3 ms·

GCM/FCM will delay low priority notifications, in order to batch as many together as possible. On top of that, the cell networks don't allow keeping a socket o

by tjohns 7y ago

GCM/FCM will delay low priority notifications, in order to batch as many together as possible. On top of that, the cell networks don't allow keeping a socket open for more than a few minutes without sending keepalive packets. Unlike on desktop, keeping a socket open isn't "free" on mobile. Waking up the cell radio has a significant penalty on battery life. (And yes, Android batches up process wakeups as well. See the docs on "Doze Mode": https://developer.android.com/training/monitoring-device-state/doze-standby https://developer.android.com/training/monitoring-device-sta...)

AshamedCaptain 7y ago
So you just batch the keepalives, like the old Nokias were doing. Reaching 1 month long battery lifes with Jabber on. Absolutely no difference 1 having to send 1 keepalive every 5 minutes than 30. This is just a subversion of basic networking in order to centralize everything through a single provider and as usual the users are trained to see it as necessary without questioning it.
vinay_ys 7y ago
> On top of that, the cell networks don't allow keeping a socket open for more than a few minutes without sending keepalive packets. Unlike on desktop, keeping a socket open isn't "free" on mobile. You are wrong. Cell networks don't prevent you from keeping a socket open for however long you want. For how to keep your sockets alive, see https://developer.android.com/reference/android/net/SocketKeepalive?hl=en https://developer.android.com/reference/android/net/SocketKe...
- anticensor 7y ago
  Keepalive across cells are not universally available. Most mobile networks renew your IP at each handover.
- tjohns 7y ago
  That method just instructs the OS to send keepalive packets on a system thread. It saves some CPU power by letting your process sleep, but still requires waking the cell radio up periodically. The implementation can be found here: https://github.com/aosp-mirror/platform_frameworks_base/blob/master/core/java/android/net/ConnectivityManager.java https://github.com/aosp-mirror/platform_frameworks_base/blob...
  - vinay_ys 7y ago
    That's right. And it should work as advertised in the documentation. Anyway, I was responding to the "cell networks don't allow" part of your comment. Cell networks don't have a say in what I do at IP/TCP layer.
    - B-Con 7y ago
      They literally said that cell networks don't allow it without the keep alive. You quoted it and said they were wrong because... you can use a keep alive. I'm confused as to what you're correcting.
- namibj 7y ago
  There are collaborations between mobile network providers and push notification providers to get these sockets special-cased. I.e., they won't need keep-alive at any regular interval. So the radio can actually get layer-1 pings (like, when you're called, or get an SMS) for push notifications.

by tjohns 7y ago

AshamedCaptain 7y ago

So you just batch the keepalives, like the old Nokias were doing. Reaching 1 month long battery lifes with Jabber on. Absolutely no difference 1 having to send 1 keepalive every 5 minutes than 30. This is just a subversion of basic networking in order to centralize everything through a single provider and as usual the users are trained to see it as necessary without questioning it.

vinay_ys 7y ago

> On top of that, the cell networks don't allow keeping a socket open for more than a few minutes without sending keepalive packets. Unlike on desktop, keeping a socket open isn't "free" on mobile. You are wrong. Cell networks don't prevent you from keeping a socket open for however long you want. For how to keep your sockets alive, see https://developer.android.com/reference/android/net/SocketKeepalive?hl=en https://developer.android.com/reference/android/net/SocketKe...

anticensor 7y ago
Keepalive across cells are not universally available. Most mobile networks renew your IP at each handover.
tjohns 7y ago
That method just instructs the OS to send keepalive packets on a system thread. It saves some CPU power by letting your process sleep, but still requires waking the cell radio up periodically. The implementation can be found here: https://github.com/aosp-mirror/platform_frameworks_base/blob/master/core/java/android/net/ConnectivityManager.java https://github.com/aosp-mirror/platform_frameworks_base/blob...
- vinay_ys 7y ago
  That's right. And it should work as advertised in the documentation. Anyway, I was responding to the "cell networks don't allow" part of your comment. Cell networks don't have a say in what I do at IP/TCP layer.
  - B-Con 7y ago
    They literally said that cell networks don't allow it without the keep alive. You quoted it and said they were wrong because... you can use a keep alive. I'm confused as to what you're correcting.
namibj 7y ago
There are collaborations between mobile network providers and push notification providers to get these sockets special-cased. I.e., they won't need keep-alive at any regular interval. So the radio can actually get layer-1 pings (like, when you're called, or get an SMS) for push notifications.