Unreachable while in background

Question

Hi,

Mobile clients frequently become unreachable even with TLS connection (which is in fact TCP) when the app is in background.

I'm closely monitoring a few mobile clients on our local network. Since they reside on our local network, I discovered that some clients wake up right after they receive an icmp echo request. I wrote a script that pings local clients every 20 seconds so I can effectively keep them alive all the time.

This hack works for the following devices.

Samsung Galaxcy S5 (Android 4.4.2)

Samsung Galaxy A7 (Android 4.4.2)

Huawei P8

But not for

Samsung Galaxy S6 (Android 5.1)

iPhone 5s

The "keep alive wifi" and "stay awake" options don't help.

This is the most annoying issue I found with almost every softphone app.

Is there a generic solution to fix the issue for all devices and non-local clients?

Comments

Something else seems wrong here. This icmp echo should not be necessary. Is that server on the local network as well ?

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Yes the pbx (zyccoo coovox u50) is on the local network. However the icmp echo can be sent from anyone on the same subnet. In fact it is sent from one of our routers that has access to all subnets.

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Hello, does the issue appear in other networks with other servers? It seems to be a network issue of a kind.

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Hello, could you please try using ports different than 5060?