GMAIL, GTALK etc.). This connection usually does nothing (idle), but when there is some notification, it arrives using this connection. To keep this connection alive, Android sends periodic keepalive messages on it. The problem is that the interval is 28 min for 3G networks. And many mobile operators close idle connections much earlier. That's why this connection is being closed, and you have the issue.
Here is the full explanation: https://productforums.google.com/forum/#!msg/mobile/X0j2BgCVQjI/jkpUW0aI3uIJ
Unfortunately, this happens with SIMYO network as well. Now, technically speaking, it is not purely SIMYO problem - as you can understand from the technical explanation. But SIMYO _can_ maybe make it work. And that's why I would like to ask here if it is possible to solve it, before Google solves that on Android (if this will ever happen).
So what is required, technically speaking, is to ensure that TCP-session to Google servers on port 5228 is kept alive with idle timeout higher than 28 minutes. I would really appreciate your answer on that. This issue causes a lot of problems to Android users worldwide, making many services unusable. Of course, I understand that Google should implement it in other way, but before it happens, it would be really great to have this solution from mobile operators.
P.S. My details: Sony Xperia V with official ROM, Android 4.1.2. Tried several APNs - the default one (apn=portalmmm.nl), the one published on this site (apn=internet), Rabo Mobiel (apn=rabo)...
Beste antwoord door Alex
I know Blackberry's unique selling point is push mail. I thought it is not possible with other devices. Other devices don't support push mail. I'll try to talk with our technical support. Maybe they can fix it.