Android Apps Not Receiving Incoming Call Notification

[timmehb]

Hi,
Thought best creating a new thread. I see there are numerous others in recent days/weeks of similar nature.

PBX 16.0.9
Android App Versions. Majority on 16.7.6
Hardware Model. Various but specifically CAT S42.
Battery Saving Optimization has been disabled on all handsets.
We have roughly 20-30 of these devices at a particular site, so impact is heavy.

The issue is sporadic, and happens at various times of the day. No link between them. This is why it is hard to troubleshoot.
Wifi connectivity throughout the site, but devices will be roaming between APs.

Incoming Call Notifications are not acknowledged by the 3CX App. The phone doesn't ring, or vibrate.
Immediately after the other party ends the call though, a Missed Notification hits the device. Immediately.... everytime....

PBX Is sending PUSH notifications, verified by both packet captures and within the support log files on 3CX.
We have verified that Google contacts the Android phone at the same time as the incoming call is being made by means of packet captures on our edge routers. Packets with a source port of 5228.

Not to sound dramatic here, but this is absolutely killing productivity and making us look like chumps. We have partner support with our 3CX reseller but this is also going nowhere. This HAS got worse within the last 4 weeks. There has got to be something we can do. At this rate, we'd even opt for less battery life if the 3CX app performed some sort of keepalive.

Please help.

 

[ChrisC_3CX]

Just to first gather a bit more information:

• When you say various device models but specifically CAT S42 do you mean that you have other models on this same network and provisioned to this same PBX but do not face the same issues as the CAT S42s?

• I understand you've already verified Google contacting the devices but please try switching from the Wifi connection to an LTE connection as well, do you get the same exact behavior?

• What Android version are the CAT S42s running?

• Does this issue affect all CAT S42s with no exceptions?

• Are the devices local or remote to the 3CX PBX?

• Launch the 3CX Android App on an affected device, go to "Menu >> Settings >> Advanced" and disable "Telecom API". Try placing a call to that device again and let us know if get the same behavior.

 

[timmehb]

• When you say various device models but specifically CAT S42 do you mean that you have other models on this same network and provisioned to this same PBX but do not face the same issues as the CAT S42s?

We have other devices (Galaxy Devices) that are facing a similar issue.

• I understand you've already verified Google contacting the devices but please try switching from the Wifi connection to an LTE connection as well, do you get the same exact behavior?

These phones are Wifi only phones with no SIM card in. Whilst testing this behaviour, we gave one of the devices a SIM card and worked on LTE only. The same thing occured.

• What Android version are the CAT S42s running?

Android 10

• Does this issue affect all CAT S42s with no exceptions?

Without verifying with each person, we are now hearing direct complaints from 10 out of the 30 people. This isn't linked to a single device.

• Are the devices local or remote to the 3CX PBX?

Our PBX is running on premise. We have numerous sites connected via a VPN. Devices on the same physical site and network as well as remote devices are seeing the issue.

• Launch the 3CX Android App on an affected device, go to "Menu >> Settings >> Advanced" and disable "Telecom API". Try placing a call to that device again and let us know if get the same behavior.

I can do an A/B test as I am on site tomorrow. I will disable this on a number of the affected phones to see if this improves.


I appreciate there are numerous moving parts to this, but there has to be an issue unravelling with the Android application and PUSH notification.

We had a similar issue at the start of the year and was told by 3CX support to create our own Firebase project. And that actually saw an improvement in PUSH notifications and the issue was deemed as resolved from our end. But when we removed the Project with the latest version of v16, things got worse.
I don't know if we're awaiting on improved PUSH notifications in v18 or not - but tensions are high about this issue at the moment.

 

[ChrisC_3CX]

I can do an A/B test as I am on site tomorrow. I will disable this on a number of the affected phones to see if this improves.

Yes please let us know how this goes.

I don't know if we're awaiting on improved PUSH notifications in v18 or not

I think you already got an answer for this.

 

[timmehb]

Yes please let us know how this goes.



I think you already got an answer for this.

I will do the testing and report back.

Can you clairfy on the v18 upgrades. We really need some clarity on what is improving as far as Android Push Notifications go as opposed to how it operates now.
If changes are sufficient, and are coming - then that gives us some ray of hope.

 

[ChrisC_3CX]

Well for information on changes on the 3CX PBX you could have a look at our changelog here: https://www.3cx.com/blog/change-log/phone-system-change-log/

The 3CX Android App specific changelog can be found here: https://www.3cx.com/blog/change-log/3cxphone-android-build-history/

 

[timmehb]

Hi Chris, yes I've read the changelog but the information is not clear.

Do Android Push Notifications improvements exist in v18, or have all improvements found their way into v16.

I'm trying to understand if we're to expect Push notification improvements in v18.

 

[ChrisC_3CX]

have all improvements found their way into v16

With major releases such as v18 most if not all components of the PBX are updated and improved upon. Regarding PUSH, improvements have indeed been made in v16 to bring it to a very good level so in v18 no major changes were made to it, apart from some adjustments to further ensure stability and reliability by eliminating some minor bugs. Anything you see under the V18 tab is exclusive for 3CX V18.

 

[timmehb]

Yes please let us know how this goes.



I think you already got an answer for this.

Can confirm that the Telecom API was already disabled for our phones, on the latest version 16.7.6

What further more can we do, and look into? This is obviously a bit of an issue for us.

 

[ChrisC_3CX]

I'll PM you shortly regarding this.

 

[ChrisC_3CX]

As discussed with @timmehb via PM, the problematic cases have been drastically reduced after the release of 3CX Android version 16.7.8.121 leading us to believe that most cases where related to the fact that the device would not vibrate when silent and 3CX was in the background. This specific behavior was fixed in version 16.7.8.121.