Connectivity lost after sleep with cellular networks

Question

Created Jul ’24

Replies 3

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Hi, I'm using network extension on my VPN app. I'm override the sleep method and send some data to my server when the method call. I noticed that the server requests are succeeded when I'm connecting with a WiFi networks and failed when I'm connecting with cellular networks. Does the OS blocks immediately the connectivity when I'm on the cellular networks and the device enter to sleep?

Answered by DTS Engineer in 794544022

I'm override the sleep method and send some data to my server when the method call.

Is this ‘goodbye’ message something that the server ACKs? Or do you just send it and hope?

The pattern that I’d expect to work is:

The system calls -sleepWithCompletionHandler:.
You send the goodbye request to the server.
You receive the ACK to that.
You then call the completion handler passed to you in step 1.

OTOH, consider this:

The system calls -sleepWithCompletionHandler:.
You send the goodbye message to the server.
You immediately call the completion handler.

Here there’s a race between the goodbye message going out on the ‘wire’ and iOS turning off the application processor.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

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Answer 1

DTS Engineer OP

Apple

Jul ’24

Recommended

I'm override the sleep method and send some data to my server when the method call.

Is this ‘goodbye’ message something that the server ACKs? Or do you just send it and hope?

The pattern that I’d expect to work is:

The system calls -sleepWithCompletionHandler:.
You send the goodbye request to the server.
You receive the ACK to that.
You then call the completion handler passed to you in step 1.

OTOH, consider this:

The system calls -sleepWithCompletionHandler:.
You send the goodbye message to the server.
You immediately call the completion handler.

Here there’s a race between the goodbye message going out on the ‘wire’ and iOS turning off the application processor.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0

Answer 2

or_b OP

Aug ’24

I'm waiting to receive an ACK from the server and then call the completion handler but I never getting the ACK. It happening only in the -sleepWithCompletionHandler method.

0

Answer 3

DTS Engineer OP

Apple

Aug ’24

I'm waiting to receive an ACK from the server and then call the completion handler

OK, then I’d expect that to work. I recommend that you file a bug about this. Please post your bug number, just for the record.

IMPORTANT Make sure to:

Install the VPN (Network Extension) debug profile on your test device.
Include a sysdiagnose taken shortly after reproducing the problem.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0