A question about background activities in UT

4carlos · 5 Jun 2021, 04:38

User in another forum was asked why Ubuntu Touch connects to Canonical and UBPorts every few minutes. The network traffic was measured with tcpdump. This behavior should be able to be observed with a fresh system without additionally installed apps and occurs when the system is idle. Is there an explanation for this? I'm interested in that too.

Initially some ntpserver belonging to Canonical are queried and

0.push.ubports.com.https.

Thereafter, further calls are made periodically every few minutes:

cactuar.canonical.com.http
davybones.canonical.com.http
0.push.ubports.com.5001

I would expect UT do not open any external connections when idle. It would save the battery and the data plan. What is it good for??

TotalSonic · 6 May 2021, 06:34

From my understanding based on previous threads on this subject (that can be found with a search) the connection to Canonical is done as an initial network check and wake, typical of pretty much every mobile device out there (except it is done with less frequency than what happens with Android and iOS). There was talk of shifting this pinging to a UBports server, but would take some recoding so hasn't happened yet. Next - the traffic every few minutes to the ubports address is to the push server, so the user can receive notifications (for things like Telegram/TELEports, SMS, etc.)

Best regards,
Steve Berson

dobey · 6 May 2021, 17:23

If you have "automatic time" settings configured, then yes, it will check against NTP server occasionally.

As for the rest, the push client does a connectivity check (which hits https://start.ubuntu.com/ currently), and maintains a connection to the UBports push server (push.ubports.com), so that when a push notification is sent, your device can receive it.

Otherwise, as with a traditional Linux distro, you'd need to have many things running in background, and constantly connecting to many different servers, to be able to get notifications, which would definitely eat data and battery.

unrealb2 · 7 May 2021, 02:24

@dobey i wonder if we turn on airplane mode does this ping still occur? I know on android and ios even when you turn on airplane mode it still pings

4carlos · 7 May 2021, 03:30

Hmm, I am asking because my Xperia XA2 with Sailfish does not ping the world after a fresh installation and initial setup without installed apps. It's just quiet and doesn't connect to anyone while idle or in flight mode. Compared to the XA2, the N5 is surprisingly talkative.

OK, it's what it is. I just wanted to know. Thanks for the hints.

unrealb2 · 7 May 2021, 12:38

@4carlos interesting. Wonder how sailfish does it. How do u know if ur phone is pinging

dobey · 7 May 2021, 13:29

@unrealb2 No, it won't, unless you re-enable some network connectivity, as airplane mode disables the radios, so nothing can make a connection to network.

dobey · 7 May 2021, 13:31

@unrealb2 I'm pretty sure Sailfish doesn't have any push notifications support. Also, I think they have integrated automatic time updates from cell tower, rather than using NTP. Some work would need to be done to integrate this in Ubuntu Touch still, though.