TCP Out-of-Order - Android App not connecting to Server

asked 2021-01-14 18:50:36 +0000

andernfalls gravatar image

updated 2021-01-15 12:57:55 +0000

Hello everybody,

I'm having a big problem accessing my app externally via Android, unfortunately. Below I would like to summarize everything that would be relevant to this process.

A TomCat web server is running on a Windows Server 2016. The application hosted on it can be opened from Apple devices and browsers without any problems. But I always get the message "The server is not available" when trying to connect via Android. We then suspected that it might be the SSL certificate from Let's Encrypt and installed an SSL certificate from Thawte. However, the problem is still the same.

I made a record using Wireshark to see what the difference was in the queries. I see that for Android query it is logged that TCP Out of Order message appears in the logs.

Unfortunately, however, I cannot interpret this. Is there anyone who can give me a hint what could be the cause of the error? I would be very grateful for any tip.

The relevant records are held by Cloudshark.

Here you can find the Android recording where the connection does not work. ANDROID NOT WORKING

The request comes from the IP address

Here is the iOS recording where the connection works without any problems. IOS WORKING

Addition: I have made and added another recording using "Packet Capture App". Packet Capture

I would be willing to pay 100,-€ for the decisive hint that could lead to the elimination of the problem.

Thank you all for your time.

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Did you try looking at the logcat from the Android phone? If this is app related, then you can see the error messages from the logcat. Also, you could get the syslog from the iOS phone and perform a comparison when you launch the app. Just a suggestion.

Amato_C gravatar imageAmato_C ( 2021-01-15 16:17:19 +0000 )edit